ASTIS - Arctic Science and Technology Information System


The ASTIS database contains the following 375 Polar Continental Shelf Program contributions, which are sorted here by contribution number.


Late Wisconsinan glaciation of the central sector of the Canadian High Arctic   /   Lamoureux, S.F.   England, J.H.
(Quaternary research, v. 54, no. 2, Sept. 2000, p. 182-188, ill., maps)
(PCSP/PPCP contribution, no. 002-00)
References.
ASTIS record 48773.
Languages: English
Web: doi:10.1006/qres.2000.2167
Libraries: ACU

Geomorphic and chronological evidence from Cornwall Island in the Canadian High Arctic Archipelago provides direct evidence for the age and dynamics of the center and northern flank of the Innuitian Ice Sheet that covered the islands during the Late Wisconsonian glacial maximum. Dispersal of erratics and glacial landforms, indicate that ice flowed north across the island and converged with ice flowing northwest from Norwegian Bay. Cornwall Island was initially deglaciated at 9000 C14 yr B.P. in near synchrony with widely separated sites in adjacent parts of the archipelago. This regional chronology suggests rapid breakup of a marine-based Innuitian Ice Sheet that was destabilized by rapid eustatic sea-level rise and ice thinning during the early Holocene. This evidence provides strong support for a recently proposed ice divide spanning the central part of the Canadian High Arctic and indicates that most, if not all, of the region was glaciated during the Late Wisconsinan. (Au)

A, B
Deglaciation; Flow; Glacial epoch; Glacial geology; Glacial landforms; Glacial transport; Glaciation; Ice divides; Ice sheets; Recent epoch; Sea level; Sediments (Geology)

G0813, G0815
Cornwall Island, Nunavut; Devon Island, Nunavut; Ellesmere Island, Nunavut; Norwegian Bay, Nunavut


The last glaciation of east-central Ellesmere Island, Nunavut : ice dynamics, deglacial chronology, and sea level change   /   England, J.   Smith, I.R.   Evans, D.J.A.
(Canadian journal of earth sciences, v. 37, no. 10, Oct. 2000, p.1355-1371, ill., maps)
(PCSP/PPCP contribution, no. 007-00)
References.
ASTIS record 48508.
Languages: English
Web: doi:10.1139/cjes-37-10-1355
Libraries: ACU

During the last glacial maximum of east-central Ellesmere Island, trunk glaciers inundated the landscape, entering the Smith Sound Ice Stream. Accelerator mass spectrometry (AMS) dates on individual shell fragments in till indicate that the ice advanced after 19 ka BP. The geomorphic and sedimentary signatures left by the trunk glaciers indicate that the glaciers were polythermal. The configuration and chronology of this ice is relevant to the reconstruction of ice core records from northwestern Greenland, the history of iceberg rafting of clastic sediments to northern Baffin Bay, the reopening of the seaway between the Arctic Ocean and Baffin Bay, and the regional variability of arctic paleoenvironments. Deglaciation began with the separation of Ellesmere Island and Greenland ice at fiord mouths ~8-8.5 ka BP. Ice reached fiord heads between 6.5 and 4.4 ka BP. Trunk glacier retreat from the fiords of east-central Ellesmere Island occurred up to 3000 years later than in west coast fiords. This later retreat was favoured by (1) impoundment by the Smith Sound Ice Stream in Kane Basin until ~8.5 ka BP, which moderated the impact of high summer melt recorded in nearby ice cores between ~11.5 and 8.5 ka BP; (2) the shallow bathymetry and narrowness (<2 km) of the east coast fiords, which lowered calving rates following separation of Innuitian and Greenland ice; and (3) the likelihood of higher precipitation along east Ellesmere Island. Glaciers throughout the field area readvanced during the late Holocene. The greater advance of coastal glaciers is attributed to their proximity to the North Water polynya in Baffin Bay. (Au)

A, D, F
Aspect; Bathymetry; Cores; Deglaciation; Geological time; Geomorphology; Glacial deposits; Glacial landforms; Glaciation; Glaciers; Ice; Mass balance; Mass spectrometry; Moraines; Palaeogeography; Polynyas; Precipitation (Meteorology); Recent epoch; Sea level

G081, G0813, G0815, G09
Bache Peninsula, Nunavut; Baffin Bay-Davis Strait; Buchanan Bay region, Nunavut; Canadian Arctic Islands; Ellesmere Island, Nunavut; Flagler Bay region, Nunavut; Greenland; Herschel, Cape, region, Nunavut; Kane Basin, Greenland/Nunavut; Knud Peninsula, Nunavut; Nares Strait, Greenland/Nunavut; North Water Polynya, Baffin Bay; Nunavut; Princess Marie Bay region, Nunavut; Smith Sound, Greenland/Nunavut; Thorvald Peninsula, Nunavut


Mapping thermal and hydrological conditions beneath a polythermal glacier with radio-echo sounding   /   Copland, L.   Sharp, M.
(Journal of glaciology, v. 47, no.157, 2001, p. 232-242, ill., maps)
(PCSP/PPCP contribution, no. 009-00)
References.
ASTIS record 50642.
Languages: English
Web: doi:10.3189/172756501781832377
Libraries: ACU

Spatial patterns in residual bed reflection power (BRPr), derived from ground-based radio-echo sounding, were mapped and interpreted in terms of the thermal and hydrological conditions at the base of a high-Arctic polythermal glacier (John Evans Glacier, Ellesmere Island, Canada). BRPr is the residual from a statistical relationship between measured bed reflection power and ice thickness that describes the rate of dielectric loss with depth in the glacier. We identified three types of thermal structure: (a) Positive BRPr and an internal reflecting horizon occur over the glacier terminus. The reflecting horizon is interpreted as the boundary between warm and cold ice, and suggests the presence of a warm basal layer. (b) Positive BRPr occurs without an internal reflector in the upper part of the ablation zone. This suggests that ice is at the pressure-melting point only at the bed. (c) Negative BRPr without an internal reflector occurs in all other regions, suggesting cold ice at the bed. Where BRPr is positive, its pattern is similar to the pattern of subglacial water flow predicted from the form of the subglacial hydraulic equipotential surface. This suggests that hydrological conditions at the glacier bed are a major control on BRPr, probably because the dielectric contrast between ice and water is higher than that between ice and other subglacial materials. (Au)

F
Ablation; Drainage; Electrical properties; Flow; Glacial melt waters; Glacier lakes; Glaciers; Mapping; Mathematical models; Measurement; Radar; Temperature; Thermal regimes; Thickness; Topography

G0813
John Evans Glacier, Nunavut


Late Early Permian plant fossils from the Canadian High Arctic : a rare paleoenvironmental/climatic window in northwest Pangea   /   LePage, B.A.   Beauchamp, B.   Pfefferkorn, H.W.   Utting, J.
(Palaeogeography, palaeoclimatology, palaeoecology, v.191, no. 3-4, 20 Feb. 2003, p. 345-372, ill., maps)
(PCSP/PPCP contribution, no. 011-00)
Appendix.
References.
ASTIS record 58086.
Languages: English
Web: doi:10.1016/S0031-0182(02)00671-5
Libraries: ACU

Recently discovered megafossil plant remains in late Early Permian (Kungurian) marine sediments on northern Axel Heiberg Island, Canadian Arctic Archipelago, provide a much needed datum point for paleobiogeographic considerations in this part of North America. The fossil plants represent at least ten families belonging to several major groups (sphenopsids, ferns, pteridosperms, ginkgos, cordaitaleans, and conifers). The conifers Rufloria and Walchia are the most commonly represented taxa, while other gymnosperms constitute much of the remaining collection. Lycopsids are absent and sphenopsids as well as ferns are present, but rare. The plant material probably originated from Crockerland and has a complex taphonomic history. There appears to be a strong phytogeographic connection with the Angaran floral realm. In addition, some floral elements occurring here are known mostly from the Early Mesozoic elsewhere. These findings support the idea that plant evolution was most intensive in extrabasinal settings; with migration into the depositional lowlands often occurring at times when climatic conditions became favorable for range expansion out of the uplands. The Axel Heiberg Island flora is another datum point for rare, but significant late Early Permian age floras on the North American continent. (Au)

B, A, H, E, J, I
Invertebrates; Limestone; Palaeobotany; Palaeoclimatology; Palaeoecology; Palaeogeography; Palaeontology; Palaeozoic era; Palynology; Permian period; Plant anatomy; Plant distribution; Plant taxonomy; Seeds; Sponges; Stratigraphy

G0813, G0815, G14, G10, G06, G02
Arctic waters; Axel Heiberg Island, Nunavut; Canadian Arctic Islands waters; North American Arctic; Russian Arctic


Movements and distribution of polar bears in the Beaufort Sea   /   Amstrup, S.C.   Durner, G.M.   Stirling, I.   Lunn, N.J.   Messier, F.
(Canadian journal of zoology, v. 78, no. 6, June 2000, p. 948-966, ill., maps)
(PCSP/PPCP contribution, no. 013-00)
References.
ASTIS record 48676.
Languages: English
Web: doi:10.1139/cjz-78-6-948
Libraries: ACU

We fitted 173 satellite radio collars (platform transmitter terminals) to 121 adult female polar bears in the Beaufort Sea and relocated the bears 44 736 times between 1985 and 1995. We regularly resighted many instrumented bears so that we could ascertain whether changes in movements or distribution were related to reproductive status. Mean short-term movement rates were less than 2 km/h for all classes of bears. Maximum movement rates occurred in winter and early summer. In the southern Beaufort Sea (SBS), net geographic movements from the beginning to the end of each month were smaller for females with cubs of the year than for solitary females, and larger in November than in April, May, or July. In May, June, July, and August, radio-collared bears in the SBS moved north. They moved south in October. In the northern Beaufort Sea (NBS), bears moved north in June and south in March and September. Total annual movements ranged from 1406 to 6203 km. Mean total distances moved each month ranged from 79 to 420 km. Total monthly movements by SBS bears were largest in early winter and smallest in early spring. In the NBS, movements were largest in summer and smallest in winter. In the SBS, females with cubs moved less each month than other females. Annual activity areas ranged from 7264 to 596 800 km². Monthly activity areas ranged from 88 to 9760 km². Seasonal fidelity to activity areas of bears captured in all parts of the Beaufort Sea was strongest in summer and weakest in spring. (Au)

I, J, G
Ablation; Animal behaviour; Animal distribution; Animal ecology; Animal food; Animal live-capture; Animal physiology; Animal tagging; Formation; Movement; Pack ice; Polar bears; Radio tracking of animals; Sea ice; Seals (Animals)

G07, G04
Banks Island waters, N.W.T.; Canadian Beaufort Sea; Chukchi Sea; Prince Patrick Island waters, N.W.T.


Evolutionary origins of Antarctic microbiota : invasion, selection and endemism   /   Vincent, W.F.
(Antarctic science, v. 12, no. 3, Sept. 2000, p. 374-385, ill.)
(PCSP/PPCP contribution, no. 014-00)
References.
ASTIS record 48582.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/142.pdf
Web: doi:10.1017/S0954102000000420
Libraries: ACU

Increasing interest in the ecological roles, conservation and biotechnological potential of Antarctic microbiota has focused attention on their biodiversity and evolutionary origins. Antarctic microbial ecosystems provide useful models for general questions in evolutionary ecology given the relative isolation of the South Polar Region, the severe biological constraints imposed by the polar environment, and the absence of higher plants and animals in some Antarctic habitats. Sealed environments such as Lake Vostok and the overlying East Antarctic ice sheet provide unique, natural culture collections for studying microorganisms that have been isolated from the global gene pool over timescales of evolutionary significance. Most Antarctic environments, however, continue to receive microbial propagules from outside the region, as indicated by spore trap data, the microflora found in Antarctic snow and ice, the colonising taxa at geothermal sites, and the high frequency of apparently cosmopolitan species in most habitats. Differences in environmental stability and selection pressure among environments are likely to influence the degree of adaptive radiation and microbial endemism. The latter seems greater in the Southern Ocean by comparison with non-marine ecosystems of Antarctica, although there is some evidence of endemic species in highly specialised niches on the continent such as in the endolithic habitat beginning to provide new insights into the genetic affinities and biodiversity of Antarctic microbiota, and are leading to a more rigorous evaluation of microbial endemism. (Au)

H, G, J, I, D, E
Adaptation (Biology); Algae; Animal diseases; Animal distribution; Atmospheric circulation; Bacteria; Biology; Birds; Climate change; Cores; Evolution (Biology); Fishes; Fungi; Genetics; Marine mammals; Microorganisms; Ocean currents; Plant distribution; Protozoa; Refugia; Sea ice; Wildlife habitat; Winds

G15
Antarctic regions; Bellingshausen Sea, Antarctic regions; Ross Sea, Antarctic regions; Vestfold Hills, Antarctic regions; Vostok, Lake, Antarctic regions; Weddell Sea, Antarctic regions


Life on snowball Earth   /   Vincent, W.F.   Howard-Williams, C.
(Science, v.287, no.5462, 31 Mar. 2000, p.2421, 1 ill.)
(PCSP/PPCP contribution, no. 015-00)
References.
ASTIS record 57772.
Languages: English
Web: doi:10.1126/science.287.5462.2421b
Libraries: ACU

In his News Focus article "An appealing snowball Earth that's still hard to swallow" (10 Mar., p. 1734), Richard A. Kerr provides an update on the "snowball Earth" hypothesis, which proposes that around 600 and 2400 million years ago in the Proterozoic era there were several global ice ages interspersed with periods of global warming. One of the primary criticisms of the snowball Earth hypothesis is that thick sea ice over the entire world ocean would cut off the supply of sunlight to organisms in the seawater below and thereby eliminate photosynthesis. Others have similarly concluded that global-scale freezing would extinguish all surface life. Yet vast, biologically diverse cryo-ecosystems occur today throughout the Arctic and Antarctica. The closest analog to Proterozoic snowball Earth may be the thick (20 to 100 meters) landfast sea ice in the modern-day polar regions. On the McMurdo Ice Shelf in Antarctica and on the Ward Hunt Ice Shelf in the Canadian High Arctic, large areas (100 to 1000 square kilometers) of thick sea ice contain surface communities of highly pigmented microbial mats. These perennial mats are frozen into the ice and are inactive through most of the year. They thaw out for a brief (days to weeks) period of photosynthetic activity in late summer when meltwaters form on or in the ice despite air temperatures that are below 0°C. The modern-day ice shelf communities in both polar regions are dominated by oscillatorian cyanobacteria, a group that is widely distributed in the Proterozoic fossil record. These mat-forming organisms produce microhabitats for other biota, including viruses, bacteria, protists, and metazoa. The ice-mat environment offers protection against the effects of ultraviolet radiation and freeze-up and could have similarly provided refuge for the survival, growth, and evolution of less tolerant biota during the proposed Proterozoic glaciations. The alternation of global freeze-up and hothouse conditions during the Proterozoic might also help to explain the eurythermal characteristics of cyanobacteria that dominate in today's polar regions. The extreme cold tolerance of these organisms combined with their high-temperature optima for growth would seem to be an ideal strategy for surviving the "freeze-fry" travails of ancient Earth. (Au)

J, H, G, B, A
Bacteria; Cold adaptation; Cyanophyceae; Evolution (Biology); Glacial epoch; Ice shelves; Marine ecology; Microbial ecology; Microorganisms; Palaeobotany; Palaeoclimatology; Photosynthesis; Plant distribution; Plant growth; Proterozoic era; Protozoa; Puddles; Sea ice; Sea ice ecology; Thickness

G15, G0813
Antarctic regions; McMurdo Ice Shelf, Antarctic regions; Ward Hunt Ice Shelf, Nunavut


Small scale plant distribution within a polar desert plateau, central Ellesmere Island, Canada   /   Lévesque, E.
(Écoscience, v. 8, no 3, 2001, p. 350-358, ill., 1 map)
(PCSP/PPCP contribution, no. 018-00)
References.
ASTIS record 50486.
Languages: English
Libraries: ACU

In order to quantify the availability of vacant favourable or "safe" microsites, the spatial distribution of plants on a sparsely vegetated dolomitic plateau was studied in central Ellesmere Island (Canada). Vegetation (vascular plants and bryophytes), boulders and polygon margins were mapped to the closest centimetre in a 10 m × 5 m plot and the microtopography of 8.5 m × 5 m of that plot was surveyed at a 10 cm × 10 cm scale. Vascular plant density was low (6.9 plants/m²). Individuals of the most frequent species found in the plot totalled 300 for Draba subcapitata Simm., 8 for Saxifraga oppositifolia L. and 27 for Papaver radicatum Rottb. Many plants grew in flat microsites in proximity to boulders and larger plants of the same species indicating successful, though infrequent, reproduction on the site. Still, the total uncolonized area including microsites around boulders and plants was much larger than the area occupied by plants (total plant cover = 0.16%). Clearly, vacant microsites were abundant on this polar desert plateau. However, the rare occurrence of established plants, in spite of the presence of viable seeds, implies that for an available microsite to become a favourable one, additional conditions must be met, such as moisture availability and higher temperatures. Adequate conditions may be met only infrequently, during favourable years. (Au)

H, E, J
Bioclimatology; Bryophytes; Growing season; Mapping; Meteorology; Microclimatology; Plant cover; Plant distribution; Plant ecology; Plant growth; Plant nutrition; Plant reproduction; Plant-soil relationships; Plants (Biology); Polar deserts; Precipitation (Meteorology); Topography; Winds

G0813
Ellesmere Island, Nunavut; Sverdrup Pass, Nunavut


Modern pollen assemblages in lake sediments from the Canadian Arctic   /   Gajewski, K.
(Arctic, antarctic, and alpine research, v. 34, no. 1, Feb. 2002, p. 26-32, ill., maps)
(PCSP/PPCP contribution, no. 021-00)
References.
ASTIS record 51831.
Languages: English
Web: doi:10.2307/1552505
Libraries: ACU

Modern pollen assemblages from lakes in the Canadian high-arctic and middle-arctic vegetation zones are used to document geographic differences in pollen deposition. There are differences in the pollen percentages of the herbaceous taxa that can be used to discriminate the various regions of the Arctic. High-arctic pollen assemblages have higher Poaceae, while middle-arctic sediments have higher Cyperaceae percentages. Pollen spectra from Banks Island contain higher percentages of Saxifragaceae, Brassicaceae, and Tubuliflorae, while lake sediments from the central Arctic contain more Ranunculaceae and Caryophyllaceae pollen. Salix and Oxyria pollen percentages are relatively high in samples from Ellesmere Island. Pollen from the low-arctic and boreal zones can comprise a significant component of the assemblages in arctic sediments, and this is more important in the southern islands of the Canadian Arctic Archipelago. (Au)

B, H, E, F, J
Bottom sediments; Brassicaceae; Caryophyllaceae; Climatology; Geology; Grasses; Lakes; Mountain sorrel; Plant distribution; Plant nutrition; Plants (Biology); Pollen; Saxifraga; Sedges; Sedimentation; Spores; Taiga ecology; Tundra ecology; Willows

G0812, G0813
Axel Heiberg Island, Nunavut; Bathurst Island, Nunavut; Boothia Peninsula, Nunavut; Canadian Arctic Islands; Cornwallis Island, Nunavut; Devon Island, Nunavut; Ellesmere Island, Nunavut; Prince of Wales Island, Nunavut; Victoria Island, N.W.T./Nunavut


Farthest north lake and fjord populations of calanoid copepods, Limnocalanus macrurus and Drepanopus bengei in the Canadian High Arctic   /   Van Hove, P.   Swadling, K.M.   Gibson, J.A.E.   Belzile, C.   Vincent, W.F.
(Polar biology, v. 24, no. 5, Apr. 2001, p. 303-307, ill., maps)
(PCSP/PPCP contribution, no. 023-00)
References.
ASTIS record 50272.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/147.pdf
Web: doi:10.1007/s003000000207
Libraries: ACU

The zooplankton assemblages of Lake A and Disraeli Fjord, northern Ellesmere Island (83°N, 75°W), were surveyed in early summer 1999. In permanently ice-covered Lake A, two glacial relict calanoid copepod species (Drepanopus bungei and Limnocalanus macrurus) were found in the top 30 m. All developmental stages of the more abundant D. bungei were present, whereas only adults of L. macrurus were found. Analysis of gut contents showed that L. macrurus preyed upon the smaller species. A net tow sample of zooplankton from Disraeli Fjord was mainly composed of D. bungei and L. macrurus, along with two marine cyclopoid copepods (Oncaea borealis and Oithona similis). These two zooplankton communities occur within unusual environments that are strongly influenced by perennial ice and snow. They will be subject to major habitat disruption should the current warming trends continue in the north polar region. (Au)

I, E, H, D, F, J
Animal distribution; Animal food; Biological sampling; Biomass; Climate change; Copepoda; Fresh-water biology; Internal organs; Lakes; Melting; Necropsy; Ocean temperature; Phytoplankton; Salinity; Sea ice ecology; Temperature; Water masses; Wildlife habitat; Zooplankton

G03
Disraeli Fiord region, Nunavut; Disraeli Fiord, Nunavut


Ice-shelf collapse, climate change, and habitat loss in the Canadian High Arctic   /   Vincent, W.F.   Gibson, J.A.E.   Jeffries, M.O.
(Polar record, v. 37, no.201, Apr. 2001, p. 133-142, ill., map)
(PCSP/PPCP contribution, no. 024-00)
References.
ASTIS record 50372.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/149.pdf
Web: doi:10.1017/S0032247400026954
Libraries: ACU

Early explorers in the Canadian High Arctic described a fringe of thick, landfast ice along the 500-km northern coast of Ellesmere Island. This article shows from analyses of historical records, aerial photographs, and satellite imagery (ERS-l, SPOT, RADARSAT -1) that this ancient ice feature ('Ellesmere Ice Shelf) underwent a 90% reduction in area during the course of the twentieth century. In addition, hydrographic profiles in Disraeli Fiord (83°N, 74°W) suggest that the ice-shelf remnant that presently dams the fiord (Ward Hunt Ice Shelf) decreased in thickness by 13 m (27%) from 1967 to 1999. Mean annual air temperatures at nearby Alert station showed a significant warming trend during the last two decades of this period, and a significant decline in the number of freezing degree days per annum. The ice-dammed fiord provides a stratified physical and biological environment (epishelf lake) of a type that is otherwise restricted to Antarctica. Extensive meltwater lakes occur on the surface of the ice shelf and support a unique microbial food web. The major contraction of these ice-water habitats foreshadows a much broader loss of marine cryo-ecosystems that will accompany future warming in the High Arctic. (Au)

F, A, D, J, E, V
Calving (Ice); Climate change; Coasts; Expeditions; Explorers; Fjords; Food chain; Fresh-water ecology; Glacial melt waters; Glacier lakes; History; Ice cover; Ice shelves; Marine ecology; Melting; Meteorology; Ocean temperature; Radar; Salinity; Scientists; Thickness; Travels; Water masses

G0813, G03
Alert, Nunavut; Arctic Ocean; Disraeli Fiord, Nunavut; Ward Hunt Ice Shelf, Nunavut


The first 20 years (1978-1979 to 1998-1999) of ice-wedge growth at the Illisarvik experimental drained lake site, western Arctic coast, Canada   /   Mackay, J.R.   Burn, C.R.
(Canadian journal of earth sciences, v. 39, no. 1, Jan. 2002, p. 95-111, ill., maps)
(PCSP/PPCP contribution, no. 027-00)
References.
ASTIS record 51908.
Languages: English
Web: doi:10.1139/e01-048
Libraries: ACU

In August 1978, a large tundra lake was drained to study the aggradation of permafrost into newly exposed lake-bottom sediments. Ice-wedge growth, which started in the first winter following drainage, had ceased in most of the lake bottom within about twelve years. The gradual cessation of thermal contraction cracking can be attributed to rapid vegetation growth, snow entrapment, an increase in winter ground temperatures, and a decrease in the linear coefficient of thermal contraction associated with freeze-thaw consolidation of the initially saturated lake-bottom sediments. The tilt and separation of markers in the active layer revealed gradual convergence towards the troughs even after ice-wedge growth had ceased. For the first few years the ice-wedge growth rate was up to 3 cm/a as determined by excavation, drilling, separation of the bottoms of benchmarks installed into permafrost, and divergence of free-floating inductance coils placed on the sides of ice wedges well below the bottom of the active layer. The vertical extent of most ice wedges was probably about 2 m, as deduced from the depths of ice-wedge cracks and the geometries of the wedge tops. Many thermal contraction cracks propagated upward to the ground surface from the tops of the ice wedges rather than downward from the ground surface. Small, upward facing, horizontal steps and vertical slickensided surfaces in permafrost on both sides of an excavated ice wedge near its top indicated that the adjacent permafrost had moved upward, relative to the wedge, from thermal expansion during the warming period. (Au)

C, F, H
Active layer; Bottom sediments; Ice wedges; Lakes; Permafrost beneath lakes; Plant growth; Soil temperature; Thermal expansion; Thermal properties

G0812
Illisarvik Lake, N.W.T.; Mackenzie Delta, N.W.T.


Carrying capacity of wetland habitats used by breeding Greater Snow Geese   /   Massé, H.   Rochefort, L.   Gauthier, G.
(The Journal of wildlife management, v. 65, no. 2, Apr. 2001, p. 271-281, 1 ill., 1 map)
(PCSP/PPCP contribution, no. 034-00)
References.
ASTIS record 50452.
Languages: English
Web: doi:10.2307/3802906
Libraries: ACU

Because geese can damage their arctic breeding habitats through overgrazing, there is debate about limiting the rapid growth of the greater snow goose (Chen caerulescens atlantica) population and setting a population goal. To answer these questions, we assessed the nutritional carrying capacity of freshwater wetland habitats for breeding greater snow geese at the Bylot Island colony, Nunavut, Canada. Specifically, we (1) mapped the different types of wetlands on the island; (2) estimated net aboveground primary production of these habitats: (3) compared total food availability with predicted total food requirements of the current population; and (4) validated our predictions of plant biomass consumed by comparing them to the intensity of goose grazing measured. Freshwater wetlands represented 173 ±6km² or 11% of the total area of the south plain of Bylot Island. Streams and wet polygons were the most important habitats in terms of availability of suitable forage plants for geese. The average net above-ground primary production ranged from 21.0 ±4.6 along lakes to 46.0 ±9.8 g/m² in polygon channels. We estimated the total food supply available for geese in wetlands at 2,625 ±461 tons in 1997 but only 1,247 ±473 tons in 1996, a year of low plant production. We predicted a summer food requirement for goslings at 8.1 ±0.6 kg/bird, for breeding adults at 7.9 ±2.3, and for nonbreeding adults at 4.7 ±1.5, and we predicted the total summer food requirements of the goose population at 1,201 ±160 tons. The predicted amount of biomass removed (32 ±7%) agreed well with the actual amount of biomass removed measured in mid-August (39 ±11%) in 1997, bt not in 1996 (67 ±27% vs 26 ±17%, respectively), possibly because the goose population was lower that year due to poor breeding success. In 1997, the goose population was at 46 ±10% of the theoretical short-term carrying capacity (341,000 geese) of the wetlands of Bylot Island. We recommend keeping the goose population below this theoretical carrying capacity. (Au)

I, A, H, N
Animal food; Animal population; Biomass; Grazing; Greater Snow Geese; Mapping; Plants (Biology); Primary production (Biology); Sedges; Wetlands; Wildlife habitat; Wildlife management

G0813
Bylot Island, Nunavut


Periphytic diatom assemblages from Bathurst Island, Nunavut, Canadian High Arctic : an examination of community relationships and habitat preferences   /   Lim, D.S.S.   Kwan, C.   Douglas, M.S.V.
(Journal of phycology, v. 37, no. 3, June 2001, p. 379-392, ill., map)
(PCSP/PPCP contribution, no. 036-00)
References.
ASTIS record 50495.
Languages: English
Web: doi:10.1046/j.1529-8817.2001.037003379.x
Libraries: ACU

Diatoms are potentially the most important biomonitors of environmental change in high arctic lakes and ponds, but to date few autecological data are available. Because of the shallow nature of many of these water bodies, a large proportion of taxa are periphytic and planktonic diatoms are absent for the most part. By determining the microhabitat and substrate preferences of these benthic diatom taxa, the potential exists to infer past changes in available habitats from fossil diatom assemblages collected from sediment cores and ultimately to reconstruct past environmental and climatic changes responsible for these shifts in habitat availability. To refine our understanding of high arctic diatom habitat preference, the common diatom taxa found on submerged moss (bryophyte), sediment, and rock substrates from lakes and ponds on Bathurst Island, Nunavut, Canadian High Arctic were examined. The relationships among key limnological variables and the common taxa from each habitat were examined. Many diatom taxa exhibited varying degrees of microhabitat preference, with moss representing the more unique habitat. In addition, the following limnological variables significantly (P<=0.05) explained the species variance for each of the three substrates: Na+ and total nitrogen for moss; total phosphorus (filtered) and pH for rock; and Fe3+, total phosphorus (unfiltered), total nitrogen, temperature, and pH for sediment. These data can be used to help interpret monitoring and paleolimnological studies in this environmentally sensitive region. (Au)

H, J, B, E, F
Biomass; Bottom sediments; Chemical properties; Climate change; Diatoms; Fresh-water biology; Fresh-water ecology; Lakes; Mosses; Phytoplankton; Plant distribution; Plant taxonomy; Rocks; Temperature; Tundra ponds

G0813
Bathurst Island, Nunavut


Flow dynamics and iceberg calving rates of Devon Ice Cap, Nunavut, Canada   /   Burgess, D.O.   Sharp, M.J.   Mair, D.W.F.   Dowdeswell, J.A.   Benham, T.J.
(Journal of glaciology, v. 51, no.173, 2005, p. 219-230, ill., maps)
(PCSP/PPCP contribution, no. 628-00)
References.
This PCSP/PPCP contribution number is incorrect. The correct number is unknown.
ASTIS record 61087.
Languages: English
Web: doi:10.3189/172756505781829430
Libraries: ACU

The surface velocity field of Devon Ice Cap, Nunavut, Canada, was mapped using interferometric synthetic aperture radar (InSAR). Ascending European Remote-sensing Satellite 1 and 2 (ERS-1/-2) tandem mode data were used for the western and southeast sectors, and 3 day repeat pass ERS-1 imagery for the northeast sector. Speckle-tracking procedures were used with RADARSAT 1 imagery to obtain surface velocities over the terminus of Belcher Glacier (a major calving front) where decorrelation between ERS data occurred. The InSAR data highlight a significant contrast in ice-flow dynamics between the east and west sides of the ice cap. Ice movement west of the main north-south divide is dominated by relatively uniform 'sheet' flow, but three fast-flowing outlet glaciers that extend 14-23 km beyond the ice-cap margin also drain this region. Several outlet glaciers that extend up to 60 km inland from the eastern margin drain the eastern side of the ice cap. The dominant ice-flow regimes were classified based on the relationship between the driving stress (averaged over a length scale of ten ice thicknesses) and the ratio of surface velocity to ice thickness. The mapped distribution of flow regimes appears to depict the spatial extent of basal sliding across the ice cap. This is supported by a close relationship between the occurrence of flow stripes on the ice surface and flow regimes where basal sliding was found to be an important component of the glacier motion. Iceberg calving rates were computed using measured surface velocities and ice thicknesses derived from airborne radio-echo sounding. The volume of ice calved between 1960 and 1999 was estimated to be 20.5 ±4.7 km³ (or 0.57 km³/a). Approximately 89% of this loss occurred along the eastern margin. The largest single source is Belcher Glacier, which accounts for ~50% of the total amount of ice calved. (Au)

G, F, E, J
Ablation; Calving (Ice); Climate change; Deformation; Drainage; Effects of climate on ice; Environmental impacts; Flow; Glacial melt waters; Glacier variations; Glaciers; Ice caps; Ice divides; Ice sheets; Icebergs; Mapping; Mathematical models; Measurement; Movement; Radar; SAR; Satellites; Sea level; Stress; Thickness; Tides; Topography; Velocity

G0813, G0815
Belcher Glacier, Nunavut; Croker Bay, Nunavut; Devon Ice Cap, Nunavut; Sverdrup Glacier, Nunavut


Lacustrine sedimentary environments in High Arctic proglacial Bear Lake, Devon Island, Nunavut, Canada   /   Lamoureux, S.F.   Gilbert, R.   Lewis, T.
(Arctic, antarctic, and alpine research, v. 34, no. 2, May 2002, p. 130-141, ill., maps)
(PCSP/PPCP contribution, no. 001-01)
References.
ASTIS record 51833.
Languages: English
Web: doi:10.2307/1552464
Libraries: ACU

Combined catchment, subbottom acoustic, and sedimentary studies of high arctic, proglacial Bear Lake, Devon Island, were carried out to evaluate the role lacustrine processes and Holocene catchment evolution have had on the sedimentary record. In the proximal basin, bottom deposits up to 60 m thick are generated in part by turbid underflows associated with peak meltwater flow from the Devon Island Ice Cap. These underflows produce rhythmically laminated structures that are likely varves. In shallower locations, accumulation is slower and results from homopycnal distribution of fine suspended sediment throughout the proximal basin, resulting in a simple varve couplet. The distal basin is isolated from glacial meltwater by a shallow sill, although some fine-grained detrital carbonate transported by the glacial meltwater is deposited in both basins. In most locations in the distal basin Holocene sediments are less than 10 m thick. They are composed primarily of massive clay and some carbonate interrupted by irregular graded carbonate units produced by sporadic heavy summer rainfall and sediment transport from small plateau tributaries. Eolian sedimentation is also important throughout the lake, especially when high accumulations melt through the ice in the proximal basin, producing isolated grains and layers of coarse sand in the sedimentary record. Holocene ice margin changes have influenced the sedimentary record substantially, particularly during the mid-Holocene when the ice cap is inferred to have retreated from the catchment. (Au)

B, E, F, J
Bottom sediments; Cores; Geomorphology; Glacial melt waters; Ice caps; Lakes; Mathematical models; Melting; Meteorology; Palaeoecology; Precipitation (Meteorology); Recent epoch; Sediment transport; Sedimentary rocks; Sedimentation; Suspended solids; Wind erosion

G0813
Bear Lake, Nunavut


Incubation behaviour of Greater Snow Geese in relation to weather conditions   /   Poussart, C.   Gauthier, G.   Larochelle, J.
(Canadian journal of zoology, v. 79, no. 4, Apr. 2001, p. 671-678, ill.)
(PCSP/PPCP contribution, no. 002-01)
References.
ASTIS record 50481.
Languages: English
Web: doi:10.1139/cjz-79-4-671
Libraries: ACU

Based on allometric considerations, goose species with larger body masses should spend more time on their nest during incubation than smaller ones. We documented hourly and daily variations in incubation behaviour of large goose species nesting in the Arctic, the greater snow goose (Chen caerulescens atlantica), and examined the effect of weather conditions on recess frequency and duration. Incubation behaviour was inferred from variations in temperature recorded by adding artificial eggs to clutches. Mean nest attentiveness during the incubation period was 91.4%, indicating that it can be relatively low even for a large goose. Females took 5-6 recesses/day, which lasted for an average of 22.7 min each. Variability in incubation behaviour over time was greater within females than among females. Recesses were more frequent, and of longer duration, in the afternoon than at night. Females were also less attentive to their nest as incubation progressed, a consequence of both an increase in recess frequency and duration, except in the days before hatching, when nest attentiveness rose abruptly. The relatively low nest attendance of incubating greater snow geese may be a consequence of the opportunity to feed close to the nest during recesses. Weather parameters influenced movements away from the nests in 11 of the 12 females monitored. Females took more recesses when wind velocity was low and, to a lesser extent, when air temperature and solar radiation were high, but the response was quite variable among females. Although females seem to adjust their behaviour in order to limit egg cooling, variations in risk of predation according to time of day may also influence incubation patterns. (Au)

I, E
Animal behaviour; Animal food; Animal reproduction; Arctic foxes; Atmospheric humidity; Atmospheric temperature; Bioclimatology; Biological clocks; Bird nesting; Glaucous Gulls; Greater Snow Geese; Heat transmission; Jaegers; Meteorology; Microclimatology; Precipitation (Meteorology); Predation; Ravens; Size; Solar radiation; Thermal properties; Velocity; Winds

G0813
Bylot Island, Nunavut


Are goose nesting success and lemming cycles linked? Interplay between nest density and predators   /   Bêty, J.   Gauthier, G.   Giroux, J.-F.   Korpimäki, E.
(Oikos, v. 93, no. 3, June 2001, p. 388-400, ill.)
(PCSP/PPCP contribution, no. 003-01)
References.
ASTIS record 50468.
Languages: English
Web: doi:10.1034/j.1600-0706.2001.930304.x
Libraries: ACU

The suggested link between lemming cycles and reproductive success of arctic birds is caused by potential effects of varying predation pressure (the Alternative Prey Hypothesis, APH) and protective association with birds of prey (the Nesting Association Hypothesis, NAH). We used data collected over two complete lemming cycles to investigate how fluctuations in lemming density were associated with nesting success of greater snow geese (Anser caerulescens atlanticus) in the Canadian High Arctic. We tested predictions of the APH and NAH for geese breeding at low and high densities. Goose nesting success varied from 22% to 91% between years and the main egg predator was the arctic fox (Alopex lagopus). Nesting associations with snowy owls (Nyctea scandiaca) were observed but only during peak lemming years for geese nesting at low density. Goose nesting success declined as distance from owls increased and reached a plateau at 550 m. Artificial nest experiments indicated that owls can exclude predators from the vicinity of their nests and thus reduce goose egg predation rate. Annual nest failure rate was negatively associated with rodent abundance and was generally highest in low lemming years. This relationship was present even after excluding goose nests under the protective influence of owls. However, nest failure was inversely density-dependent at high breeding density. Thus, annual variations in nest density influenced the synchrony between lemming cycles and oscillations in nesting success. Our results suggest that APH is the main mechanism linking lemming cycles and goose nesting success and that nesting associations during peak lemming years (NAH) can enhance this positive link at the local level. The study also shows that breeding strategies used by birds (the alternative prey) could affect the synchrony between oscillations in avian reproductive success and rodent cycles. (Au)

I
Animal behaviour; Animal distribution; Animal population; Arctic foxes; Biological productivity; Bird nesting; Glaucous Gulls; Greater Snow Geese; Jaegers; Lemmings; Predation; Raptors; Ravens; Testing; Voles

G0813
Bylot Island, Nunavut


Spatial and temporal changes in sedimentary processes at proglacial Bear Lake, Devon Island, Nunavut, Canada   /   Lewis, T.   Gilbert, R.   Lamoureux, S.F.
(Arctic, antarctic, and alpine research, v. 34, no. 2, May 2002, p. 119-129, ill., maps)
(PCSP/PPCP contribution, no. 004-01)
References.
ASTIS record 51832.
Languages: English
Web: doi:10.2307/1552463
Libraries: ACU

Lacustrine sedimentary processes are identified on an intra-annual scale at proglacial Bear Lake, Devon Island. Stage recorders, recording thermistors, sediment traps, and underflow monitoring equipment were deployed during the 1999 melt season. Episodic proximal turbidity currents were measured as positive near-bottom temperature anomalies and currents. The timing of individual positive temperature anomalies was clearly associated with diurnal peaks of discharge into the lake. During the period of 23 to 25 July, continuous underflow occurred which preceded a large discharge event by about 24 h. Sediment traps placed throughout the lake recorded sediment accumulation rates from 16 June to 4 August. An extremely large precipitation event occurred on 29 June, when coarse, carbonate-rich sediment was deposited in front of a secondary tributary by spatially limited turbidity currents. A niveo-eolian deposit was observed on the lake ice, and sediment traps were deployed under this area. Mass accumulation rates in these traps locally overwhelmed fluvially generated sedimentation. This sediment was dominantly sand, which quickly melted through the lake ice and hastened the date of localized break-up. (Au)

B, F, E, J
Geomorphology; Glacial melt waters; Hydrology; Instruments; Lakes; Measurement; Precipitation (Meteorology); River discharges; Runoff; Sand; Sediment transport; Sedimentation; Spatial distribution; Stream flow; Suspended solids; Temporal variations

G0813
Bear Lake, Nunavut


Avian orientation at steep angles of inclination : experiments with migratory white-crowned sparrows at the magnetic North Pole   /   Åkesson, S.   Morin, J.   Muheim, R.   Ottosson, U.
(Proceedings of the Royal Society of London. Series B. Biological sciences, v.268, no.1479, 22 Sept. 2001, p.1907-1913, ill., map)
(PCSP/PPCP contribution, no. 005-01)
References.
ASTIS record 76141.
Languages: English
Web: doi:10.1098/rspb.2001.1736
Libraries: ACU

The Earth's magnetic field and celestial cues provide animals with compass information during migration. Inherited magnetic compass courses are selected based on the angle of inclination, making it difficult to orient in the near vertical fields found at high geomagnetic latitudes. Orientation cage experiments were performed at different sites in high Arctic Canada with adult and young white-crowned sparrows (Zonotrichia leucophrys gambelii) in order to investigate birds' ability to use the Earth's magnetic field and celestial cues for orientation in naturally very steep magnetic fields at and close to the magnetic North Pole. Experiments were performed during the natural period of migration at night in the local geomagnetic field under natural clear skies and under simulated total overcast conditions. The experimental birds failed to select a meaningful magnetic compass course under overcast conditions at the magnetic North Pole, but could do so in geomagnetic fields deviating less than 3° from the vertical. Migratory orientation was successful at all sites when celestial cues were available. (Au)

I, B, J
Adaptation (Biology); Animal behaviour; Animal live-capture; Animal migration; Biological clocks; Buntings; Diurnal variations; Geomagnetism; Light; North Magnetic Pole; Passeriformes; Photoperiodism; Seasonal variations; Sparrows; Temporal variations; Testing

G0812, G0813
Ellef Ringnes Island, Nunavut; Inuvik, N.W.T.; Resolute, Nunavut


Phylogenetic relationships and infraspecific variation in Canadian Arctic Poa based on chloroplast DNA restriction site data   /   Gillespie, L.J.   Boles, R.
(Canadian journal of botany, v. 79, no. 6, June 2001, p. 679-701)
(PCSP/PPCP contribution, no. 008-01)
References.
ASTIS record 50506.
Languages: English
Web: doi:10.1139/cjb-79-6-679
Libraries: ACU

Infraspecific variation and phylogenetic relationships of Canadian Arctic species of the genus Poa were studied based on chloroplast DNA (cpDNA) variation. Restriction site analysis of polymerase chain reaction amplified cpDNA was used to reexamine the status of infraspecific taxa, reconstruct phylogenetic relationships, and reexamine previous classification systems and hypotheses of relationships. Infraspecific variation was detected in three species, but only in Poa hartzii Gand. did it correspond to infraspecific taxa where recognition of subspecies ammophila at the species level is supported. Additional variation in P. hartzii ssp. hartzii is hypothesized to be the result of hybridization with Poa glauca in the High Arctic and subsequent introgression resulting in repeated transfer of P. glauca DNA. The variation in Poa pratensis L. had a geographical rather than taxonomic basis, and is hypothesized to correspond to indigenous arctic versus introduced extra-arctic populations. In P. glauca Vahl cpDNA variation was detected only in western Low Arctic and boreal populations and may represent greater variation where the species survived the Pleistocene glaciations. Cladistic parsimony analysis of cpDNA restriction site data mostly confirms recent infrageneric classification systems. Poa alpina L., along with the non-arctic Poa annua L. and Poa sect. Sylvestres, formed the basalmost clades. The remaining taxa group into two main clades: one consisting of Poa sects. Poa, Homalopoa, Madropoa and Diocopoa; the second, of Poa sects. Secundae, Pandemos, Abbreviatae and Stenopoa. Poa sect. Poa, comprising Poa arctica R. Br. and P. pratensis, is a strongly supported monophyletic group, not closely related to P. alpina. Poa hartzii is confirmed as a member of a paraphyletic or weakly supported P. sect. Secundae. Poa glauca and Poa abbreviata R. Br. are distinct members within a generally unresolved Poa. sect. Stenopoa-Abbreviatae complex. (Au)

H
Evolution (Biology); Genetics; Grasses; Plant distribution; Plant taxonomy

G081, G0813, G0812, G02, G0826
Arctic regions; Canadian Arctic; Canadian Arctic Islands; Nouveau-Québec


The distribution of basal motion beneath a High Arctic polythermal glacier   /   Copland, L.   Sharp, M.J.   Nienow, P.   Bingham, R.G.
(Journal of glaciology, v. 49, no.166, 2003, p. 407-414, ill., maps)
(PCSP/PPCP contribution, no. 009-01)
References.
ASTIS record 55560.
Languages: English
Web: doi:10.3189/172756503781830511
Libraries: ACU

The longitudinal pattern of surface velocity of a large, predominantly cold, polythermal glacier (John Evans Glacier, Ellesmere Island, Canada) was measured over summer and winter periods. In the accumulation and upper ablation areas, where ice is predominantly cold-based, summer velocities were slightly higher than overwinter velocities. Predicted velocities due to ice deformation alone in these areas closely matched these observations in the winter, with limited basal motion likely in the summer. In the lower ablation area, where ice is likely warm-based, measured summer velocities were up to double overwinter velocities. Predicted ice deformation could not account for all of these measured velocities in either summer or winter. This suggests that basal motion occurs throughout the year over at least part of the lower ablation area. This finding is supported by radio-echo sounding, subglacial drainage reconstructions and analyses of early-summer meltwater chemistry, which suggest that subglacial water is present throughout the year in this region. In summer, basal motion may account for up to 75% of the total surface velocity throughout the lower ablation area. The inferred rate of basal motion increases sharply directly below a set of moulins by which most surface meltwater reaches the glacier bed. (Au)

F, E, J
Ablation; Chemical properties; Crevasses; Deformation; Diurnal variations; Drainage; Effects of climate on ice; Flow; Glacial melt waters; Glacier lakes; Glacier surges; Glacier variations; Glaciers; Hydrology; Measurement; Melting; Radar; Seasonal variations; Temperature; Temporal variations; Velocity

G0813, G06, G10
Greenland; John Evans Glacier, Nunavut; McCall Glacier, Alaska; White Glacier, Nunavut


Slope sediment yield in arid lowland continuous permafrost environments, Canadian Arctic Archipelago   /   Lewkowicz, A.G.   Kokelj, S.V.
(Catena (Giessen), v. 46, no. 4, 1 Feb. 2002, p. 261-283, ill., maps)
(PCSP/PPCP contribution, no. 012-01)
References.
ASTIS record 59657.
Languages: English
Web: doi:10.1016/S0341-8162(01)00156-4
Libraries: ACU

Surface wash erosion was measured at runoff plots on low to moderate slopes in clayey and sandy silts underlain by continuous permafrost on the Fosheim Peninsula, Ellesmere Island. Due to snow redistribution in winter, total precipitation on the plots varied from 34 to 150 mm, with corresponding surface runoff values of 0 to 102 mm. Where runoff occurred, at least 80% of it was derived from snowmelt. Suspended sediment removal was <75 g/m²/a at relatively well-vegetated sites but averaged more than 1200 g/m²/a at a plot where the vegetation had been removed by landsliding. Niveo-aeolian deposition was greater than suspended sediment removal at some plots, indicating net accumulation. Solute removal ranged up to 80 g/m²/a and exceeded clastic sediment transport at one vegetated site. Elevated rates of erosion at the sites of detachment slides that pre-date 1950 demonstrated that terrain disturbance in permafrost environments can affect slopewash processes for at least several decades. Plot data (precipitation, vegetation and surface grain-size) from the Fosheim Peninsula and Banks Island were used to develop a statistical model of suspended sediment removal by surface wash on undisturbed slopes. For any given grain-size, the model predicts a rise in erosion from zero precipitation (because of an absence of runoff) to a peak at about 50 mm, a decline as precipitation increases to 300 mm and a further increase in erosion beyond this inflection point. This non-linear response is due to the complex interaction of moisture (primarily snow) and vegetation cover. Erosion at any given precipitation value varies through three orders of magnitude depending on surface grain-size. The maximum erosion predicted is 1 kg/m²/a for a runoff plot with 1100 mm of precipitation, a corresponding vegetation cover of 77% and a median surface grain-size of 7 phi. (Au)

C, A, F, J, E
Erosion; Landslides; Mathematical models; Measurement; Permafrost; Plant cover; Plant distribution; Precipitation (Meteorology); Runoff; Sediment transport; Sediments (Geology); Silt; Slopes; Snow; Snowmelt; Stream erosion; Suspended solids

G0813, G0812
Banks Island, N.W.T.; Fosheim Peninsula, Nunavut


Dramatic orientation shift of White-Crowned Sparrows displaced across longitudes in the High Arctic   /   Åkesson, S.   Morin, J.   Muheim, R.   Ottosson, U.
(Current biology, v. 15, no. 17, 6 Sept. 2005, p.1591-1597, ill.)
(PCSP/PPCP contribution, no. 016-01)
References.
ASTIS record 57417.
Languages: English
Web: doi:10.1016/j.cub.2005.07.027
Libraries: ACU

Advanced spatial-learning adaptations have been shown for migratory songbirds, but it is not well known how the simple genetic program encoding migratory distance and direction in young birds translates to a navigation mechanism used by adults. A number of convenient cues are available to define latitude on the basis of geomagnetic and celestial information, but very few are useful to defining longitude. To investigate the effects of displacements across longitudes on orientation, we recorded orientation of adult and juvenile migratory white-crowned sparrows, Zonotrichia leucophrys gambelii, after passive longitudinal displacements, by ship, of 266-2862 km across high-arctic North America. After eastward displacement to the magnetic North Pole and then across the 0° declination line, adults and juveniles abruptly shifted their orientation from the migratory direction to a direction that would lead back to the breeding area or to the normal migratory route, suggesting that the birds began compensating for the displacement by using geomagnetic cues alone or together with solar cues. In contrast to predictions by a simple genetic migration program, our experiments suggest that both adults and juveniles possess a navigation system based on a combination of celestial and geomagnetic information, possibly declination, to correct for eastward longitudinal displacements. (Au)

I, J, L, E
Adaptation (Biology); Age; Animal behaviour; Animal ecology; Animal live-capture; Animal migration; Animal nervous systems; Bioclimatology; Biological clocks; Bird nesting; Climatology; Clouds; Diurnal variations; Genetics; Geomagnetism; Icebreakers; Marine transportation; Navigation; North Magnetic Pole; Seasonal variations; Solar radiation; Sparrows; Spatial distribution; Testing

G0813, G0812, G0815
Baffin Island, Nunavut; Banks Island, N.W.T.; Canadian Arctic Islands waters; Devon Island, Nunavut; Ellef Ringnes Island waters, Nunavut; Ellef Ringnes Island, Nunavut; Ellesmere Island, Nunavut; Inuvik region, N.W.T.; Iqaluit, Nunavut; Melville Island, N.W.T./Nunavut


Clock-shift experiments with Savannah sparrows, Passerculus sandwichensis, at high northern latitudes   /   Muheim, R.   Åkesson, S.
(Behavioral ecology and sociobiology, v. 51, no. 4, Mar. 2002, p. 394-401, ill.)
(PCSP/PPCP contribution, no. 017-01)
References.
ASTIS record 76134.
Languages: English
Web: doi:10.1007/s00265-002-0458-2
Libraries: ACU

Orientation can be difficult for nocturnal bird migrants at high northern latitudes because of the large changes of magnetic declinations, rapid longitudinal time-shifts experienced during a long-distance flight and the invisibility of stars during the polar summer. Both sunset cues as well as geomagnetic cues have been shown to be of great importance in the orientation system of Savannah sparrows, Passerculus sandwichensis. We used clock-shift experiments to investigate whether geomagnetic and sunset cues were used for migratory orientation by wild-caught young Savannah sparrows at high geomagnetic latitudes in Northern Canada. We exposed birds to a 4-h slow clock-shift, expecting a 60° clock-wise shift in orientation after the treatment. Under natural clear skies in the local geomagnetic field, the birds responded by showing a significant axial mean orientation directed towards the position of the setting sun in the NW and towards their preferred migratory direction in the SE. After exposure to the clock-shift for 6 days and nights the birds showed a clear response to the treatment and shifted significantly towards NNE. Birds that first oriented towards NW in the experiments before clock-shift tended to shift clock-wise, thus reacted to the clock-shift in the expected way. The reaction of the individual birds that originally oriented towards SE seems to vary. In summary, our birds did not select a constant angle (menotaxis) in relation to the sun's position during the experiments, but presumably were affected by the sun showing phototaxis or followed their magnetic compass. Possible explanations of the unexpected experimental results are discussed. (Au)

I, B, J
Adaptation (Biology); Animal behaviour; Animal live-capture; Animal migration; Biological clocks; Diurnal variations; Geomagnetism; Light; Passeriformes; Photoperiodism; Seasonal variations; Sparrows; Testing

G0812
Inuvik, N.W.T.


Cold springs in permafrost on Earth and Mars   /   Andersen, D.T.   Pollard, W.H.   McKay, C.P.   Heldmann, J.
(Journal of geophysical research, v.107, no. E 3, 5015, Mar. 2002, p. 4-1 - 4-7, ill., maps)
(PCSP/PPCP contribution, no. 020-01)
References.
ASTIS record 51783.
Languages: English
Web: doi:10.1029/2000JE001436
Libraries: ACU

Perennial springs located on west central Axel Heiberg Island in the Canadian High Arctic occur in a region with a mean annual air temperature of -15 °C and flow through continuous permafrost 600 m thick. The spring water is a low-temperature (up to 6 °C) brine that maintains constant discharge temperatures and flow rates throughout the year. Here we report on observations of temperature and discharge rate of these springs and develop a combined flow and thermal model of the subsurface flow using the measured geothermal gradient. We also consider the implications these springs have for the search for similar environments, past or present, on Mars. (Au)

F, C, B, E, I, H, G
Atmospheric temperature; Evaporation; Flow; Geothermal investigations; Glacial melt waters; Glacier lakes; Groundwater; Heat budgets; Hydrology; Lake ice; Mathematical models; Microorganisms; Minerals; Permafrost; Polar deserts; Precipitation (Meteorology); River discharges; Salinity; Seasonal variations; Springs (Hydrology); Temperature; Thermal properties; Thermal regimes; Travertine; Velocity

G0813, G0815
Axel Heiberg Island, Nunavut; Expedition Fiord region, Nunavut; Expedition Fiord, Nunavut


Links between short-term velocity variations and the subglacial hydrology of a predominantly cold polythermal glacier   /   Copland, L.   Sharp, M.J.   Nienow, P.W.
(Journal of glaciology, v. 49, no.166, 2003, p. 337-348, ill., maps)
(PCSP/PPCP contribution, no. 023-01)
References.
ASTIS record 55559.
Languages: English
Web: doi:10.3189/172756503781830656
Libraries: ACU

The surface velocity of a predominantly cold polythermal glacier (John Evans Glacier, Ellesmere Island, Canada) varies significantly on both seasonal and shorter time-scales. Seasonal variations reflect the penetration of supraglacial water to the glacier bed through significant thicknesses of cold ice. Shorter-term events are associated with periods of rapidly increasing water inputs to the subglacial drainage system. Early season short-term events immediately follow the establishment of a drainage connection between glacier surface and glacier bed, and coincide with the onset of subglacial outflow at the terminus. A mid-season short-term event occurred as surface melting resumed following cold weather, and may have been facilitated by partial closure of subglacial channels during this cold period. There is a close association between the timing and spatial distribution of horizontal and vertical velocity anomalies, the temporal pattern of surface water input to the glacier, and the formation, seasonal evolution and distribution of sub-glacial drainage pathways. These factors presumably control the occurrence of high-water-pressure events and water storage at the glacier bed. The observed coupling between surface water inputs and glacier velocity may allow predominantly cold polythermal glaciers to respond rapidly to climate-induced changes in surface melting. (Au)

F, E, J
Ablation; Crevasses; Diurnal variations; Drainage; Effects of climate on ice; Electrical properties; Flow; Glacial melt waters; Glacier lakes; Glacier surges; Glaciers; Hydrology; Measurement; Melting; Seasonal variations; Seismic sounding; Suspended solids; Temperature; Temporal variations; Velocity; Weather stations

G0813
John Evans Glacier, Nunavut


The Laurentide and Innuitian ice sheets during the last glacial maximum   /   Dyke, A.S.   Andrews, J.T.   Clark, P.U.   England, J.H.   Miller, G.H.   Shaw, J.   Veillette, J.J.
(Quaternary science reviews, v. 21, no. 1-3, Jan. 2002, p. 9-31, ill., maps)
(PCSP/PPCP contribution, no. 028-01)
References.
ASTIS record 76526.
Languages: English
Web: doi:10.1016/S0277-3791(01)00095-6
Libraries: ACU

The Late Wisconsinan advance of the Laurentide Ice Sheet started from a Middle Wisconsinan interstadial minimum 27-30 14C ka BP when the ice margin approximately followed the boundary of the Canadian Shield. Ice extent in the Cordillera and in the High Arctic at that time was probably similar to present. Ice advanced to its Late Wisconsinan (stage 2) limit in the northwest, south, and northeast about 23-24 14C ka BP and in the southwest and far north about 20-21 14C ka BP. In comparison to some previous reconstructions of ice extent, our current reconstruction has substantially more Late Wisconsinan ice in the High Arctic, where an Innuitian Ice Sheet is generally acknowledged to have existed, in the Atlantic Provinces, where ice is now thought to have extended to the Continental Shelf edge in most places, and on eastern Baffin Island, where ice probably extended to the fiord mouths rather than to the fiord heads. Around most of the ice margin, the Late Wisconsinan maximum ice extent either exceeded the extent of earlier Wisconsinan advances or it was similar to the Early Wisconsinan advance. Ice marginal recession prior to 14 14C ka BP occurred mainly in deep water and along the southern terrestrial fringe. However, Heinrich event 1 probably drew down the entire central ice surface at 14.5 14C ka BP sufficiently to displace the Labrador Sector outflow centre 900 km eastward from the coast of Hudson Bay. The onset of substantial ice marginal recession occurred about 14 14C ka BP in the northwest, southwest, and south but not until about 10-11 14C ka BP in the northeast and in the High Arctic. Thus, the period of maximum ice extent in North America generally encompasses the interval from ~24/21 to 14 14C ka BP, or considerably longer than the duration of the LGM defined as occurring during a period of low global sea level as well as during a time of relative climate stability ~18 14C ka BP. The interval of advance of much of the Laurentide Ice Sheet to its maximum extent (between ~27 14C ka BP and ~24 14C ka BP) coincides with a suggested interval of rapid fall in global sea level to near LGM levels. (Au)

A, F, E, B, H, I
Deglaciation; Flow; Geological time; Glacial deposits; Glacial epoch; Glacial erosion; Glacial melt waters; Glaciation; Laurentide Ice Sheet; Moraines; Palaeobotany; Palaeogeography; Palaeohydrology; Petrology; Pleistocene epoch; Radiocarbon dating; Recent epoch; Refugia; Sea level; Sedimentation; Stratigraphy

G081, G0811, G0813, G08, G0825, G08
Atlantic Provinces; Baffin Island, Nunavut; Melville Island, N.W.T./Nunavut; Old Crow River region, Alaska/Yukon; Ontario


Bio-optical characteristics of the snow, ice, and water column of a perennially ice-covered lake in the High Arctic   /   Belzile, C.   Vincent, W.F.   Gibson, J.A.E.   Van Hove, P.
(Canadian journal of fisheries and aquatic sciences, v. 58, no. 12, Dec. 2001, p.2405-2418, ill., maps)
(PCSP/PPCP contribution, no. 031-01)
References.
ASTIS record 50541.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/160.pdf
Web: doi:10.1139/cjfas-58-12-2405
Libraries: ACU

Lake A is a meromictic, perennially ice-covered lake located at the northern limit of North America (latitude 83°N, Ellesmere Island, Canada). In early June 1999, only 0.45% of incident photosynthetically available radiation (PAR) was transmitted through its 2-m ice and 0.5-m snow cover. Removal of snow from 12 m² increased PAR under the ice by a factor of 13 and biologically effective ultraviolet radiation (UVR) by a factor of 16 (from 0.4% to 6.3% of incident). The diffuse attenuation coefficient (Kd) for UVR was substantially lower in the ice than in the underlying freshwater (e.g., 50% lower at 320 nm), indicating the exclusion of chromophoric dissolved organic matter (CDOM) during freeze-up or the subsequent degradation of CDOM retained in the ice. Peak phytoplankton concentrations occurred immediately under the ice, and a broad maximum of photosynthetic sulfur bacteria and associated sulfur particles was observed over the depth interval 20-45 m at <0.005% of incident PAR. Climate-induced changes in the overlying snow and ice have the potential to cause major habitat disruption (UV exposure, PAR, temperature, mixing regime) for these stratified, extreme-shade communities. (Au)

F, G, H, E, J
Bacteria; Climate change; Colored dissolved organic matter; Fresh-water ecology; Ice cover; Lake ice; Lakes; Photosynthesis; Phytoplankton; Primary production (Biology); Snow cover; Ultraviolet radiation

G0813
Marvin Peninsula, Nunavut


Evidence for reversal of basin polarity during carbonate ramp development in the Mesoproterozoic Borden Basin, Baffin Island   /   Sherman, A.G.   James, N.P.   Narbonne, G.M.
(Canadian journal of earth sciences, v. 39, no. 4, Apr. 2002, p. 519-538, ill., maps)
(PCSP/PPCP contribution, no. 032-01)
References.
ASTIS record 51914.
Languages: English
Web: doi:10.1139/e01-089
Libraries: ACU

Distribution of facies in the lower half of the Bylot Supergroup suggests overall westward deepening of the Mesoproterozoic Borden Basin. In marked contrast, the upper half of the succession records a reversal in the overall bathymetric trend, such that the eastern portion underwent relative deepening as the west experienced relative shallowing. Strata deposited during this reversal belong to the Victor Bay Formation, a ramp composed predominantly of limestone. Karsting of carbonate strata and development of an angular unconformity in the west contrast with back-stepping and drowning of the ramp in the east, followed by mantling by deep-water limestone, carbonaceous carbonate, and turbidites. Increased accommodation space during this time, via both tectonic subsidence and eustatic sea-level rise, led to a profusion of stromatolite pinnacle reefs and large biostromes. The reversal of basin polarity is best reconciled with development of a distal foreland basin superimposed on the Borden aulacogen. Crustal rethickening and uplift occurred along reactivated basement faults during an eastward-directed compressional event and could be related to thrusting of similar age and vergence in the Coppermine River Group of northwestern Canada. (Au)

B, A, D, H
Bathymetry; Carbonate rocks; Karst; Limestone; Plate tectonics; Proterozoic era; Sea level; Sedimentary structures; Stratigraphy; Stromatolites; Structural geology

G0813, G0815
Baffin Island, Nunavut; Borden Peninsula waters, Nunavut; Borden Peninsula, Nunavut; Bylot Island, Nunavut


Limnological characteristics of 38 lakes and ponds on Axel Heiberg Island, High Arctic Canada   /   Michelutti, N.   Douglas, M.S.V.   Muir, D.C.G.   Wang, X.   Smol, J.P.
(International review of hydrobiology, v. 87, no. 4, July 2002, p. 385-399, ill., maps)
(PCSP/PPCP contribution, no. 035-01)
References.
ASTIS record 59817.
Languages: English
Web: doi:10.1002/1522-2632(200207)87:4<385::AID-IROH385>3.0.CO;2-3
Libraries: ACU

The limnological characteristics of 38 lakes and ponds on Axel Heiberg Island were determined, in part, to establish baseline data for future monitoring programs, and to provide the foundation for future paleoenvironmental work in this climatically-sensitive region. In general, these sites were slightly alkaline, oligotrophic to ultra-oligotrophic (mean total unfiltered phosphorus = 4.1 µg/L), and phosphorus-limited. Principal components analyses separated lakes along a primary gradient of ionic concentration, and along a secondary gradient of POC, DOC and nutrient concentrations. Some interesting aspects of this limnological survey included very acidic sites (pH < 4), and the minimal effects of large altitudinal and latitudinal gradients on the limnological characteristics of our sites. (Au)

F, J, H, I, E, B
Air pollution; Animal waste products; Biological productivity; Carbon; Chemical properties; Chlorophyll; Climate change; Dissolved organic carbon; Drainage; Effects monitoring; Electrical properties; Fresh-water biology; Geology; Grazing; Heavy metals; Lakes; Metals; Nitrogen; Outliers; Phosphorus; Physical properties; Phytoplankton; Plant nutrition; Plant-water relationships; Plants (Biology); Primary production (Biology); Seasonal variations; Solar radiation; Trace elements; Tundra ecology; Tundra ponds; Ungulates; Water pH; Water quality; Waterfowl

G0813
Axel Heiberg Island, Nunavut; Colour Lake, Nunavut


Characterization of High Arctic stream diatom assemblages from Cornwallis Island, Nunavut, Canada   /   Antoniades, D.   Douglas, M.S.V.
(Canadian journal of botany, v. 80, no. 1, Jan. 2002, p. 50-58, ill., maps)
(PCSP/PPCP contribution, no. 036-01)
References.
ASTIS record 51816.
Languages: English
Web: doi:10.1139/b01-133
Libraries: ACU

Distinct diatom assemblages often characterize stream habitats, providing the potential to reconstruct past precipitation, snowmelt, and streamflow levels in high arctic watersheds by analyzing fossil assemblages preserved in downstream lake sediments. Diatom assemblages were studied from seven streams and two rivers surrounding Lake Sophia, Cornwallis Island, Nunavut, Canada (75° 06' N, 93° 36' W). A total of 64 diatom taxa were identified from epilithic and epiphytic assemblages in these lotic habitats. Of these, certain diatom taxa exhibited clear microhabitat preferences. Hannaea arcus (Ehrenberg) Patrick, Achnanthes minutissima (Kützing) Hustedt, Achnanthes petersenii Hustedt, and Meridion circulare (Greville) Agardh were the most common taxa on epilithic substrates, and as a group made up 61-95% of the diatom epilithon. Achnanthes taxa (mainly A. petersenii and A. minutissima) were the dominant taxa in moss habitats, representing between 45 and 73% of the diatom epiphyton. The relative abundance of H. arcus in epilithic habitats was negatively correlated with water temperature (r² = 0.71, n = 8). Hannaea arcus was found in greater abundances in cool, fast-flowing streams. This apparent correlation may more closely reflect current speed, which is inversely correlated to temperature in these streams. When these streams discharge into lake basins, the characteristic stream diatoms H. arcus and M. circulare are deposited in lakes. These diatom taxa have the potential to infer past streamflows using paleolimnological techniques. (Au)

H, F, J, B, E
Biomass; Bottom sediments; Climate change; Diatoms; Effects of temperature on plants; Fresh-water ecology; Lakes; Mosses; Plant taxonomy; Rivers; Rocks; Sedimentation; Snowmelt; Stream flow

G0813
Cornwallis Island, Nunavut; Sophia Lake region, Nunavut; Sophia Lake, Nunavut


U-Pb geochronology of detrital zircons in metasedimentary rocks from southern Baffin Island : implications for the Paleoproterozoic tectonic evolution of northeastern Laurentia   /   Scott, D.J.   Stern, R.A.   St-Onge, M.R.   McMullen, S.M.
(Canadian journal of earth sciences, v. 39, no. 5, May 2002, p. 611-623, ill., maps)
(PCSP/PPCP contribution, no. 037-01)
References.
ASTIS record 51966.
Languages: English
Web: doi:10.1139/e01-093
Libraries: ACU

A geochronological investigation of metasedimentary rocks from southern Baffin Island using the Geological Survey of Canada SHRIMP II (sensitive high-resolution ion microprobe) has characterized the ages of detrital zircon populations to determine their provenance, bracket timing of deposition, and distinguish potentially distinct sequences of rocks. Four lithologically and structurally distinct metasedimentary packages have been identified; each appears to have been derived from a different source region. In the structurally lowest package, all analysed zircons are Archean, and >90% have ages between 2.83 and 2.63 Ga; these rocks are interpreted as the northernmost exposures of the Paleoproterozoic Povungnituk Group of the Cape Smith Belt, northern Quebec, with detritus derived from the Superior craton. Occupying the intermediate structural levels, the most abundant supracrustal rocks on southern Baffin Island are siliciclastic and carbonate units of the Lake Harbour Group, and the Tasiuyak paragneiss. Five samples show a dominantly Paleoproterozoic signature (2.2-1.9 Ga), with only rare Archean zircons; the provenance of this detritus is uncertain. In the distinct package of feldspathic quartzite and pelite that stratigraphically overlies the Lake Harbour Group, all of the analysed detrital grains are Archean, ~80% are >2.83 Ga, with a small proportion of the grains in excess of 3.0 Ga; all of this material is thought to be derived from the Archean craton exposed on the Hall Peninsula east of the study area. Finally, at the highest structural level, a sample associated with the Hall Peninsula orthogneisses contains zircons with prominent modes at 2.92, 2.82, and 2.77 Ga, consistent with derivation from the surrounding orthogneisses. (Au)

B
Archaean era; Geological time; Gneiss; Proterozoic era; Radioactive dating; Sedimentation; Stratigraphy; Structural geology; Zircon

G0813, G0826
Baffin Island, Nunavut; Big Island (62 43 N, 70 43 W), Nunavut; Ungava, Péninsule d', Québec


The first 20 years (1978-1979 to 1998-1999) of active-layer development, Illisarvik experimental drained lake site, western Arctic coast, Canada   /   Mackay, J.R.   Burn, C.R.
(Canadian journal of earth sciences, v. 39, no. 11, Nov. 2002, p.1657-1674 ill., maps)
(PCSP/PPCP contribution, no. 040-01)
References.
ASTIS record 51924.
Languages: English
Web: doi:10.1139/e02-068
Libraries: ACU

Active-layer thickness, snow depth, minimum soil temperatures, near-surface ground ice, soil heave, and permafrost temperatures have been measured for over 20 years following the 1978 artificial drainage of Lake Illisarvik. Measurements of active-layer thickness and other variables have been made at 25-m intervals along the major and minor axes of the oval-shaped drained-lake bed. Permafrost aggradation commenced in the lake bottom during the first winter following drainage. Before the establishment of vegetation, there was little snow cover, minimum ground temperatures were low, and the active layer was relatively thin. However, both snow depth and minimum ground temperatures have risen where vegetation has grown, the active layer has thickened, and in response, the temperature in permafrost has gradually increased. In the lake bottom, the change in snow depth associated with vegetation growth has been the dominant control on variation in active-layer thickness and not summer weather conditions, which are well correlated with thaw depths along an active-layer course established in the adjacent tundra. Changes in elevation of the surface of the lake bed have been measured with respect to some 40 bench marks anchored in permafrost, and indicate vertical movements of the surface associated with frost heave, thaw subsidence, and the growth of aggradational ice. The ground ice content of near-surface permafrost determined by drilling is in close agreement with the measured uplift of the lake bed. The rate of growth of aggradational ice has been ~0.5 cm/a over 20 years. (Au)

C, F, H, A, J
Active layer; Frost heaving; Frozen ground; Ground ice; Hummocks; Lakes; Permafrost; Permafrost beneath lakes; Plant cover; Plant distribution; Snow; Soil temperature; Thaw settlement; Thermokarst

G0812
Garry Island, N.W.T.; Illisarvik Lake, N.W.T.; Richards Island, N.W.T.; Tuktoyaktuk Peninsula, N.W.T.


The oriented lakes of Tuktoyaktuk Peninsula, western Arctic coast, Canada : a GIS-based analysis   /   Côté, M.M.   Burn, C.R.
(Permafrost and periglacial processes, v. 13, no. 1, Mar. 2002, p. 61-70, ill., maps)
(PCSP/PPCP contribution, no. 041-01)
References.
ASTIS record 51851.
Languages: English
Web: doi:10.1002/ppp.407
Libraries: ACU

The orientation, size and shape of 578 lakes on Tuktoyaktuk Peninsula were obtained from 1 : 250 000 Canadian National Topographic Survey map sheets, using ArcView geographic information system. These lakes are outside the glacial limits in a tundra plain with <15m relief. The lakes range from 20 to 1900 ha, and have mean orientation N07°E, with standard error 1.6°. The maps show 145 former lake basins, with lakes inset in 130 of these. The mean orientations of the basins and inset lakes are not statistically different from each other or the general population. Several theories have been proposed for the origin of the oriented lakes, and one theory attributes the orientation to cross winds establishing currents that preferentially erode the ends of the lakes. Data from Tuktoyaktuk and Nicholson for 1970-95 indicate a consistent wind regime within the region, with prevailing winds from the east and west. Using data from Nicholson, a geometric model generates resultant lake orientations of N if all winds are considered, and N08°E if winds above 30km/h are used. The coincidence of the modelled orientation and lake statistics supports the efficacy of cross wind-induced effects in orienting the lakes. The similar orientation of existing lakes and former basins suggests that these processes have been effective for at least several centuries. (Au)

F, C, E, B
Erosion; Geographic information systems; Ground ice; Lakes; Mathematical models; Physical geography; Sediments (Geology); Tundra ponds; Winds

G0812
Tuktoyaktuk Peninsula, N.W.T.


Physical and chemical characteristics of the active layer and permafrost, Herschel Island, western Arctic coast, Canada   /   Kokelj, S.V.   Smith, C.A.S.   Burn, C.R.
(Permafrost and periglacial processes, v. 13, no. 2, Apr./June 2002, p. 171-185, ill., maps)
(PCSP/PPCP contribution, no. 042-01)
References.
ASTIS record 51853.
Languages: English
Web: doi:10.1002/ppp.417
Libraries: ACU

Physical and geochemical characteristics of near-surface permafrost and the impact of permafrost degradation on soil and water chemistry were investigated at five sites on Herschel Island, Yukon Territory. The distribution of soluble cations, moisture and organic matter content in turbic cryosols from undisturbed terrain indicated a thaw unconformity 50 to 80 cm below the base of the present active layer. Palaeoactive-layer depth, estimated at between 90 and 100 cm, is less than at comparable sites in the Mackenzie Delta area. The difference may be due to the comparative proximity of Herschel Island to the Beaufort Sea coastline in the early Holocene. Soluble cations in permafrost and the active layer of static cryosols at recently disturbed sites were two orders of magnitude higher than in the active layer at undisturbed sites. Na+ was the dominant cation in undisturbed permafrost, recently disturbed ground, and surface runoff derived from disturbed areas. Although degradation of permafrost following terrain disturbance has resulted in surface salinization, a condition detrimental to vegetation growth, leaching of soluble salts from disturbed areas has occurred over time. These processes have produced a range of soil conditions that contribute to the floristic diversity of Herschel Island. (Au)

C, F, A, E, J, B
Active layer; Climate change; Cores; Electrical properties; Environmental impacts; Geochemistry; Ground ice; Moisture content of permafrost; Palaeoclimatology; Periglacial landforms; Permafrost; Physical properties; Plant distribution; Plant growth; Runoff; Salinity; Soil chemistry; Soils; Thawing; Thermal protection of permafrost; Tundra ponds

G0811, G0813, G0812
Fosheim Peninsula, Nunavut; Herschel Island, Yukon; Mackenzie Delta, N.W.T.


Shared predators and indirect trophic interactions : lemming cycles and Arctic-nesting geese   /   Bêty, J.   Gauthier, G.   Korpimäki, E.   Giroux, J.-F.
(Journal of animal ecology, v. 71, no. 1, Jan. 2002, p. 88-98, ill.)
(PCSP/PPCP contribution, no. 043-01)
References.
ASTIS record 51898.
Languages: English
Web: doi:10.1046/j.0021-8790.2001.00581.x
Libraries: ACU

1. We investigated the hypothesis that cyclic lemming populations indirectly affect arctic nesting greater snow geese (Anser caerulescens atlanticus L.) through the behavioural and numerical responses of shared predators. 2.The study took place on Bylot Island in the Canadian High Arctic during two lemming cycles. We recorded changes in foraging behaviour and activity rate of arctic foxes, parasitic jaegers, glaucous gulls and common ravens in a goose colony during one lemming cycle and we monitored denning activity of foxes for 7 years. We also evaluated the total response of predators (i.e. number of eggs depredated). 3. Arctic foxes were more successful in attacking lemmings than goose nests because predators were constrained by goose nest defence. Predators increased their foraging effort on goose eggs following a lemming decline. 4. Activity rates in the goose colony varied 3·5-fold in arctic foxes and 4·8-fold in parasitic jaegers, and were highest 2 and 3 years after the lemming peak, respectively. The breeding output of arctic foxes appeared to be driven primarily by lemming numbers. 5. Predators consumed 19-88% of the annual goose nesting production and egg predation intensity varied 2·7-fold, being lowest during peak lemming years. Arctic foxes and parasitic jaegers were the key predators generating marked annual variation in egg predation. 6. Our study provides strong support for short-term, positive indirect effects and long-term, negative indirect effects of lemming populations on Arctic-nesting geese. The outcome between these opposing indirect effects is probably an apparent competition between rodents and many terrestrial Arctic-nesting birds. (Au)

I, J
Animal behaviour; Animal distribution; Animal mortality; Animal population; Arctic foxes; Bird nesting; Denning; Glaucous Gulls; Greater Snow Geese; Lemmings; Parasitic Jaegers; Predation; Ravens; Trophic levels

G0813
Bylot Island, Nunavut


Avian orientation : effects of cue-conflict experiments with young migratory songbirds in the High Arctic   /   Åkesson, S.   Morin, J.   Muheim, R.   Ottosson, U.
(Animal behaviour, v. 64, no. 3, Sept. 2002, p. 469-475, ill.)
(PCSP/PPCP contribution, no. 048-01)
References.
ASTIS record 76139.
Languages: English
Web: doi:10.1006/anbe.2002.3077
Libraries: ACU

The migratory orientation of juvenile white-crowned sparrows, Zonotrichia leucophrys gambelli, was investigated by orientation cage experiments in manipulated magnetic fields performed during the evening twilight period in northwestern Canada in autumn. We did the experiments under natural clear skies in three magnetic treatments: (1) in the local geomagnetic field; (2) in a deflected magnetic field (mN shifted -90°); and (3) after exposure to a deflected magnetic field (mN -90°)) for 1 h before the cage experiment performed in the local geomagnetic field at dusk. Subjects showed a mean orientation towards geographical east in the local geomagnetic field, north of the expected migratory direction towards southeast. The sparrows responded consistently to the shifted magnetic field, demonstrating the use of a magnetic compass during their first autumn migration. Birds exposed to a cue conflict for 1 h on the same day before the experiment, and tested in the local geomagnetic field at sunset, showed the same northerly orientation as birds exposed to a shifted magnetic field during the experiment. This result indicates that information transfer occurred between magnetic and celestial cues. Thus, the birds' orientation shifted relative to available sunset and geomagnetic cues during the experimental hour. The mean orientation of birds exposed to deflected magnetic fields prior to and during testing was recorded up to two more times in the local geomagnetic field under natural clear and overcast skies before release, resulting in scattered mean orientations. (Au)

I, B, J
Adaptation (Biology); Animal behaviour; Animal live-capture; Animal migration; Biological clocks; Diurnal variations; Geomagnetism; Light; Passeriformes; Photoperiodism; Seasonal variations; Sparrows; Testing

G0812
Inuvik, N.W.T.


Natural infection by intestinal cestodes : variability and effect on growth in Greater Snow Goose goslings (Chen caerulescens atlantica)   /   Righi, M.   Gauthier, G.
(Canadian journal of zoology, v. 80, no. 6, June 2002, p.1077-1083, ill.)
(PCSP/PPCP contribution, no. 051-01)
References.
ASTIS record 51842.
Languages: English
Web: doi:10.1139/z02-089
Libraries: ACU

We determined the species of intestinal helminths in Greater Snow Goose (Chen caerulescens atlantica) goslings and examined annual variability in infection levels over a 5-year period on Bylot Island, Nunavut. The intestines of 112 wild goslings collected when near fledging were examined. We also evaluated the effect of intestinal parasites on growth and behaviour of captive goslings in a controlled experiment. In 2000, one group (n = 11) was treated with anthelmintic drugs (Piperazine 52 for nematodes and Droncit for cestodes) and the other (n = 14) was used as a control. Four hymenolepidid cestodes were identified: Drepanidotaenia lanceolata, Hymenolepis barrowensis, Microsom acanthus setigera, and Retinometra longivaginata. No nematodes were detected. Prevalence of intestinal cestodes in wild goslings was 100% but their abundance varied among years (from 28.9 ± 2.7 to 175.2 ± 49.7 (mean ± SE) cestodes per host) and individuals. Captive goslings treated with anthelmintic drugs were free of parasites, whereas all control goslings were parasitized when sacrificed at 36 d, although cestode abundance in the latter group was much lower (4.2 ± 0.7) than in wild goslings. There was no difference in growth rates between treated and control captive goslings until they were 36 d of age. However, treated goslings spent more time feeding than control ones, which suggests an effect of cestodes on host behaviour. (Au)

I, J
Animal behaviour; Animal ecology; Animal growth; Animal health; Greater Snow Geese; Intestines; Necropsy; Parasites; Tapeworms

G0813
Bylot Island, Nunavut


Contaminant residues in seabird eggs from the Canadian Arctic. Part I. Temporal trends 1975-1998   /   Braune, B.M.   Donaldson, G.M.   Hobson, K.A.
(Environmental pollution, v.114, no. 1, Aug. 2001, p. 39-54, ill., 1 map)
(PCSP/PPCP contribution, no. 052-01)
References.
ASTIS record 50785.
Languages: English
Web: doi:10.1016/S0269-7491(00)00210-4
Libraries: ACU

Concentrations of total mercury, selenium and a suite of organochlorine compounds were measured in eggs of thick-billed murres (Uria lomvia), northern fulmars (Fulmarus glacialis) and black-legged kittiwakes (Rissa tridactyla) collected on Prince Leopold Island in Lancaster Sound, Nunavut, Canada, between 1975 and 1998. Mercury levels in thick-billed murre and northern fulmar eggs increased significantly during this period while selenium concentrations decreased significantly in northern fulmar eggs. Mercury and selenium concentrations in black-legged kittiwake eggs exhibited no significant temporal trends. Concentrations of Sigma PCB, Sigma DDT and total chlorobenzenes decreased over time for all three species and there was a shift in the PCB congener pattern as the hexachlorobiphenyl fraction of Sigma PCB increased and the lower chlorinated biphenyl fraction decreased. Total chlordane, dieldrin and mirex concentrations decreased in kittiwake eggs while no significant trends were observed for the other two species. Increases in Sigma HCH levels were detected in thick-billed murre eggs but not in northern fulmar and black-legged kittiwake eggs. Levels of the ß-HCH isomer, however, increased significantly in murres and fulmars. Stable-nitrogen isotope analyses (delta 15N) indicate that the temporal trends observed for contaminant concentrations in eggs were not the result of shifts in trophic level. Changing deposition patterns of xenobiotic compounds over the summer and winter ranges of these birds provide a likely explanation for differing exposures through time. (Au)

I, J
Animal food; Animal health; Animal migration; Animal physiology; Animal reproduction; Bioaccumulation; Biomagnification; Bird nesting; Carbon; Chlordanes; Chromatography; DDT; Dieldrin; Effects monitoring; Fulmars; HCB; HCH; Isotopes; Kittiwakes; Measurement; Mercury; Mirex; Nitrogen; Organochlorines; PCBs; Pollution; Selenium; Spectroscopy; Temporal variations; Thick-billed Murres; Toxicity; Trophic levels

G0813
Prince Leopold Island, Nunavut


Molt migration in relation to breeding success in Greater Snow Geese   /   Reed, E.T.   Bêty, J.   Mainguy, J.   Gauthier, G.   Giroux, J.-F.
(Arctic, v. 56, no. 1, Mar. 2003, p. 76-81)
(PCSP/PPCP contribution, no. 005-02)
References.
Two publications have PCSP/PPCP contribution number 005-02. The other one is ASTIS record 74045.
ASTIS record 51383.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic56-1-76.pdf
Web: doi:10.14430/arctic604
Libraries: ACU

We describe summer migratory movements by female greater snow geese (Chen caerulescens atlantica) breeding on Bylot Island, Nunavut. We followed 121 radio-collared females between 1997 and 2001 to determine the frequency and timing of their departure from the colony in relation to breeding status, nesting success, and molting chronology. We found that 90% (n = 51) of non-breeders (no nest found) and 97% (n = 29) of failed nesters (nest destroyed or abandoned before hatch) departed the island before molting. The few non-breeders that remained on Bylot Island all summer molted earlier than adults with young, and they appeared to initiate the fall migration before breeding geese. In contrast, only 2% of successful nesters (n = 41) left Bylot Island to molt, and those that did presumably had lost their offspring in the early stages of brood rearing. Thus, the occurrence of a molt migration in greater snow geese appears to be strongly dependent on reproductive status and nesting success. The area used by molt migrants and their habitat requirements during molt remain unknown. We suggest that the paucity of predator-safe areas (such as large water bodies) on Bylot Island may be an important factor that drives the geese to molt elsewhere. (Au)

I, J, F
Aerial surveys; Animal behaviour; Animal food; Animal live-capture; Animal migration; Animal mortality; Animal population; Animal reproduction; Animal tagging; Biological clocks; Bird nesting; Greater Snow Geese; Lakes; Plumage; Predation; Radio tracking of animals; Seasonal variations; Telemetry; Wildlife habitat

G0813
Bylot Island, Nunavut; Erichsen Lake, Nunavut; Quartz Lake, Nunavut


Kitigaaryuit Archaeological Inventory and Oral Traditions Project - 2001   /   Hart, E.   Inuvialuit Social Development Program [Sponsor]   Inuvialuit Cultural Resource Centre [Sponsor]
Inuvik, N.W.T. : Inuvialuit Social Development Program, 2002.
63 leaves : ill., maps ; 28 cm.
(PCSP/PPCP contribution, no. 005-02)
Appendices.
References.
Two publications have PCSP/PPCP contribution number 005-02. The other one is ASTIS record 51383.
Partial contents: Appendix A: New cultural remains found at NiTr-2 in the North Graveyard - Appendix B: Kitigaaryuit coastal stability, baseline assessment / Steven Solomon.
Report date: July 2002.
ASTIS record 74046 describes Appendix B of this report.
ASTIS record 74045.
Languages: English

... This report provides an overview of research conducted at Kitigaaryuit National Historic Site in August of 2001 by the Inuvialuit Social Development Program (ISDP). This consisted of an archaeological project to obtain coordinates for a small number of cultural remains. Oral traditions interviews were done in learn about the use of some of the cultural remains and obtain first-hand accounts of what life was like at Kitigaaryuit. The bulk of the research focussed on geological assessments needed to determine the rate of coastal erosion at the site. This brings us nearer to the end of the first phase of research at Kitigaaryuit which was designed to determine the nature and extent of cultural remains, the area the site encompasses, and the threats to it from various cultural and natural processes. All of this is required for the development of a management plan for this national historic site. ... Five days were spent at Kitigaaryuit from the evening of August 17 to the afternoon of August 22. ... The objectives of the archaeological research in 2001 were to document the locations of cultural remains in the North Graveyard in the area east of the bay called Imaaqtualuk. ... To obtain GPS readings in 2001 we located the cultural remains by going directly to those I knew the location of, and also conducted a survey. ... When new cultural remains were found we wrote descriptions of them, photographed them and took a GPS reading. ... Between the work done in 2000 and 2001, 25 cultural remains were found in the North Graveyard, east of Imaaqtualuk. Eight of these are new and consisted of one human remain, one grave log and six graves .... Of the new graves found, a cluster of five were outside the area examined in previous years. This necessitates expanding the proposed boundary for Kitigaaryuit National Historic Site further east. ... The only standing historic structure at Kitigaaryuit is the log cabin ruin. Its condition has worsened since this project began in 1996. ... Table 1 shows the 485 cultural remains documented at Kitigaaryuit during field projects in 1996, 1997, 2000 and 2001. ... Interviews were to be conducted with elders who used the reindeer corral at Kitigaaryuit so that we could learn why this was a good place for reindeer and for having a corral. We also wanted to learn about the herders' experiences working in this area. We hoped to learn about the use of the whaling camp from Bill and Lucy Cockney who built it and from Deva and Jimmy Gordon who had use it in latter years. I also hoped to develop a picture of what life was like there and why it was a good place to live. ... I am very grateful to the five elders who participated in this project. They are Laura Raymond, Annie and Adam Emaghok, Noah Felix and Otto Binder. ... Elders were interviewed using an audio recorder. ... Five audio tapes were produced. One was translated by Beverly Amos of Inuvik. The other tapes were transcribed in English by Laura Ettagiak Orchard of Yellowknife. ... The transcripts are bound separately under the title "Kitigaaryuit Archaeological Inventory and Mapping Project - 2001: Interview Transcripts". The tapes and transcripts will be stored at the Inuvialuit Cultural Resource Centre. ... A summary of the results of the interviews is provided below with the exception of one interview done with Laura Raymond. ... The majority of the fieldwork done during the 2001 project consisted of geological assessments of coastal stability by Steven Solomon of the Geological Survey of Canada (GSC). His report is presented in Appendix B [described by ASTIS record 74046]. ... One of the more surprising finds was that much of the erosion takes place during spring flooding of the Mackenzie River rather than from northwesterly storms over the ocean that result in waves pounding the coastline. ... Our next task is to present the results of our research at an upcoming workshop on Kitigaaryuit. This is the second workshop that will be attended by e lders and other who have a keen interest in the site. ... (Au)

U, V, T, A, I, N, R, H
Archaeology; Artifacts; Boundaries; Buildings; Coast changes; Communication; Databases; Effects monitoring; Elders; Erosion; Floods; Geographic information systems; Geographical positioning systems; Graves; Heritage sites; History; Inuit; Inuit archaeology; Inuit languages; Location; Mapping; Maps; Oral history; Public education campaigns; Reindeer husbandry; Shorelines; Shorelines; Social surveys; Sound recordings; Spatial distribution; Thaw flow slides; Thermokarst; Topography; Traditional knowledge

G0812
East Channel (Mackenzie River) region, N.W.T.; East Channel (Mackenzie River), N.W.T.; Kittigazuit Bay region, N.W.T.; Kittigazuit region, N.W.T.


Methanogenesis in Eocene Arctic soils inferred from delta 13C of tree fossil carbonates   /   Jahren, A.H.   LePage, B.A.   Werts, S.P.
(Palaeogeography, palaeoclimatology, palaeoecology, v.214, no. 4, 25 Nov. 2004, p. 347-358, ill., maps)
(PCSP/PPCP contribution, no. 008-02)
References.
ASTIS record 55801.
Languages: English
Web: doi:10.1016/j.palaeo.2004.07.030
Libraries: ACU

We report on the carbon and oxygen stable isotope composition of fossil tree material collected at the White Mountain locality of the Buchanan Lake Formation on Axel Heiberg Island in the High Arctic of Canada. The fossils are Middle Eocene in age and have been permineralized with carbonate. Microscopic examination of fossils revealed them to be the remains of Metasequoia stems, composed of secondary carbonate (calcite) and original wood intermingled at the cellular level. Because the specimens show little compression, crushing, or tissue degradation, we believe that carbonate permineralization occurred soon after burial, and therefore provides insight into Eocene carbon cycling at the locality. The carbon isotope signature of the carbonate suggests that methanogenesis resulted in a 13C-enriched CO2 pool that equilibrated with soil water and gave rise to unusually 13C-enriched CaCO3. Tree fossil carbonate exhibited strikingly high delta 13C values (+4.0 to +7.4‰) compared to published Phanerozoic pedogenic carbonate delta 13C values. These delta 13C values, in conjunction with fractionation factors (alpha) previously determined for carbonate precipitation and methanogenic pathways, indicate an Eocene soil CO2 pool containing 80-95% CO2 produced as a by-product of acetate-fermentation methanogenesis. Because methane in the atmosphere is a powerful greenhouse gas, we suggest that methane emissions from Axel Heiberg soils contributed to the relatively warm Arctic climate during the Middle Eocene. (Au)

B, H, C, I, H, E
Atmospheric chemistry; Biochemistry; Biodegradation; Biomass; Calcite; Carbon; Carbon dioxide; Corals; Eocene epoch; Fossil forests; Interstitial water; Isotopes; Leaves; Mass spectrometry; Measurement; Methane; Oxygen-18; Palaeobotany; Palaeoclimatology; Palaeopedology; Permian period; Plant respiration; Primary production (Biology); Soil chemistry; Soil microorganisms; Soil moisture; X-rays

G0813
Axel Heiberg Island, Nunavut; Geodetic Hills, Nunavut; White Mountain, Nunavut


Tundra lakes and permafrost, Richards Island, western Arctic coast, Canada   /   Burn, C.R.
(Canadian journal of earth sciences, v. 39, no. 8, Aug. 2002, p.1281-1298, ill., maps)
(PCSP/PPCP contribution, no. 011-02)
References.
ASTIS record 51919.
Languages: English
Web: doi:10.1139/e02-035
Libraries: ACU

Lakes, of average size 33 ha, occupy a quarter of the surface area of Richards Island, Northwest Territories. Most of the lakes have a central pool deeper than the thickness of winter ice, and many have prominent, shallow, littoral terraces. The relatively warm lake bottoms cause considerable disturbance to the surrounding continuous permafrost. Water and lake-bottom temperatures, the configuration of permafrost, and active-layer thickness were measured at a tundra lake between 1992 and 1997. The lake is oval, 1.6 km long, 800 m wide, and as deep as 13 m. Sandy terraces, covered by less than 1 m of water, extend over 100 m from the shore. The terraces are underlain by permafrost, which terminates almost vertically at their edge. The annual mean temperature measured at lake bottom in the central pool ranged between 1.5°C and 4.8°C, depending on depth, and between -0.2°C and -5°C on the terraces, due to differences in snow cover and proximity to the central pool. In consequence, the temperature of permafrost at 7 m depth in the terraces also varied, from -2°C near shore to -5°C in mid-terrace. The active layer in the terraces was uniformly 1.4 m deep. Geothermal modelling of talik configuration indicates that there is no permafrost beneath the central pool of the lake. The modelling indicates that, under equilibrium conditions, about one quarter of the lakes on Richards Island have taliks that penetrate permafrost, and at least 10-15% of the island is underlain by talik. Short-term climatic changes predicted for the region imply a small increase in summer lake-water temperature and an extension of the open-water season, accompanied by thicker snow cover in winter. Following such changes, with longer freeze-up and warmer terrace temperatures in winter, permafrost may not be sustainable in the lake terraces. (Au)

C, F, G, E
Active layer; Bathymetry; Bottom sediments; Climate change; Effects of climate on permafrost; Frozen ground; Lake ice; Lakes; Permafrost beneath lakes; Soil temperature; Temperature; Thermal regimes

G0812
Richards Island, N.W.T.


Paleolimnological evidence from diatoms for recent environmental changes in 50 lakes across Canadian Arctic treeline   /   Rühland, K.   Priesnitz, A.   Smol, J.P.
(Arctic, antarctic, and alpine research, v. 35, no. 1, Feb. 2003, p. 110-123, ill., maps)
(PCSP/PPCP contribution, no. 012-02)
References.
ASTIS record 55588.
Languages: English
Web: doi:10.1657/1523-0430(2003)035[0110:PEFDFR]2.0.CO;2
Libraries: ACU

Changes in diatom assemblage composition since preindustrial times were analyzed in a landscape paleolimnological study of 50 lakes and also in a more detailed analysis of a dated sediment core from Slipper Lake in the Canadian central arctic treeline region. The most apparent taxonomic shift was toward a higher relative abundance of the planktonic Cyclotella stelligera complex and a lower relative abundance of benthic Fragilaria taxa (F. pinnata, F. construens var. venter, F. construens, and F. brevistriata) in the modern versus the older sediments. Diatom assemblage composition in Slipper Lake recorded a marked change in the top 5.0 cm (ca. mid-1800s) of the core with a clear shift to a more planktonic diatom assemblage characterized by higher percentages of the Cyclotella stelligera complex. Possible causative factors, such as recent anthropogenic acidification, nutrient enrichment, or atmospheric deposition of contaminants, do not appear sufficient to explain these species changes. Instead, these recent assemblage shifts are consistent with limnological changes occurring with climatic warming, such as a shorter duration of ice cover, a longer growing season, and/or stronger thermal stratification patterns. (Au)

E, B, H, J, C, F
Acid rain; Air pollution; Benthos; Bottom sediments; Chemical properties; Climate change; Cores; Diatoms; Effects of climate on plants; Fresh-water ecology; Fresh-water flora; Growing season; Lake ice; Lake stratification; Lakes; Mass spectrometry; Meteorology; Palaeobotany; Palaeoecology; Permafrost; Plankton; Plant distribution; Plant taxonomy; Plants (Biology); Pollution; Precipitation (Meteorology); Radiocarbon dating; Sedimentation; Soils; Taiga ecology; Temporal variations; Treeline; Tundra ecology; Water pH

G0812, G0813
Slipper Lake, N.W.T.; Thelon Game Sanctuary, N.W.T./Nunavut; Yellowknife region, N.W.T.


Multi-island seasonal home range use by two Peary caribou, Canadian High Arctic islands, Nunavut, 1993-94   /   Miller, F.L.
(Arctic, v. 55, no. 2, June 2002, p. 133-142, maps)
(PCSP/PPCP contribution, no. 013-02)
References.
ASTIS record 49615.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic55-2-133.pdf
Web: doi:10.14430/arctic697
Libraries: ACU

A female and a male Peary caribou (Rangifer tarandus pearyi) were captured on 29 July 1993 on Massey Island, south-central Queen Elizabeth Islands, Nunavut, Canada. Each was fitted with a satellite telemetry neck-collar, released, and tracked by satellite from 1 August 1993 to 31 July 1994. The female caribou used five islands and the male caribou used six islands as seasonal and (collectively) as annual home range. They used five of the six islands (Vanier, Cameron, Alexander, Massey, and Marc) both during the same time periods and at different times. Bathurst Island was used only briefly and only by the male. The male and female occupied the same island at the same time during 54% of the 1993-94 annual cycle. Their seven periods of common occupancy ranged in length from 5 to 88 consecutive days. During the study period, the female moved from one island to another on 11 separate occasions, and the male, on 16 occasions. The female's periods of residence on each island ranged in length from 4 to 95 consecutive days, and the male's from 2 to 169 consecutive days. Their seasonal and annual range-use patterns suggest a degree of flexibility and adaptability to a variable and taxing environment and indicate the important role that relatively small islands play in the ecology of Peary caribou. (Au)

I, J
Animal behaviour; Animal distribution; Animal ecology; Animal live-capture; Animal migration; Caribou; Gender differences; Islands; Radio tracking of animals

G0813
Canadian Arctic Islands; Massey Island, Nunavut


Periphytic diatom assemblages from ultra-oligotrophic and UV transparent lakes and ponds on Victoria Island and comparisons with other diatom surveys in the Canadian Arctic   /   Michelutti, N.   Holtham, A.J.   Douglas, M.S.V.   Smol, J.P.
(Journal of phycology, v. 39, no. 3, June 2003, p. 465-480, ill., map)
(PCSP/PPCP contribution, no. 014-02)
References.
ASTIS record 55439.
Languages: English
Web: doi:10.1046/j.1529-8817.2003.02153.x
Libraries: ACU

Periphytic diatoms are potentially powerful indicators of environmental change in climatically sensitive high latitude regions. However, only a few studies have examined their taxonomic and ecological characteristics. We identified and enumerated diatom assemblages from sediment, rock, and moss habitats in 34 ultra-oligotrophic and highly transparent lakes and ponds on Victoria Island, Arctic Canada. The similar limnological characteristics of the sites allowed us to examine the influence of habitat, independent of water chemistry, on the diatom assemblages. As is typical in shallow arctic water bodies, benthic taxa, including species of Achnanthes, Caloneis, Cymbella, Navicula, and Nitzschia, were most widely represented. Minor gradients in our measured environmental variables did not significantly explain any variance in diatom species, but there were marked differences in diatom assemblages among sites. Pond ephemerality seems to explain some diatom variation, because aerophilic taxa such as Achnanthes kryophila Petersen and A. marginulata Grunow were dominant in shallow sites that had undergone appreciable reductions in volume. We identified several taxa that exhibited strong habitat preferences to sediment, moss, or rock substrates and also found significant differences (P < 0.01) in diatom composition among the three habitats. In comparisons with three similar diatom surveys extending over 1200 km of latitude, we determined that surface sediment assemblages differed significantly (P < 0.001) among all regions examined. Diatom species diversity was inversely related to latitude, a result likely explained by differences in the lengths of growing seasons. These data contribute important ecological information on diatom assemblages in arctic regions and will aid in the interpretation of environmental changes in biomonitoring and paleolimnological studies. (Au)

H, F, B, E, J
Algae; Biomass; Bottom sediments; Carbon; Chemical properties; Climate change; Cores; Diatoms; Effects monitoring; Fresh-water ecology; Lakes; Mosses; Palaeoclimatology; Phosphorus; Plant distribution; Plant growth; Plant taxonomy; Rocks; Tundra ponds; Wildlife habitat

G0813
Bathurst Inlet region, Nunavut; Bathurst Island, Nunavut; Ellesmere Island, Nunavut; Herschel, Cape, Nunavut; Victoria Island, N.W.T./Nunavut


Colored dissolved organic matter and dissolved organic carbon exclusion from lake ice : implications for irradiance transmission and carbon cycling   /   Belzile, C.   Gibson, J.A.E.   Vincent, W.F.
(Limnology and oceanography, v. 47, no. 5, Sept. 2002, p.1283-1293, ill.)
(PCSP/PPCP contribution, no. 015-02)
References.
ASTIS record 51947.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/165.pdf
Web: doi:10.4319/lo.2002.47.5.1283
Libraries: ACU

Thick ice cover is a feature of cold-temperate, polar, and alpine lakes and rivers throughout much of the year. Our observations from Canadian lakes and rivers across the latitudinal gradient 46-80°N show that their overlying ice contains low concentrations of dissolved organic carbon (DOC) and colored dissolved organic matter (CDOM) relative to the underlying waters. The CDOM exclusion factor (water/ice) ranged from 1.4 to 114 and was typically greater than twice the exclusion factor for inorganic solutes. Application of synchronous fluorescence analysis to lake ice samples and experimentally frozen lake water indicated that only less complex, lower molecular weight molecules were retained within the ice. Consistent with this analysis, DOC-specific absorption showed that the DOC in the ice was generally less colored than that in the underlying waters. The reduced CDOM absorption within the ice allowed relatively high ultraviolet (UV) transmission despite the elevated scattering within the ice and resulted in UV diffuse attenuation coefficients up to eight times lower in the ice than in the underlying waters. This relatively low attenuation by the ice would cause organisms trapped near the surface by inverse stratification to experience high UV exposure prior to ice breakup. The ice exclusion effect gives rise to a concentrated zone of CDOM and DOC that is likely to favor heterotrophic and mixotrophic processes and influence biogeochemical interactions. (Au)

G, F, J, E
Albedo; Algae; Biological productivity; Carbon cycling; Chemical properties; Climate change; Colored dissolved organic matter; Cores; Dissolved organic carbon; Electrical properties; Fluorometry; Formation; Fresh-water ecology; Impurities; Lake ice; Lakes; Measurement; Microbial ecology; Optical properties; Physical properties; River ice; Rivers; Surface properties; Thickness; Ultraviolet radiation

G0813, G0826
Baleine, Grande rivière de la, Québec; Char Lake, Nunavut; Kachishayoot, Lac, Québec; Québec; Romulus Lake, Nunavut; Saint-Jean, Lac, Québec


A re-evaluation of species limits in Canadian Arctic Island Puccinellia (Poaceae) : resolving key characters   /   Consaul, L.L.   Gillespie, L.J.
(Canadian journal of botany, v. 79, no. 8, Aug. 2001, p. 927-956, ill.)
(PCSP/PPCP contribution, no. 018-02)
Appendix.
References.
The PCSP/PPCP contribution number is incorrectly given as 009-01 in the Acknowledgments of this article. The correct number is 018-02.
ASTIS record 50509.
Languages: English
Web: doi:10.1139/cjb-79-8-927
Libraries: ACU

This study examined morphological variation for species of Puccinellia that have traditionally posed problems of identification in the Canadian Arctic Archipelago. The first part of the study involved a re-examination of several characters that were difficult to define or describe. Microscopic examination of lemma and glume apices revealed that the characters "erose-ciliolate" lemma and glume apex margins are more accurately divided into two characters: degree to which they are erose, and presence of trichomes. These trichomes consist of acute or acuminate cells that protrude 15-35 µm from the margin, sometimes with a spinulose tip up to 10 µm long. The term "thickened pedicel" is clarified to mean thickened below the apex in relation to the apex. The second part of the study involved preliminary morphometric analyses on the above-mentioned revised characters, plus other characters previously shown to have low plasticity in this genus, for 10 recognized species that are difficult to distinguish. Many species or species complexes resolved to a small degree, but no taxa formed distinct groups. Correlations among many characters were low, accounting for a low percentage of variation explained by the first few principal components. Hypotheses of species boundaries and a preliminary revised key to species and species groups, incorporating findings from this study, are presented. (Au)

H
Grasses; Plant anatomy; Plant collections; Plant distribution; Plant growth; Plant taxonomy

G0813
Canadian Arctic Islands; Nunavut


Fall movements of belugas (Delphinapterus leucas) with satellite-linked transmitters in Lancaster Sound, Jones Sound, and northern Baffin Bay   /   Richard, P.R.   Heide-Jørgensen, M.P.   St. Aubin, D.
(Arctic, v. 51, no. 1, Mar. 1998, p. 5-16, ill., maps)
(PCSP/PPCP contribution, no. 022-02)
References.
ASTIS record 42383.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic51-1-5.pdf
Web: doi:10.14430/arctic1040
Libraries: ACU

Six adult belugas, Delphinapterus leucas, (2 males, 4 females) were instrumented with satellite-linked transmitters in Croker Bay, southeastern Devon Island in the Canadian High Arctic in mid-September 1995. Some days, the animals remained close to shore along the southeastern and eastern shoreline of Devon Island, presumably foraging for arctic cod (Boreogadus saida) and other prey. They spent the rest of the time in the deep waters of Lady Ann Strait, eastern Jones Sound, and the waters southeast of Coburg Island, presumably feeding on deepwater prey. Only males went farther north in water off southeastern Ellesmere Island, the belugas' swimming speeds decreased in the later part of the study period. Their last transmissions came from the North Water, an area where belugas are known to winter. Results of this study were not sufficient to determine the extent of movement of belugas between the eastern Canadian Arctic and Greenland. (Au)

I
Animal behaviour; Animal distribution; Animal food; Animal migration; Animal population; Arctic cod; Beluga whales; Radio tracking of animals; Satellite communications

G0815, G09
Coburg Island waters, Nunavut; Croker Bay, Nunavut; Jones Sound, Nunavut; Lady Ann Strait, Nunavut; Lancaster Sound, Nunavut; North Water Polynya, Baffin Bay


'Drunken forest' and near-surface ground ice in Mackenzie Delta, Northwest Territories, Canada   /   Kokelj, S.V.   Burn, C.R.
In: Permafrost : proceedings of the 8th International Conference on Permafrost, Zurich, Switzerland, 21-25 July 2003 / Edited by M. Phillips, S.M. Springman, L.U. Arenson. - Rotterdam : A.A. Balkema ; London : Momenta, 2003, p. 567-571, maps
(PCSP/PPCP contribution, no. 023-02)
References.
Indexed from the Web.
ASTIS record 68700.
Languages: English
Web: http://tinyurl.com/465g2fo
Libraries: ACU

In Mackenzie River delta, emergent point bars are colonized by straight white spruce trees in association with alder and willow bushes. On older surfaces, colonized by mosses, the trees are characteristically leaning. In white spruce communities above the level of regular flooding, the trees are stunted and tilted. Tree lean and ground ice content were measured at 18 sites in the delta. There is a clear, positive association between the ice content of near-surface permafrost in drill core samples and the extent of tree lean at the sites. The relation between near-surface ground ice and tree lean suggests that aggradation and/or degradation of ice-rich permafrost can result in the tilting of spruce trees, and that forest structure may be used to predict near-surface ground ice content in Mackenzie Delta. (Au)

H, C, J
Active layer; Cores; Floods; Ground ice; Measurement; Moisture content of permafrost; Permafrost; Plant anatomy; Plant growth; Plant succession; Plant-soil relationships; Sedimentation; Taiga ecology; Unfrozen water content of frozen ground; White spruces

G0812
Mackenzie Delta, N.W.T.


Ecology and spatial distributions of surface-sediment diatoms from 77 lakes in the Subarctic Canadian treeline region   /   Rühland, K.M.   Smol, J.P.   Pienitz, R.
(Canadian journal of botany, v. 81, no. 1, Jan. 2003, p. 57-73, ill., maps)
(PCSP/PPCP contribution, no. 024-02)
References.
ASTIS record 54654.
Languages: English
Web: doi:10.1139/b03-005
Libraries: ACU

Diatom ecology and species compositional patterns across current arctic treeline can provide important paleoecological information associated with climatic and environmental change. In this paper we examine the relationships between measured environmental variables and modern diatom assemblage composition from 77 lakes across the treeline ecozones of the Central Canadian Arctic. The weighted-average optima for selected environmental variables were calculated for 74 of the most common diatoms, and photographic plates of these taxa are included. Our results indicated that both forest-tundra and arctic tundra lakes differed significantly in diatom assemblage composition from boreal forest lakes. In general, planktonic diatom taxa (e.g., Cyclotella species) were more common in forested lakes, which may be due to ecological conditions related to climate. Small, benthic, alkaliphilic Fragilaria taxa reached their highest abundances in forested lakes, likely because of the more alkaline nature of these lakes. Arctic tundra lakes were characterized by higher abundances of circumneutral to acidophilic taxa. Heavily silicified Aulacoseira taxa (e.g., Aulacoseira lirata, Aulacoseira perglabra) were more common in deeper tundra lakes, likely because of the less alkaline nature of these lakes and greater wind-induced turbulence in this zone. These trends provide important information on the variability of aquatic ecosystems across this climatically sensitive vegetational gradient. (Au)

B, F, H, E, J
Climate change; Diatoms; Fresh-water biology; Fresh-water ecology; Lakes; Palaeoclimatology; Palaeoecology; Plankton; Plant distribution; Plant taxonomy; Suspended solids; Taiga ecology; Treeline; Tundra ponds; Water pH

G0812, G0813
Bathurst Inlet region, Nunavut; Thelon Game Sanctuary, N.W.T./Nunavut; Yellowknife region, N.W.T.


Breeding biology of brant on Banks Island, Northwest Territories, Canada   /   Cotter, R.C.   Hines, J.E.
(Arctic, v. 54, no. 4, Dec. 2001, p. 357-366, maps)
(PCSP/PPCP contribution, no. 027-02)
References.
ASTIS record 48902.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic54-4-357.pdf
Web: doi:10.14430/arctic793
Libraries: ACU

The numbers of brant (Branta bernicla) in the Pacific Flyway are relatively small compared to other populations of arctic geese and have declined from historic levels. Little information is available on brant from Banks Island, although the size of the island and its location in the western Canadian Arctic make it a potentially important nesting area for this species. In 1992-93, we documented the distribution of nesting brant on the southern half of Banks Island through aerial surveys and carried out ground studies at the colonies to document nesting chronology and reproductive parameters. Ten colonies were found in 1992 (n = 159 nests) and 42 colonies (including seven colonies that had been active in 1992) and five solitary nests were found in 1993 (n = 514 nests). Two-thirds (67%) of the nesting locations supported 10 or fewer nests. Most colonies (36 of 45) were located on small islands (mean = 248 m²) in inland lakes or large ponds, and the remaining colonies (n = 9) were located on the mainland near active snowy owl (Nyctea scandiaca) nests. In 1993, when June temperatures were milder and snow melted sooner than in 1992, mean date of clutch initiation was significantly earlier (12 June vs. 20 June in 1992; p < 0.001) and mean clutch size was significantly larger (3.8 vs. 3.5 in 1992; p = 0.02). An index of productivity for the 21 414 km² area surveyed in both years was much higher in 1993 (1339 young) than in the very late spring of 1992 (347 young). The number of adult brant on the survey area was similar in both years, and the lower productivity in 1992 was due primarily to fewer pairs' nesting that year. Smaller clutch size and lower nesting success may also have lowered productivity in 1992, but their effects appeared to be secondary. No correlation was found between colony size and clutch size, mean number of goslings hatched, or the percentage of nests that proved successful. (Au)

I
Animal distribution; Animal population; Biological productivity; Bird nesting; Brant; Glaucous Gulls; Sabine's Gulls; Snowy Owls

G0812
Banks Island, N.W.T.


Calf production, calf survival, and recruitment of muskoxen on Banks Island during a period of changing population density from 1986-99   /   Larter, N.C.   Nagy, J.A.
(Arctic, v. 54, no. 4, Dec. 2001, p. 394-406, ill., 2 maps)
(PCSP/PPCP contribution, no. 028-02)
References.
ASTIS record 48905.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic54-4-394.pdf
Web: doi:10.14430/arctic796
Libraries: ACU

Population estimates for muskoxen (Ovibos moschatus) (age > 1 year) on Banks Island increased from 29 168 (SE 2104) in 1985 to a peak of 64 608 (SE 2009) in 1994 and then declined to 45 833 (SE 1938) in 1998. From 1986 to 1999, annual sex and age classification surveys of muskoxen were conducted during summer. We estimated calf production (number of calves per 100 females aged 2 years or more), calf survival, and recruitment (number of yearlings per 100 females aged 2 years or more). Calf production ranged from 31.3 to 56.3 and was similar between periods of increasing and decreasing density (mean = 42.3 vs. 40.8). Calf survival ranged from 23% to 83% and was generally higher while density was increasing than during its decline (mean = 60 vs. 45). Survival at a given density was lower following the 1994 peak in density. Recruitment ranged from 10.0 to 41.7 and was higher (p = 0.06) during the period of increasing density than during the decline (mean = 28.0 vs. 17.2). Calf survival and recruitment were lowest following two consecutive severe winters, but animal density explained more of the variation in survival and recruitment than did late-winter snow depth. There was a positive relationship between the proportion of sedge (Carex spp., Eriophorum scheuchzeri) in the summer diet and calf survival and recruitment. Patterns of calf survival and recruitment plotted against density were consistent with those modelling a density-dependent relationship. Our results suggest that severe weather alone cannot explain the fluctuations in the population dynamics of Banks Island muskoxen and that underlying density-dependent responses acting upon calf survival and recruitment offer an alternative explanation. (Au)

I, F, J
Animal food; Animal population; Animal waste products; Grazing; Muskoxen; Sedges; Snow; Willows; Winter ecology

G0812
Banks Island, N.W.T.


Habitat requirements of White-winged and Surf Scoters in the Mackenzie Delta region, Northwest Territories   /   Haszard, S.L.
(Arctic, v. 54, no. 4, Dec. 2001, p. 472-474, ill.)
(PCSP/PPCP contribution, no. 029-02)
References.
ASTIS record 48912.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic54-4-472.pdf
Web: doi:10.14430/arctic803
Libraries: ACU

... My thesis work focuses on learning more about the habitat requirements of white-winged and surf scoters in the Mackenzie Delta region. ... This summer, I conducted helicopter surveys of 220 wetlands in 31 randomly selected plots. Half of the plots were in the Delta, and half were in the upland habitat. Each wetland was surveyed twice in June for breeding pairs and twice in early August for broods. Wetlands were then classified as used or not used by pairs and broods of both species. In mid-August, I revisited a subset for used and non-used wetlands to collect water samples and data concerning characteristics of each wetland and its surrounding upland habitat. Initial results indicate that white-winged scoter pairs are more abundant than those of surf scoters in both Delta and upland regions. Pairs of both species occupy upland lakes more frequently than Delta lakes and seem to e more abundant on medium and large wetlands than on small wetlands. Although we observed 394 pairs of white-winged scoters and 68 pairs of surf scoters during the two breeding pair surveys, we observed only 68 white-winged scoter broods and 20 surf scoter broods. The broods were distributed approximately equally between Delta and upland lakes. I am currently compiling and analyzing data to verify these initial impressions and evaluate a habitat selection pattern. I will conduct a second field season next summer to compare predicted scoter distributions (based on results from 2001 data) and observed scoter distributions from independent surveys of new lakes in new plots. (Au)

I
Aerial surveys; Animal distribution; Animal population; Bird nesting; Scoters; Wetlands; Wildlife habitat

G0812
Mackenzie Delta, N.W.T.


Intra-annual and intra-seasonal flow dynamics of a High Arctic polythermal valley glacier   /   Bingham, R.G.   Nienow, P.W.   Sharp, M.J.
(Papers from the International Symposium on Physical and Mechanical Processes in Ice in Relation to Glacier and Ice-sheet Modelling, held in Chamonix, France, 25-30 August 2002 / Edited by P. Duval et al.. Annals of glaciology, v. 37, 2003, p. 181-188, ill., maps)
(PCSP/PPCP contribution, no. 032-02)
References.
ASTIS record 55572.
Languages: English
Web: doi:10.3189/172756403781815762
Libraries: ACU

Measurements of surface dynamics on polythermal John Evans Glacier, Nunavut, Canada, over two winter periods and every 7-10 days throughout two melt seasons (June- July 2000, 2001) provide new insight into spatio-temporal patterns of High Arctic glacier dynamics. In the lower ablation zone, mean annual surface velocities are 10-21 m/a, but peak velocities up to 50% higher are attained during late June/early July. In the upper ablation zone and lower accumulation zone, mean annual surface velocities are typically 10-18 m/a, and peak velocities up to 40% higher occur during late July. In the upper accumulation zone, mean annual surface velocities are 2-9 m/a, and motion in mid- to late July exceeds this by up to 10%. Rapid drainage of ponded supraglacial water in the upper ablation zone to an initially distributed subglacial drainage system in mid-June may force excess surface motion in the warm-based lower glacier. The data indicate that the duration of the velocity response may be related to the rate of channelization of the basal drainage, and the velocity response may be transmitted up-glacier by longitudinal coupling. An increase in surface velocities in the middle glacier in late July occurs in conjunction with the opening of two further moulins in the accumulation zone. (Au)

F, E
Ablation; Crevasses; Detection; Drainage; Dyeing; Effects of climate on ice; Flow; Glacial melt waters; Glacier lakes; Glaciers; Hydrology; Radar; Runoff; Seasonal variations; Spatial distribution; Structural geology; Temperature; Temporal variations; Velocity

G0813
John Evans Glacier, Nunavut


Patterns of distribution and abundance of Greater Snow Geese on Bylot Island, Nunavut, Canada 1983-1998   /   Reed, A.   Hughes, R.J.   Boyd, H.
(Wildfowl, no. 53, 2002, p. 53-65, ill., maps)
(PCSP/PPCP contribution, no. 033-02)
Indexed a PDF file from the Web.
ASTIS record 79344.
Languages: English
Web: http://wildfowl.wwt.org.uk/index.php/wildfowl/article/download/1120/1120

To monitor the numbers and distribution of Greater Snow Geese at the largest breeding colony in the eastern Canadian High Arctic, surveys were conducted on Bylot Island at five year intervals from 1983 to 1998. The surveys were conducted during the brood-rearing period using a stratified sampling procedure and aerial photography. The total number of adult geese increased from 25,500 (SE 2582) in 1983 to 69,500 [SE 8645) in 1993 (a year of exceptionally high breeding effort and breeding success) before dropping slightly in 1998. The number of goslings also increased from 26,500 (SE 2320) in 1983 to 86,500 (SE 8147) in 1993, and also dropped slightly in 1998. In years of high breeding success (1983 and 1993) the adult population on Bylot Island represented 14% of the entire world population of Greater Snow Geese. The adult population on Bylot Island between 1983 and 1998 showed an average annual rate of increase of 7%, similar to the 9% increase recorded for the entire population. Brood densities varied from a low of 0.8 broods/km² in the poorest quality habitats in 1983 to 29.9 broods/km² in the best habitats in 1993, but an increasing trend was evident in all habitat strata over the course of the study. A large proportion (63%) of the surface area of the colony accommodated only very low brood densities in 1983, but by 1993 the proportion occupied by such low densities had been reduced to 29%. It is concluded that the increase in goose numbers and the spread of higher brood densities over a larger portion of the colony are indications that the carrying capacity of the Island has not yet been reached. (Au)

I, J, N, R
Aerial photography; Animal distribution; Animal population; Arctic foxes; Effects monitoring; Environmental impacts; Environmental protection; Government regulations; Grazing; Greater Snow Geese; Hunting; Predation; Temporal variations; Wetlands; Wildlife habitat; Wildlife management

G0813, G0826
Bylot Island, Nunavut; Québec


Freshwater diatoms from the Canadian Arctic treeline and development of paleolimnological inference models   /   Rühland, K.M.   Smol, J.P.
(Journal of phycology, v. 38, no. 2, Apr. 2002, p. 249-264, ill., maps)
(PCSP/PPCP contribution, no. 037-02)
References.
ASTIS record 51948.
Languages: English
Web: doi:10.1046/j.1529-8817.2002.01129.x
Libraries: ACU

Relationships between surface sediment diatom assemblages and measured environmental variables from 77 lakes in the central Canadian arctic treeline region were examined using multivariate statistical methods. Lakes were distributed across the arctic treeline from boreal forest to arctic tundra ecozones, along steep climatic and environmental gradients. Forward selection in canonical correspondence analysis determined that dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), total nitrogen (TN), lake surface area, silica, lake-water depth, and iron explained significant portions of diatom species variation. Weighted-averaging (WA) regression and calibration techniques were used to develop inference models for DIC, DOC, and TN from the estimated optima of the diatom taxa to these environmental variables. Simple WA models with classical deshrinking produced models with the strongest predictive abilities for all three variables based on the bootstrapped root mean squared errors of prediction (RMSEP). WA partial least squares showed little improvement over the simpler WA models as judged by the jackknifed RMSEP. These models suggest that it is possible to infer trends in DIC, DOC, and TN from fossil diatom assemblages from suitably chosen lakes in the central Canadian arctic treeline region. (Au)

H, J, B, F, E
Bottom sediments; Carbon; Chemical properties; Climate change; Diatoms; Dissolved organic carbon; Lakes; Mathematical models; Measurement; Nitrogen; Palaeobotany; Palaeoclimatology; Palaeoecology; Plant distribution; Plant taxonomy; Taiga ecology; Treeline; Tundra ecology; Tundra ponds

G0812, G0813
Bathurst Inlet region, Nunavut; Thelon Game Sanctuary, N.W.T./Nunavut; Yellowknife region, N.W.T.


Early Tertiary Chamaecyparis Spach from Axel Heiberg Island, Canadian High Arctic   /   Kotyk, M.E.A.   Basinger, J.F.   McIver, E.E.
(Canadian journal of botany, v. 81, no. 2, Feb. 2003, p. 113-130, ill., maps)
(PCSP/PPCP contribution, no. 040-02)
References.
ASTIS record 54655.
Languages: English
Web: doi:10.1139/b03-007
Libraries: ACU

Exquisitely preserved fossil remains of Chamaecyparis Spach (Cupressaceae) have been recovered from Middle Eocene sediments of the Buchanan Lake Formation, Eureka Sound Group, of Axel Heiberg Island, Canadian Arctic Archipelago. Foliage consists of flattened, frondlike sprays considered typical for the genus. Leaves are decussate, scalelike, imbricate, appressed, and persistent. Seed cones are globose to subellipsoid, are borne on leafy peduncles, and bear 8-12 woody, peltate cone scales in a decussate arrangement. Seeds are two or more per scale, and winged. Within the genus, this fossil is most similar to extant Chamaecyparis pisifera (Siebold & Zucc.) Endl. of Japan, although the suite of features found in the fossil does not occur in any single living species of the genus. These fossil remains are assigned to a new species, Chomaecyparis eureka D Kotyk sp. nov. A review of the fossil record indicates that Chamaecyparis eureka is the oldest known member of the genus, as the Late Cretaceous taxon Chamaecyparis corpulenta (Bell) Mclver appears most closely related to Cupressus nootkatensis D. Don [= Chamaecyparis nootkatensis (D. Don) Spach], and should therefore be excluded from the genus Chamaecyparis. As revealed by the fossil assemblages of the Buchanan Lake deposits, Chamaecyparis was an uncommon constituent of lowland, swamp-forest communities growing at high paleolatitudes (about 78°N) during a period of global warmth prior to the onset of global climatic deterioration that led to Late Cenozoic glaciation. It was one of the few evergreen taxa in a largely deciduous broad-leaved and coniferous vegetation of early Tertiary regions in the far north. (Au)

B, H, J, E
Cedars; Conifers; Cretaceous period; Eocene epoch; Evolution (Biology); Fossil forests; Palaeobotany; Palaeoclimatology; Palaeoecology; Palynology; Plant anatomy; Plant taxonomy; Sediments (Geology); Seeds; Tertiary period

G0813
Axel Heiberg Island, Nunavut; Buchanan Lake region, Nunavut


Contaminant residues in seabird eggs from the Canadian Arctic. II. Spatial trends and evidence from stable isotopes for intercolony differences   /   Braune, B.M.   Donaldson, G.M.   Hobson, K.A.
(Environmental pollution, v.117, no. 1, Apr. 2002, p. 133-145, ill., maps)
(PCSP/PPCP contribution, no. 041-02)
References.
ASTIS record 50786.
Languages: English
Web: doi:10.1016/S0269-7491(01)00186-5
Libraries: ACU

Eggs of glaucous gulls (Larus hyperboreus), black-legged kittiwakes (Rissa tridactyla), thick-billed murres (Uria lomvia) and black guillemots (Cepphus grylle) were collected from several sites throughout the Canadian Arctic. Samples were analyzed for organochlorines as well as mercury and selenium. Glaucous gulls breeding at sites in the High Arctic showed higher levels of organochlorine contamination than those in the western Low Arctic. This was likely due to dietary differences among colonies as suggested by stable isotope data, although different overwintering areas may also play a role. Levels of Sigma PCB, Sigma DDT, Sigma CHLOR, Sigma CBz and dieldrin were significantly lower in thick-billed murres from Prince Leopold Island in the High Arctic compared with colonies in the eastern Low Arctic. This difference was likely due to the combined effects of different atmospheric deposition patterns in the High and Low Arctic and different overwintering areas since murres from Prince Leopold Island may winter farther north than murres from the other colonies sampled. Eggs from colonies at higher latitudes generally contained higher concentrations of mercury. The trophic and dietary differences/similarities suggested by stable-nitrogen and carbon isotope data in this study were useful in explaining the spatial patterns of contaminant concentrations observed among colonies of seabirds such as the glaucous gull and the black-legged kittiwake where variation in latitudinal atmospheric deposition patterns and different overwintering grounds did not appear to be confounding factors. (Au)

I, J
Animal food; Animal health; Animal migration; Animal reproduction; Bioaccumulation; Biomagnification; Bird nesting; Black Guillemots; Carbon; Chromatography; DDT; Dieldrin; Food chain; Fulmars; Glaucous Gulls; HCB; HCH; Isotopes; Kittiwakes; Measurement; Mercury; Mirex; Nitrogen; Organochlorines; PCBs; Pollution; Selenium; Spatial distribution; Spectroscopy; Temporal variations; Thick-billed Murres; Toxicity; Trophic levels

G0813, G0812
Anderson River Delta Migratory Bird Sanctuary, N.W.T.; Browne Island, Nunavut; Coats Island, Nunavut; Coburg Island, Nunavut; Digges Islands, Nunavut; Nuvuk Islands, Nunavut; Prince Leopold Island, Nunavut; Richardson River region, Nunavut; Walrus Island, Nunavut


Compass orientation and possible migration routes of passerine birds at High Arctic latitudes   /   Muheim, R.   Åkesson, S.   Alerstam, T.
(Oikos, v.103, no. 2, Nov. 2003, p. 341-349, ill., maps)
(PCSP/PPCP contribution, no. 004-03)
References.
ASTIS record 55441.
Languages: English
Web: doi:10.1034/j.1600-0706.2003.12122.x
Libraries: ACU

The use of celestial or geomagnetic orientation cues can lead migratory birds along different migration routes during the migratory journeys, e.g. great circle routes (approximate), geographic or magnetic loxodromes. Orientation cage experiments have indicated that migrating birds are capable of detecting magnetic compass information at high northern latitudes even at very steep angles of inclination. However, starting a migratory journey at high latitudes and following a constant magnetic course often leads towards the North Magnetic Pole, which means that the usefulness of magnetic compass orientation at high latitudes may be questioned. Here, we compare possible long-distance migration routes of three species of passerine migrants breeding at high northern latitudes. The initial directions were based on orientation cage experiments performed under clear skies and simulated overcast and from release experiments under natural overcast skies. For each species we simulated possible migration routes (geographic loxodrome, magnetic loxodrome and sun compass route) by extrapolating from the initial directions and assessing a fixed orientation according to different compass mechanisms in order to investigate what orientation cues the birds most likely use when migrating southward in autumn. Our calculations show that none of the compass mechanisms (assuming fixed orientation) can explain the migration routes followed by night-migrating birds from their high Neararctic breeding areas to the wintering sites further south. This demonstrates that orientation along the migratory routes of arctic birds (and possibly other birds as well) must be a complex process, involving different orientation mechanisms as well as changing compass courses. We propose that birds use a combination of several compass mechanisms during a migratory journey with each of them being of a greater or smaller importance in different parts of the journey, depending on environmental conditions. We discuss reasons why birds developed the capability to use magnetic compass information at high northern latitudes even though following these magnetic courses for any longer distance will lead them along totally wrong routes. Frequent changes and recalibrations of the magnetic compass direction during the migratory journey are suggested as a possible solution. (Au)

I, B
Animal behaviour; Animal distribution; Animal migration; Diurnal variations; Geomagnetism; Navigation; Passeriformes; Testing

G0812, G081, G03, G0813
Banks Island, N.W.T.; Canadian Arctic; Inuvik region, N.W.T.; Melville Island, N.W.T./Nunavut; North Pole; Resolute, Nunavut


Tilt of spruce trees near ice wedges, Mackenzie Delta, Northwest Territories, Canada   /   Kokelj, S.V.   Burn, C.R.
(Arctic, antarctic, and alpine research, v. 36, no. 4, Nov. 2004, p. 615-623, ill., maps)
(PCSP/PPCP contribution, no. 005-03)
References.
ASTIS record 57235.
Languages: English
Web: doi:10.1657/1523-0430(2004)036[0615:TOSTNI]2.0.CO;2
Libraries: ACU

Ice wedges are common in the Mackenzie Delta, although troughs may be filled by sediments and obscured by growth of vegetation. At four sites in eastern Mackenzie Delta, over 85% of the trees within 1 m of ice-wedge troughs leaned towards these troughs. The mean angle of lean was 12° from the vertical, with some trees leaning by more than 25°. The angle of tree tilt varied inversely with distance from the ice-wedge trough and most of the trees over 1 m from an adjacent trough leaned away from the ice-wedge. Trees near the troughs are susceptible to toppling because their root systems trail away from the troughs. Reaction-wood rings in cross-sectional disks from trees leaning towards troughs indicated that progressive tilting has been sustained for decades to centuries. Long-term rates of tree tilting are estimated to be between 0.1 and 0.4°/a. Progressive, unidirectional tilting may eventually destroy the spruce trees. In Mackenzie Delta, where forest fire is infrequent, earth movements associated with ice-wedge polygons may be one mechanism driving forest change in old-growth stands. (Au)

C, H
Biological sampling; Cores; Creep; Deformation; Frozen ground; Ice wedges; Logistics; Measurement; Movement; Plant growth; Plant-soil relationships; Roots; Size; Slopes; Soils; Thermal regimes; Trees; White spruces

G0812
East Channel (Mackenzie River) region, N.W.T.


Limnological characteristics of 22 lakes and ponds in the Haughton Crater region of Devon Island, Nunavut, Canadian High Arctic   /   Lim, D.S.S.   Douglas, M.S.V.
(Arctic, antarctic, and alpine research, v. 35, no. 4, Nov. 2003, p. 509-519, ill., maps)
(PCSP/PPCP contribution, no. 006-03)
References.
ASTIS record 53660.
Languages: English
Web: doi:10.1657/1523-0430(2003)035[0509:LCOLAP]2.0.CO;2
Libraries: ACU

The physical and chemical limnological characteristics of 22 lakes and ponds in the remote region of Haughton Impact Crater, Devon Island, Nunavut, Canada, were explored. Our overall goals were to gather baseline information for use in climate and environmental change monitoring programs in the High Arctic as well as to compare these observations to other limnological surveys conducted in high-latitude regions. Study sites were alkaline (pHmean = 8.3), ultraoligotrophic (TPUmean = 3.7 µg/L), and phosphorus limited. Major and minor ionic concentrations of most sites are comparable to other previously surveyed high arctic sites. Lakes and ponds in close contact with the impact-generated carbonate melt rocks associated with Haughton Crater were distinguished from the larger data set due to their elevated Mg2+, (SO4)2-, Ba2+, Sr2+, and SiO2 concentrations. Selenite (CaSO4·2H2O) formations commonly associated with the lower levels of the carbonate melt sheets were identified as a likely source for the elevated (SO4)2- concentrations in these sites. Principal Components Analysis separated sites along a conductivity and nutrient gradient on the primary and secondary axes, respectively. This study serves as a baseline for a long-term monitoring program in the Haughton Crater region. (Au)

F, H, B, G, J, E, A
Aluminum; Barium; Bathymetry; Carbon; Carbonates; Chemical properties; Chlorophyll; Climate change; Composition; Copper; Craters; Electrical properties; Environmental impacts; Geology; Ice cover; Iron; Lake ice; Lakes; Logistics; Magnesium; Measurement; Meteorites; Nitrogen; Oligotrophic lakes; Phosphorus; Physical properties; Phytoplankton; Plant nutrition; Silica; Size; Strontium; Sulphates; Surface temperature; Temporal variations; Water pH; Zinc

G0813
Devon Island, Nunavut; Haughton Crater, Nunavut


Are Greater Snow Geese capital breeders? New evidence from a stable-isotope model   /   Gauthier, G.   Bêty, J.   Hobson, K.A.
(Ecology, v. 84, no. 12, Dec. 2003, p.3250-3264, ill.)
(PCSP/PPCP contribution, no. 007-03)
References.
ASTIS record 54897.
Languages: English
Web: doi:10.1890/02-0613
Libraries: ACU

The strategy of relying extensively on stored nutrient reserves for reproduction (capital breeding) was thought to be common in large-bodied birds breeding in harsh environments, such as arctic-nesting geese, but this view has been challenged recently. Our objective was to model inputs to the eggs from stored reserves and from local food plants in Greater Snow Geese (Chen caerulescens atlantica) breeding in the high Arctic, using a new approach based on stable-isotope signatures. Snow Geese and their eggs were collected during laying from 1999 to 2001 (N = 66 females and 110 eggs). We analyzed the isotopic signature (delta 13C and delta 15N) of egg constituents (lipid-free yolk, yolk lipid, and albumen), goose tissues (lipid-free breast muscles, abdominal fat, and whole liver) and of the food plants eaten by laying geese in the Arctic (graminoids and forbs). We applied a two-isotope mixing model approach to delineate nutrient input to eggs quantitatively. Differences in the isotopic signature of endogenous reserves and arctic food plants were relatively large (5.3-8.0‰ for Delta delta 13C and 7.5‰ for Delta delta 15N) because reserves were accumulated in southern staging areas where geese feed in farmlands and estuarine habitats. The percentage of egg nutrients derived from exogenous sources (food consumed in the Arctic) was higher than from endogenous (body) reserves and varied little among the three years. Isotopic signatures indicated that endogenous reserves contributed 33% of lipid-free yolk nutrients, 27% of albumen, and 20% of yolk lipid, on average. Isotopic signatures of egg constituents of individual females were more strongly related to those of liver than endogenous sources (breast muscles or abdominal fat), indicating that the endogenous isotopic signature was diluted by a dietary input in the liver. We also found evidence of seasonal variation in the use of endogenous reserves. Late-laying females apparently invested proportionally more endogenous reserves in their eggs than did early layers, but not those laying larger clutches. We conclude that Greater Snow Geese use a mixed capital/income breeding strategy. Our study shows that isotopic composition of tissues can be used to infer the contribution of exogenous vs. endogenous sources of nutrients for egg formation where inputs differ isotopically. (Au)

I, J, H
Age; Animal food; Animal growth; Animal health; Animal population; Biological sampling; Bird nesting; Carbon; Effects monitoring; Fats; Forecasting; Gender differences; Greater Snow Geese; Internal organs; Isotopes; Mass spectrometry; Mathematical models; Nitrogen; Plants (Biology); Proteins; Seasonal variations; Size; Temporal variations; Tundra ecology

G0813
Bylot Island, Nunavut; Sirmilik National Park, Nunavut


Late Wisconsinan buildup and wastage of the Innuitian Ice Sheet across southern Ellesmere Island, Nunavut   /   England, J.H.   Atkinson, N.   Dyke, A.S.   Evans, D.J.A.   Zreda, M.
(Canadian journal of earth sciences, v. 41, no. 1, Jan. 2004, p. 39-61, ill., maps)
(PCSP/PPCP contribution, no. 010-03)
References.
ASTIS record 57266.
Languages: English
Web: doi:10.1139/e03-082
Libraries: ACU

During the Late Wisconsinan, a precursor of the Prince of Wales Icefield, southern Ellesmere Island, formed a prodigious ice divide of the Innuitian Ice Sheet. Initial buildup occurred after 19 ka BP, when the icefield advanced west (inland) across Makinson Inlet from margins similar to present. Subsequent reversal of flow to the east required ice divide migration to the west onto a plateau that is largely ice-free today. From this divide, a trunk glacier flowed eastward through Makinson Inlet to join the Smith Sound Ice Stream en route to northern Baffin Bay. Westward flow from this divide filled Baumann Fiord, depositing a granite dispersal train that extends a further 600 km across the archipelago to the polar continental shelf. Deglaciation of most of Makinson Inlet occurred catastrophically at ~9.3 ka BP, forming a calving bay that thinned the Innuitian divide, thereby triggering deglaciation of most of Baumann Fiord by 8.5 ka BP. Ninety 14C dates on Holocene shells and driftwood constrain deglacial isochrones and postglacial emergence curves on opposite sides of the former Innuitian divide. Isobases drawn on the 8 ka BP shoreline rise northwest towards Eureka Sound, the axis of maximum former ice thickness. Ice margins on Ellesmere Island were similar to present from ~50-19 ka BP (spanning marine isotope stages 3 and 2). However, significant regional variation in ice extent during this interval is recorded by ice rafting from the Laurentide Ice Sheet into Baffin Bay. Later buildup of the Innuitian Ice Sheet occurred during the low global sea level that defines the last glacial maximum (18 ka BP). We also suggest that the Innuitian Ice Sheet was influenced by the buttressing and subsequent removal of the Greenland Ice Sheet along eastern Ellesmere Island. (Au)

F, A, B, I, D
Ablation; Accumulation; Beaches; Bones; Bowhead whales; Calving (Ice); Deglaciation; Driftwood; Flow; Geological time; Glacial deposits; Glacial epoch; Glacial landforms; Glaciation; Glaciers; Ice divides; Ice sheets; Mollusks; Pleistocene epoch; Radiocarbon dating; Recent epoch; Sea level; Sediments (Geology); Shorelines; Spatial distribution; Thickness

G0813, G0815
Baumann Fiord region, Nunavut; Baumann Fiord, Nunavut; Bjorne Peninsula, Nunavut; Eureka Sound region, Nunavut; Eureka Sound, Nunavut; Makinson Inlet region, Nunavut; Makinson Inlet, Nunavut; Prince of Wales Icefield, Nunavut; Svendsen Peninsula, Nunavut; Vendom Fiord region, Nunavut; Vendom Fiord, Nunavut


Geochemistry of the active layer and near-surface permafrost, Mackenzie Delta region, Northwest Territories, Canada   /   Kokelj, S.V.   Burn, C.R.
(Canadian journal of earth sciences, v. 42, no. 1, Jan. 2005, p. 37-48, ill., map)
(PCSP/PPCP contribution, no. 011-03)
References.
ASTIS record 62617.
Languages: English
Web: doi:10.1139/E04-089
Libraries: ACU

The soluble ion content of the active layer and near-surface permafrost was determined at 41 sites in the Mackenzie delta region, Northwest Territories, Canada. In delta soils, Ca2+ and Mg2+ are the dominant soluble cations, but the quantity and relative abundance of Na+ increase with proximity to the Beaufort Sea coast. Soils beneath frequently flooded surfaces are ion rich in comparison with ground above the level of decadal flooding. Within a terrain type, near-surface permafrost soil solute concentrations are similar between paired cores spaced <1 m apart, but at greater distances (cores spaced 3-13 m apart), solute concentrations are significantly different. Comparatively low soil solute concentrations in old upland surfaces near Inuvik may be a result of progressive removal of soluble materials from the active layer and permafrost during periods of deeper thaw. In sandy silt alluvium, solutes excluded during downward freezing may accumulate at the base of the active layer and be sequestered by a rising permafrost table. At sites with finer grained clayey silts, the correspondence between zones of ice and cation enrichment indicates coupled movement of water and solutes during freeze-back of the active layer and development of aggradational ice. Solute enrichment of near-surface permafrost is greatest at fine-grained ice-rich alluvial sites, where mean concentrations in permafrost are up to 7.5 times greater than those in the active layer. (Au)

C, F, A, H, J, B
Active layer; Alders; Bearberry; Calcium; Cores; Electrical properties; Environmental impacts; Floods; Frozen ground; Geochemistry; Ground ice; Lichens; Magnesium; Measurement; Moisture content of permafrost; Mosses; Permafrost; Physical properties; Plant distribution; Plant growth; Plant succession; Plant-soil relationships; Plant-water relationships; Poplars; River deltas; Runoff; Salinity; Sedimentation; Shrubs; Sodium; Soil chemistry; Soil freezing; Soil moisture; Soil percolation; Soil texture; Soils; Spruces; Taiga ecology; Temporal variations; Thawing; Tundra ponds; Willows

G0812
Inuvik region, N.W.T.; Mackenzie Delta, N.W.T.


Ground ice and soluble cations in near-surface permafrost, Inuvik, Northwest Territories, Canada   /   Kokelj, S.V.   Burn, C.R.
(Permafrost and periglacial processes, v. 14, no. 3, July/Sept. 2003, p. 275-289, ill., maps)
(PCSP/PPCP contribution, no. 012-03)
References.
ASTIS record 55434.
Languages: English
Web: doi:10.1002/ppp.458
Libraries: ACU

The distribution of segregated ice and soluble ions in near-surface permafrost were investigated in hummocky terrain near Inuvik, Northwest Territories. Soil water content profiles from analyses of drill cores indicate that ice-poor permafrost developed beneath a permafrost table aggrading at approximately 4 cm/a, but an ice-rich zone, 10 to 20 cm thick, was observed beneath a permafrost table that had remained stable for about a decade. Ice-rich intervals 10 to 30 cm thick were observed immediately beneath both a thaw unconformity formed in 1981 and an older, deeper unconformity. In profile, the correspondence between zones of cation and ice enrichment suggests soluble materials were incorporated into permafrost during development of near-surface aggradational ice. Moisture enrichment below an experimentally degrading permafrost table was negligible. Similar ice contents beneath the present permafrost table and the deep thaw unconformity, and the preservation of ice-poor intervals immediately above the 1981 and deep thaw unconformities indicate limited vertical ice enrichment. The estimated rates of ice accumulation in two-decade-old permafrost are on the order of mm/a, but ice accumulation above older unconformities indicates that, in aggregate, these initial rates decrease with time. The ground ice and soluble cations sequestered in near-surface permafrost comprise an important pool of water and nutrients that may be released into the active layer during periods of deeper thaw. (Au)

C, N, H, J
Active layer; Biomass; Chemical properties; Cores; Fire ecology; Forest fires; Formation; Ground ice; Hummocks; Mathematical models; Moisture content of permafrost; Moisture transfer; Permafrost; Permeability; Plant-soil relationships; Seasonal variations; Soil percolation; Soil profiles; Soil temperature; Temporal variations; Thawing; Unfrozen water content of permafrost

G0812, G0811
Caribou Hills, N.W.T.; Garry Island, N.W.T.; Herschel Island, Yukon; Inuvik region, N.W.T.; Mackenzie Delta, N.W.T.; Mayo, Yukon; Richards Island, N.W.T.


Comparative physical and chemical limnology of two Canadian High Arctic regions : Alert (Ellesmere Island, NU) and Mould Bay (Prince Patrick Island, NWT)   /   Antoniades, D.   Douglas, M.S.V.   Smol, J.P.
(Archiv für Hydrobiologie, v.158, no. 4, Dec. 2003, p. 485-516, ill., maps)
(PCSP/PPCP contribution, no. 015-03)
Appendices.
References.
ASTIS record 73767.
Languages: English
Web: doi:10.1127/0003-9136/2003/0158-0485
Libraries: ACU

The physical and chemical limnological characteristics of 65 lakes and ponds from two areas in the Canadian High Arctic were examined to determine differences in regional limnology due to geological and vegetational characteristics, as well as other climate factors. Sites in the Alert region of northern Ellesmere Island had relatively low concentrations of total phosphorus (median TP = 9.1 µg/l), and total N (median = 0.465 mg/l). Dissolved organic carbon (DOC) concentrations were relatively low (median = 2.7mg/l) reflecting the sparsity of vegetation in the region. Within the Alert dataset, there were pronounced differences in water chemistry between small tundra ponds and larger, deeper lakes. The first axis of a principal components analysis of the Alert dataset reflected conductivity and nutrient gradients (lambda = 0.28), while the second axis (lambda = 0.20) was related to metal concentrations. Mould Bay sites on Prince Patrick Island had relatively high concentrations of TP (mean = 16.5 µg/l), total N (mean = 0.616mg/l), and DOC (mean = 6.7mg/l). Mean total N and DOC were at the highest levels yet measured from any similar high arctic limnological survey, while mean TP was the second highest high arctic value yet recorded in our surveys. A principal components analysis of the Mould Bay data indicated that the two dominant gradients in the dataset were conductivity and related variables (lambda = 0.30) and nutrients (lambda = 0.19). The differences in water chemistry variables between Mould Bay and all previous high arctic surveys is attributable to the relatively dense vegetation and deep soils present at Mould Bay relative to Alert and other high arctic regions. (Au)

F, B, H, E, J
Bathymetry; Carbon; Carbonates; Chemical properties; Chlorophyll; Climate change; Dissolved organic carbon; Effects monitoring; Effects of climate on plants; Electrical properties; Fresh-water biology; Fresh-water ecology; Geology; Ice cover; Lake-atmosphere interaction; Lakes; Measurement; Metals; Nitrogen; Numeric databases; Oligotrophic lakes; Phosphorus; Physical properties; Plant distribution; Silica; Soils; Temperature; Temporal variations; Topography; Trace elements; Tundra ponds; Water pH; Water quality

G0812, G0813
Alert, Nunavut; Mould Bay (Weather Station), N.W.T.


A sediment accumulation sensor for use in lacustrine and marine sedimentation studies   /   Lamoureux, S.F.
(Geomorphology, v. 68, no. 1-2, 15 May 2005, p. 17-23, ill.)
(PCSP/PPCP contribution, no. 017-03)
References.
ASTIS record 59713.
Languages: English
Web: doi:10.1016/j.geomorph.2004.02.014
Libraries: ACU

A design for a sediment flux sensor is provided for use in sedimentation studies in lacustrine and shallow marine environments. The sensor utilizes an optical system to measure sediment accumulation with a data logger. Unlike other passive or mechanical sediment trapping systems, the sediment flux sensor records the time of deposition precisely and therefore is useful for investigating the linkages between external processes (e.g., hydrological) and sedimentation. (Au)

B, F, G
Accumulation; Design and construction; Effects monitoring; Instruments; Lakes; Measurement; Optical properties; River discharges; River ice; Sedimentation; Suspended solids; Temporal variations

G0813
Lord Lindsay River region, Nunavut; Lord Lindsay River, Nunavut; Sanagak Lake, Nunavut


A 750-yr record of autumn snowfall and temperature variability and winter storminess recorded in the varved sediments of Bear Lake, Devon Island, Arctic Canada   /   Lamoureux, S.F.   Gilbert, R.
(Quaternary research, v. 61, no. 2, Mar. 2004, p. 134-147, ill., maps)
(PCSP/PPCP contribution, no. 018-03)
References.
ASTIS record 57413.
Languages: English
Web: doi:10.1016/j.yqres.2003.11.003
Libraries: ACU

The varve record from High Arctic, proglacial Bear Lake reveals a regionally coherent hydroclimatic signal as well as complexities due to changing hydroclimatic and limnologic conditions. Varve formation is strongly dependent on underflows that exhibit variability in strength during the past 750 yr. Periods with reduced underflow sedimentation and accumulation rates fail to produce varves in the distal part of the lake. Isolated coarse silt and sand grains occur in 80% of the varves and are interpreted to be niveo-aeolian in origin. Coarse (>500 µm) sand grains deposited on the lake ice by strong winter winds are notably less common since A.D. 1850, likely due to reduced storminess. Regression of the varve thickness record with meteorological records indicates high correlations with autumn (September and October) temperatures and total monthly snowfall. These correlations are best at times when underflow activity is sufficiently strong to produce varves throughout the lake. The close association with warmer temperatures and snow-bearing synoptic systems moving north in Baffin Bay suggests that the primary climate signal in the varves is varying autumn snow pack that controls nival discharge in the following year. The similarity between the other records of melt season temperature and sea-ice cover and the Bear Lake record suggests that summer and autumn conditions were generally similar across the Baffin Bay region through much of the last millennium. (Au)

E, B, V, F, G
Bottom sediments; Climate change; Climatology; Cores; Ice caps; Ice cover; Isotopes; Lake ice; Lakes; Measurement; Melting; Sand; Sea ice; Seasonal variations; Sedimentation; Snow; Storms; Suspended solids; Temporal variations

G0813, G09
Baffin Bay-Davis Strait; Bear Lake, Nunavut; Devon Island, Nunavut


Break-up of the largest Arctic ice shelf and associated loss of an epishelf lake   /   Mueller, D.R.   Vincent, W.F.   Jeffries, M.O.
(Geophysical research letters, v. 30, no. 20, Oct. 2003, 4 p., ill., maps)
(PCSP/PPCP contribution, no. 019-03)
References.
ASTIS record 71791.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/175.pdf
Web: doi:10.1029/2003GL017931
Libraries: ACU

Field observations and RADARSAT imagery of the Ward Hunt Ice Shelf (lat. 83°N, long. 74°W), Nunavut, Canada, show that it broke in two over the period 2000 to 2002, with additional fissuring and further ice island calving. The fracturing caused the drainage of an ice-dammed epishelf lake (Disraeli Fiord), a rare ecosystem type. Reductions in the freshwater volume of Disraeli Fiord occurred from 1967 to the present and accompanied a significant rise in mean annual air temperature over the same period in this far northern region. The recent collapse of ice shelves in West Antarctica has been interpreted as evidence of accelerated climate change in that region. Similarly, the inferred thinning and observed fragmentation of the ice shelf, plus the drainage of the epishelf lake, are additional evidence for climate change in the High Arctic. (Au)

E, F, G, J, D
Atmospheric temperature; Breakup; Calving (Ice); Climate change; Drainage; Effects of climate on ice; Fracturing; Fresh-water ecology; Glacial melt waters; Heat budgets; Hydrography; Hydrology; Ice shelves; Lakes; Marine ecology; Microbial ecology; Ocean temperature; Salinity; SAR; Sea water; Seasonal variations; Snowmelt; Temporal variations; Water masses

G0813, G0815, G15, G03
Antarctic Peninsula; Arctic Ocean; Disraeli Fiord, Nunavut; Ward Hunt Ice Shelf, Nunavut


Rapid disappearance of perennial ice on Canada's most northern lake   /   Paquette, M.   Fortier, D.   Mueller, D.R.   Sarrazin, D.   Vincent, W.F.
(Geophysical research letters, v. 42, no. 5, 16 Mar. 2015, p.1433-1440, ill.)
(PCSP/PPCP contribution, no. 019-03)
References.
ASTIS record 80809.
Languages: English
Web: doi:10.1002/2014GL062960
Libraries: ACU

Field records, aerial photographs, and satellite imagery show that the perennial ice cover on Ward Hunt Lake at Canada's northern coast experienced rapid contraction and thinning after at least 50 years of relative stability. On all dates of sampling from 1953 to 2007, 3.5 to 4.3 m of perennial ice covered 65-85% of the lake surface in summer. The ice cover thinned from 2008 onward, and the lake became ice free in 2011, an event followed by 26 days of open water conditions in 2012. This rapid ice loss corresponded to a significant increase in melting degree days (MDD), from a mean (±SD) of 80.4 (±36.5) MDD (1996-2007) to 136.2 (±16.4) MDD (2008-2012). The shallow bathymetry combined with heat advection by warm inflows caused feedback effects that accelerated the ice decay. These observations show how changes across a critical threshold can result in the rapid disappearance of thick perennial ice. (Au)

E, F, G, J
Aerial photography; Atmospheric temperature; Bathymetry; Breakup; Climate change; Effects of climate on ice; Fresh-water ecology; Glacial melt waters; Ground penetrating radar; Heat budgets; Hydrology; Ice scouring; Ice shelves; Lake ice; Lakes; Melting; Microbial ecology; SAR; Seasonal variations; Snow; Solar radiation; Temperature; Temporal variations; Thickness

G0813
Small Lake, Nunavut; Ward Hunt Ice Shelf, Nunavut


Gradient analysis of cryoconite ecosystems from two polar glaciers   /   Mueller, D.R.   Pollard, W.H.
(Polar biology, v. 27, no. 2, Jan. 2004, p. 66-74, ill., maps)
(PCSP/PPCP contribution, no. 021-03)
References.
ASTIS record 46247.
Languages: English
Web: doi:10.1007/s00300-003-0580-2
Libraries: ACU

The cylindrical meltholes present in the ablation zones of many glaciers (termed cryoconite holes) contain complex microbial communities. A canonical correspondence analysis (CCA) of community structure and environmental gradients for cryoconite holes on two glaciers was undertaken. The Canada Glacier (77°37'S, 162°55'E) is located in the McMurdo Dry Valleys of Antarctica. The White Glacier (79°27'N, 90°40'W) is located on Axel Heiberg Island, Nunavut Territory, Canada. These glaciers are at similar, yet antipodal latitudes, are roughly the same size and endure approximately the same mean annual temperature. The Canada Glacier cryoconite communities were found to be significantly (P=0.001) associated with six environmental variables, which together explained 55% of the biological variation. The White Glacier cryoconite communities were not significantly associated with environmental variables. The differences in CCA results were attributed to the relative amount of disturbance and isolation between each glaciers cryoconite holes. Canada Glacier cryoconite holes were mostly ice-covered and undisturbed by meltwater flow, whereas high meltwater production and open cryoconite holes on the White Glacier may continually reset the community structure and habitat variability due to inter-hole mixing. (Au)

J, F, H
Ablation; Algae; Aspect; Bacteria; Biological sampling; Biomass; Cryoconite; Cyanophyceae; Electrical properties; Glacial melt waters; Glaciers; Growing season; Melting; Microbial ecology; Plant distribution; Plant nutrition; Plant taxonomy; Seasonal variations; Slopes; Solar radiation

G0813, G15
Canada Glacier, Antarctic regions; White Glacier, Nunavut


Catastrophic die-off of Peary caribou on the western Queen Elizabeth Islands, Canadian High Arctic   /   Miller, F.L.   Gunn, A.
(Arctic, v. 56, no. 4, Dec. 2003, p. 381-390, ill., maps)
(PCSP/PPCP contribution, no. 022-03)
References.
ASTIS record 52874.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic56-4-381.pdf
Web: doi:10.14430/arctic635
Libraries: ACU

The Peary caribou (Rangifer tarandus pearyi) is an endangered species in Canada, having been in an overall decline since 1961. Sightings of Peary caribou were compared from two aerial searches, in 1993 and 1998, on Bathurst and its neighbouring islands, western Queen Elizabeth Islands in the Canadian High Arctic. The comparison indicated a near-total (98%) cataclysmic decline in the number of Peary caribou seen per unit of search effort. In summer 1993, 2400 caribou were counted during 33.8 h of low-level helicopter searches. In contrast, in summer 1998, only 43 caribou were seen within the same area during 35.2 h of low-level helicopter searches. The frequency of observation was markedly different: 118.3 caribou/100 min in 1993, but only 2.0 caribou/100 min in 1998. The number of carcasses indicated that the decline resulted from deaths and not from mass emigration. Males died at a disproportionately higher rate than females among all 1+ yr old caribou, and bulls (4+ yr) compared to cows (3+ yr) had died at an even greater rate. Widespread, prolonged, exceptionally severe snow and ice conditions from 1994-95 to 1996-97 caused the die-off. Trends in snowfall are consistent with predictions for global warming in the western Canadian High Arctic. Future climate change may increase the frequency of years with unfavorable snow and ice conditions, which could prevent or at least impede future recovery of Peary caribou populations on the western Queen Elizabeth Islands, particularly to sizes that would support subsistence harvesting. (Au)

I, E, F, H, G, L
Aerial surveys; Age; Animal food; Animal mortality; Animal population; Animal reproduction; Atmospheric temperature; Bioclimatology; Caribou; Climate change; Effects of climate on ice; Effects of climate on plants; Effects of climate on snow; Endangered species; Extirpation; Gender differences; Grazing; Helicopters; Icing; Icing conditions; Necropsy; Plant growth; Plants (Biology); Seasonal variations; Snow; Starvation; Temporal variations; Winds

G0812, G0813
Bathurst Island, Nunavut; Cameron Island, Nunavut; Marc, Ile, Nunavut; Massey Island, Nunavut; Queen Elizabeth Islands, N.W.T./Nunavut; Vanier, Ile, Nunavut


Chinese swamp cypress (Glyptostrobus) in the fossil forests of Axel Heiberg Island, Nunavut, Canada   /   Postnikoff, A.C.L.   Basinger, J.F.
(Breaking the ice : proceedings of the 7th ACUNS (Inter)National Student Conference on Northern Studies = Briser la glace : démarches de la 7ième Conférence (inter)nationale de l'AUCEN des étudiants en études nordiques. Occasional publications series - Canadian Circumpolar Institute, no. 55, 2004, p. 131-139, ill., 2 maps)
(PCSP/PPCP contribution, no. 023-03)
References.
ASTIS record 56413.
Languages: English
Libraries: ACU

The fossil forests of Axel Heiberg Island provide an exceptional record of plant life in the Far North during the Eocene (45 million years ago), a time of global warmth. Preservation at this locality is exceptional, with mummified stumps and leaf litter found in situ, the fossils almost unaltered by time. The preserved flora is dominated by a small number of deciduous coniferous and broad-leaved plants, including Glyptostrobus, the Chinese Swamp Cypress, a member of the cedar and redwood family and a close relative of the American Swamp Cypress (Taxodium) and Redwood. The single extant species of Glyptostrobus, confined to a small area of Southern China, is nearly indistinguishable from the Axel Heiberg material, and is similar to remains found in rocks as old as 70 million years throughout the circumpolar North. Global climatic change that ultimately led to Quaternary glaciation drastically restricted its distribution in Asia, and eliminated the genus entirely from North America and Europe. The Axel Heiberg fossils provide insight into the evolution and phytogeography of this once-abundant conifer, and provide vivid evidence for warm, moist climate in the ancient Arctic, where mean summer temperatures exceeded 20°C, and winter temperatures rarely, if ever, fell below freezing. Appreciation of paleoclimate is essential to an understanding of processes influencing global climate and climate change. (Au)

B, H, E
Cedars; Climate change; Conifers; Eocene epoch; Evolution (Biology); Extirpation; Fossil forests; Glaciation; Leaves; Palaeobotany; Palaeoclimatology; Palynology; Plant anatomy; Plant distribution; Plant taxonomy; Seeds; Tertiary period; Wetlands

G0813
Asia; Axel Heiberg Island, Nunavut; China; Geodetic Hills, Nunavut; Thailand; Vietnam


Stratigraphy and glaciotectonic structures of permafrost deformed beneath the northwest margin of the Laurentide Ice Sheet, Tuktoyaktuk coastlands, Canada   /   Murton, J.B.   Waller, R.I.   Hart, J.K.   Whiteman, C.A.   Pollard, W.H.   Clark, I.D.
(Journal of glaciology, v. 50, no.170, June 2004, p. 399-412, ill., maps)
(PCSP/PPCP contribution, no. 024-03)
References.
ASTIS record 58815.
Languages: English
Web: doi:10.3189/172756504781829927
Libraries: ACU

The upper 5-20 m of ice-rich permafrost at three sites overridden by the northwest margin of the Laurentide ice sheet in the Tuktoyaktuk Coastlands, western Arctic Canada, comprise massive ice beneath ice-rich diamicton or sandy silt. The diamicton and silt contain (1) truncated ice blocks up to 15 m long, (2) sand lenses and layers, (3) ice veins dipping at 20-30°, (4) ice lenses adjacent and parallel to sedimentary contacts, and (5) ice wedges. The massive ice is interpreted as intrasedimental or buried basal glacier ice, and the diamicton and silt as glacitectonite that has never thawed. Deformation of frozen ground was mainly ductile in character. Deformation was accompanied by sub-marginal erosion of permafrost, which formed an angular unconformity along the top of the massive ice and supplied ice clasts and sand bodies to the overlying glacitectonite. After deformation and erosion ceased, postglacial segregated ice and ice-wedge ice developed within the deformed permafrost. (Au)

A, B, C, F
Crystals; Deformation; Erosion; Frozen ground; Glacial epoch; Glacial geology; Glacial landforms; Glacier ice; Ground ice; Ice sheets; Ice wedges; Isotopes; Mathematical models; Permafrost; Petrography; Pleistocene epoch; Sediments (Geology); Stratigraphy; Structural geology

G0812, G07, G0811
Canadian Beaufort Sea; Eskimo Lakes region, N.W.T.; Herschel Island, Yukon; Inuvialuit Settlement Region mainland, N.W.T.; Liverpool Bay region, N.W.T.; Liverpool Bay, N.W.T.; Mackenzie Delta, N.W.T.; Nicholson Island, N.W.T.; North Head (69 43 N, 134 26 W), N.W.T.; Pullen Island, N.W.T.; Richards Island, N.W.T.; Summer Island, N.W.T.; Tuktoyaktuk Peninsula, N.W.T.; Yukon North Slope


Ecosystems on ice : the microbial ecology of Markham Ice Shelf in the High Arctic   /   Vincent, W.F.   Mueller, D.R.   Bonilla, S.
(Cryobiology, v. 48, no. 2, Apr. 2004, p. 103-112, ill., maps)
(PCSP/PPCP contribution, no. 026-03)
References.
ASTIS record 55847.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/180.pdf
Web: doi:10.1016/j.cryobiol.2004.01.006
Libraries: ACU

Microbial communities occur throughout the cryosphere in a diverse range of ice-dominated habitats including snow, sea ice, glaciers, permafrost, and ice clouds. In each of these environments, organisms must be capable of surviving freeze-thaw cycles, persistent low temperatures for growth, extremes of solar radiation, and prolonged dormancy. These constraints may have been especially important during global cooling events in the past, including the Precambrian glaciations. One analogue of these early Earth conditions is the thick, landfast sea ice that occurs today at certain locations in the Arctic and Antarctic. These ice shelves contain liquid water for a brief period each summer, and support luxuriant microbial mat communities. Our recent studies of these mats on the Markham Ice Shelf (Canadian high Arctic) by high performance liquid chromatography (HPLC) showed that they contain high concentrations of chlorophylls a and b, and several carotenoids notably lutein, echinenone and ß-carotene. The largest peaks in the HPLC chromatograms were two UV-screening compounds known to be produced by cyanobacteria, scytonemin, and its decomposition product scytonemin-red. Microscopic analyses of the mats showed that they were dominated by the chlorophyte genera cf. Chlorosarcinopsis, Pleurastrum, Palmellopsis, and Bracteococcus, and cyanobacteria of the genera Nostoc, Phormidium, Leptolyngbya, and Gloeocapsa. From point transects and localized sampling we estimated a total standing stock on this ice shelf of up to 11,200 tonnes of organic matter. These observations underscore the ability of microbial communities to flourish despite the severe constraints imposed by the cryo-ecosystem environment. (Au)

J, F, G, E, H, I, A
Algae; Bacteria; Biomass; Carotenoids; Chemical properties; Chlorophyll; Chromatography; Climate change; Cyanophyceae; Diatoms; Fluorometry; Glacial melt waters; Glacier lakes; Ice shelves; Microbial ecology; Microorganisms; Physical properties; Phytoplankton; Plant growth; Plant nutrition; Primary production (Biology); Puddles; Sediments (Geology); Soil microorganisms; Surface properties; Topography; Water pH

G0813, G03, G15
Markham Fiord, Nunavut; McMurdo Ice Shelf, Antarctic regions; Quttinirpaaq National Park, Nunavut; Ward Hunt Ice Shelf, Nunavut


Local ecological knowledge of Ivory Gull declines in Arctic Canada   /   Mallory, M.L.   Gilchrist, H.G.   Fontaine, A.J.   Akearok, J.A.
(Arctic, v. 56, no. 3, Sept. 2003, p. 293-298)
(PCSP/PPCP contribution, no. 027-03)
References.
ASTIS record 52331.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic56-3-293.pdf
Web: doi:10.14430/arctic625
Libraries: ACU

We gathered local ecological knowledge (LEK) on the ivory gull (Pagophila eburnea) from residents of three High Arctic communities in eastern Canada. This gull has always been uncommon, but Inuit had suggested that numbers of gulls were declining. LEK from Grise Fiord and Resolute Bay was clear and consistent, indicating that far fewer gulls are currently observed near the community compared to 25 years ago. The LEK from Arctic Bay was less consistent, although in general, community members thought that the species was less commonly observed. Observations from nonsystematic surveys by local wildlife officers corroborated the LEK data, and an aerial survey of the known colony locations on the Brodeur Peninsula (near Arctic Bay) found only one gull. Collectively, this information suggests that ivory gull populations are declining across the species' Canadian range. Systematic surveys will be needed to confirm these perceived declines. (Au)

I, T, V
Animal distribution; Animal migration; Animal population; Bird nesting; Food; Inuit; Ivory Gulls; Social surveys; Traditional knowledge

G0813
Arctic Bay (Hamlet), Nunavut; Brodeur Peninsula, Nunavut; Grise Fiord (Settlement), Nunavut; Resolute, Nunavut


Dioxins, furans, and non-ortho PCBs in Canadian Arctic seabirds   /   Braune, B.M.   Simon, M.
(Environmental science & technology, v. 37, no. 14, July 15, 2003, p.3071-3077, ill., maps)
(PCSP/PPCP contribution, no. 028-03)
References.
ASTIS record 53565.
Languages: English
Web: doi:10.1021/es021082p
Libraries: ACU

This is the first account of PCDDs [polychorinated dibenzo-p-dioxins], PCDFs [polychorinated dibenzo-furans], and non-ortho PCBs [polychlorinated biphenyls] in Canadian Arctic seabirds. Livers and eggs of thick-billed murres, northern fulmars, and black-legged kittiwakes were collected in 1975 and 1993 from Prince Leopold Island in Lancaster Sound, Canada. Detectable concentrations of PCDDs, PCDFs, and non-ortho PCBs were found in all the Arctic seabird samples analyzed. Of the PCDD congeners assayed, only 2,3,7,8-substituted PCDDs were detected in the samples, whereas non-2,3,7,8-substituted PCDFs were found in addition to 2,3,7,8-substituted PCDFs in some of the samples. The predominant PCDD/F congener found in the livers of all three species was 2,3,4,7,8-PnCDF, both in 1975 and 1993. Concentrations of most dioxins and furans decreased in the fulmars and kittiwakes between 1975 and 1993 but increased in the murres. Of the non-ortho PCBs measured, PCB-126 occurred in the highest concentrations and contributed the majority of the non-ortho PCB-TEQ in all three species in both years. The highest concentrations of dioxins and furans as well as the highest TEQ [toxic equivalents] values were found in the northern fulmar livers in both 1975 and 1993. Concentrations of some of the PCDDs and PCDFs are among the highest reported for Canadian Arctic biota. (Au)

J, I
Animal mortality; Animal physiology; Bioaccumulation; Biological sampling; Biomagnification; Bird nesting; Chromatography; Dioxins; Effects monitoring; Environmental impacts; Fulmars; Furans; Heavy metals; Internal organs; Kittiwakes; Mass spectrometry; Measurement; Metabolism; PCBs; Pollution; Temporal variations; Thick-billed Murres; Toxicity

G0813
Prince Leopold Island Migratory Bird Sanctuary, Nunavut


Trophic interactions in a High Arctic Snow Goose colony   /   Gauthier, G.   Bêty, J.   Giroux, J.-F.   Rochefort, L.
(Biology of the Canadian Arctic : a crucible for change in the 21st century. Integrative and comparative biology, v. 44, no. 2, Apr. 2004, p. 119-129, ill.)
(PCSP/PPCP contribution, no. 001-04)
References.
Papers from the symposium "Biology of the Canadian Arctic: a crucible for change in the 21st century" presented at the Annual Meeting of the Society for Integrative and Comparative Biology, 4-8 January 2003 in Toronto.
ASTIS record 59756.
Languages: English
Web: doi:10.1093/icb/44.2.119
Libraries: ACU

We examined the role of trophic interactions in structuring a high arctic tundra community characterized by a large breeding colony of greater snow geese (Chen caerulescens atlantica). According to the exploitation ecosystem hypothesis of Oksanen et al. (1981), food chains are controlled by top-down interactions. However, because the arctic primary productivity is low, herbivore populations are too small to support functional predator populations and these communities should thus be dominated by the plant/herbivore trophic-level interaction. Since 1990, we have been monitoring annual abundance and productivity of geese, the impact of goose grazing, predator abundance (mostly arctic foxes, Alopex lagopus) and the abundance of lemmings, the other significant herbivore in this community, on Bylot Island, Nunavut, Canada. Goose grazing consistently removed a significant proportion of the standing crop (40%) in tundra wetlands every year. Grazing changed plant community composition and reduced the production of grasses and sedges to a low-level equilibrium compared to the situation where the presence of geese had been removed. Lemming cyclic fluctuations were strong and affected fox reproduction. Fox predation on goose eggs was severe and generated marked annual variation in goose productivity. Predation intensity on geese was closely related to the lemming cycle, a consequence of an indirect interaction between lemming and geese via shared predators. We conclude that, contrary to the exploitation ecosystem hypothesis, both the plant/herbivore and predator/prey interactions are significant in this arctic community. (Au)

I, H, J
Animal ecology; Animal food; Animal mortality; Animal population; Animal reproduction; Arctic foxes; Biological productivity; Biological sampling; Biomass; Bird nesting; Food chain; Grasses; Grazing; Greater Snow Geese; Lemmings; Measurement; Mosses; Plant distribution; Predation; Primary production (Biology); Sedges; Snowy Owls; Temporal variations; Trophic levels; Tundra ecology; Wetlands; Wildlife habitat

G0813
Bylot Island, Nunavut


Freshwater diatom biogeography in the Canadian Arctic Archipelago   /   Bouchard, G.   Gajewski, K.   Hamilton, P.B.
(Journal of biogeography, v. 31, no. 12, Dec. 2004, p.1955-1973, ill., maps)
(PCSP/PPCP contribution, no. 002-04)
Appendix.
References.
ASTIS record 55715.
Languages: English
Web: doi:10.1111/j.1365-2699.2004.01143.x
Libraries: ACU

Aim: Document the biogeographical distributions of diatoms in the Canadian Arctic in relation to environmental factors. Location: The Canadian Arctic Archipelago. Methods: Diatoms were extracted from lake sediments and treated using standard methods. Rarefaction-estimated species richness, diatom concentrations (valves/cc), and diatom abundance were mapped using a Geographic Information System. The physical and chemical parameters of the lakes were measured. Results: A total of 326 taxa from 63 genera were found in 62 lakes of the study area. Up to 85 and as low as eight taxa were identified in any one lake, and rarefaction-estimated species richness correlated with lake size. Nearby lakes could have greatly different diatom assemblages. Many taxa showed limited distributions. Response surfaces and ordination techniques indicate that a large number of taxa prefer colder regions of the Arctic while the abundance of others was influenced by lake water chemical parameters such as TKN and SiO2. Main conclusions: Although many taxa were common and found across the study area, diatom assemblages showed regional differences in the Arctic. Some taxa were not found in either the northern or southern parts of the Archipelago and others were restricted to particular regions. Newly delineated genera showed interpretable geographical patterns and could be related to environmental factors, suggesting that this more natural grouping may enhance our understanding of diatom ecology. Geographical, physical, and chemical factors are needed to explain diatom distributions in the Arctic. (Au)

H, F, J, E, B
Atmospheric temperature; Benthos; Bottom sediments; Carbon; Chlorophyll; Cores; Diatoms; Electrical properties; Fresh-water biology; Geographic information systems; Geology; Growing season; Identification; Lakes; Logistics; Measurement; Metals; Microscopes; Nitrogen; Phosphorus; Plant distribution; Plant ecology; Plant growth; Plant nutrition; Plant taxonomy; Plants (Biology); Primary production (Biology); Rocks; Seasonal variations; Silica; Size; Temperature; Trace elements; Water pH

G0813, G0812
Axel Heiberg Island, Nunavut; Bathurst Island, Nunavut; Boothia Peninsula, Nunavut; Cornwallis Island, Nunavut; Devon Island, Nunavut; Ellesmere Island, Nunavut; Prince of Wales Island, Nunavut; Somerset Island, Nunavut; Victoria Island, N.W.T./Nunavut


Late Holocene syngenetic ice-wedge polygons development, Bylot Island, Canadian Arctic Archipelago   /   Fortier, D.   Allard, M.
(Canadian journal of earth sciences, v. 41, no. 8, Aug. 2004, p. 997-1012, ill., maps)
(PCSP/PPCP contribution, no. 003-04)
References.
ASTIS record 57285.
Languages: English
Web: doi:10.1139/e04-031
Libraries: ACU

The initial configuration of the syngenetic ice-wedge polygons that developed in the outwash plain of glacier C-79 after 6000 BP was modified by the accumulation of wind-blown and organic sediments that began after 3670 ±110 BP. The late Holocene sedimentation led to an increase in the thermal contraction coefficient of the soil and the formation of third- and fourth-order contraction cracks, partially explaining the current configuration of the polygonal network. The upturning of the sedimentary strata bordering the ice wedges was associated with the summer thermal expansion and resulting internal creep of the soil. The mean annual soil displacement coefficient was in the order of 2.5-2.7 × 10**-5/°C at the thousand-year scale. The late Holocene sedimentary strata under the centre of the polygons were undisturbed, which will make it possible to use this sedimentary record in further studies to attempt paleoenvironmental reconstructions from cores. (Au)

C, A, B, H, E
Carbon; Cores; Creep; Deformation; Effects of climate on permafrost; Equipment and supplies; Formation; Fracturing; Ground ice; Ground penetrating radar; Growth; Ice wedges; Loess; Logistics; Measurement; Microscopes; Minerals; Movement; Palaeoclimatology; Patterned ground; Peat; Permafrost; Radiocarbon dating; Recent epoch; Sedimentation; Sediments (Geology); Size; Soil mechanics; Soil moisture; Soil pH; Soil profiles; Soil temperature; Strain; Stress; Thermal regimes; Topography

G0813
Bylot Island, Nunavut; Navy Board Inlet region, Nunavut


Frost-cracking conditions, Bylot Island, eastern Canadian Arctic Archipelago   /   Fortier, D.   Allard, M.
(Permafrost and periglacial processes, v. 16, no. 2, Apr./June 2005, p. 145-161, ill., maps)
(PCSP/PPCP contribution, no. 004-04)
References.
ASTIS record 61069.
Languages: English
Web: doi:10.1002/ppp.504
Libraries: ACU

The meteorological and ground temperature conditions under which frost cracking takes place in an ice-wedge polygon site were inferred from electric cables that were probably severed by ground thermal contraction. Between 1997 and 2002, the severing of cables in the active layer occurred mostly in January. The daily mean air temperature when the cables broke ranged from -25 to -40°C, with a mean of -34.3°C. They generally broke after a drop in air temperature of about 7.9°C over a mean period of 18 h, at a mean atmospheric cooling rate of -0.5°C/h. The breaks occurred a few hours to a few days after the arrival of persistently cold temperatures, the daily mean ground temperature being -22.9°C at 2 cm under the surface (1997-2002) and -18.6°C at the permafrost table (2000-2002). The mean thermal gradient in the active layer at the time of breakage was -10.9°C/m. Maximum ground cooling rates during breaking episodes were located in the active layer or at the top of permafrost. (Au)

C, E, F, J, I
Active layer; Atmospheric temperature; Cold weather performance; Deformation; Effects monitoring; Effects of climate on permafrost; Environmental impacts; Equipment and supplies; Frost action; Frozen ground; Grazing; Greater Snow Geese; Heat transmission; Instruments; Mechanical properties; Meteorology; Patterned ground; Seasonal variations; Snow cover; Soil temperature; Solar radiation; Spatial distribution; Temporal variations; Thawing; Thermal properties; Thermal regimes

G0813
Bylot Island, Nunavut; Pond Inlet (Hamlet), Nunavut


Effects of neck bands on reproduction and survival of female Greater Snow Geese   /   Reed, E.T.   Gauthier, G.   Pradel, R.
(The Journal of wildlife management, v. 69, no. 1, Jan. 2005, p. 91-100, ill.)
(PCSP/PPCP contribution, no. 008-04)
References.
ASTIS record 60299.
Languages: English
Web: doi:10.2193/0022-541X(2005)069<0091:EONBOR>2.0.CO;2
Libraries: ACU

An assumption of mark-recapture studies is that the marker has no effect on the animal. Neck bands have been used extensively for goose research, but there has long been concern that they may have negative effects on some demographic parameters, and recent studies have yielded contradictory results. We evaluated the effects of neck bands on adult female greater snow geese (Chen caerulescens atlantica) by contrasting breeding propensity and apparent survival of geese marked with both a plastic neck band and a metal leg band and those marked solely with metal leg bands over an 11-year period on Bylot Island, Nunavut Territory, Canada. The use of multistate mark-recapture models also allowed us to estimate neck band loss and to obtain survival and capture probabilities that were not biased by such loss. Finally, we tested the effects of neck bands on other reproductive parameters (laying date, clutch size and nest success) over a 3-year period. Neck-banded females had decreased clutch size and capture probabilities, but their apparent survival rate, nest initiation and hatching dates, and nest survival were not affected compared to leg-banded only or unbanded females. Breeding propensity, indexed by capture probabilities of neck-banded females was, on average, 48% lower that that of leg-banded-only females but clutch size was only 10% lower. Neck band loss of females was low in this population (3% per year). We urge researchers to be cautious in the use of neck bands for estimation of population parameters and that the potential negative effects of neck bands be assessed as it is likely to be species-specific. (Au)

I, N
Animal behaviour; Animal health; Animal live-capture; Animal migration; Animal mortality; Animal population; Animal reproduction; Animal tagging; Bird nesting; Effects monitoring; Environmental impacts; Greater Snow Geese; Mathematical models; Radio tracking of animals; Research; Testing; Wildlife management

G0813
Bylot Island, Nunavut; Sirmilik National Park, Nunavut


Basal ice facies and supraglacial melt-out till of the Laurentide Ice Sheet, Tuktoyaktuk coastlands, western Arctic Canada   /   Murton, J.B.   Whiteman, C.A.   Waller, R.I.   Pollard, W.H.   Clark, I.D.   Dallimore, S.R.
(Quaternary science reviews, v. 24, no. 5-6, Mar., 2005, p. 681-708, ill., maps)
(PCSP/PPCP contribution, no. 009-04)
References.
ASTIS record 58391.
Languages: English
Web: doi:10.1016/j.quascirev.2004.06.008
Libraries: ACU

Glacially-deformed massive ice and icy sediments (MI-IS) in the Eskimo Lakes Fingerlands and Summer Island area of the Tuktoyaktuk Coastlands, western Arctic Canada, show, in the same stratigraphic sequences, features characteristic of both basal glacier ice and intrasedimental ice. Basal-ice features comprise (1) ice facies and facies groupings similar to those from the basal ice layers of contemporary glaciers and ice sheets in Alaska, Greenland and Iceland; (2) ice crystal fabrics similar to those from basal ice in Antarctica and ice-cored moraines on Axel Heiberg Island, Canada; and (3) a thaw or erosional unconformity along the top of the MI-IS, buried by glacigenic or aeolian sediments. Intrasedimental ice consists of pore ice and segregated ice formed within Pleistocene sands deposited before glacial overriding. The co-existence of basal and intrasedimental ice within the MI-IS records their occurrence within the basal ice layer of the Laurentide Ice Sheet. Stagnation of the ice sheet and melt-out of till from the ice surface allowed burial and preservation of the basal ice layer on a regional scale. The widespread occurrence of supraglacial melt-out till with clast fabrics similar to those in the underlying ice suggests that such till can be well preserved during partial thaw of a continental ice sheet in lowlands underlain by continuous permafrost. (Au)

C, A, B, F
Clay; Coasts; Crystals; Deformation; Deglaciation; Deuterium; Flow; Formation; Fracturing; Glacial deposits; Glacial epoch; Glacial melt waters; Glaciation; Glacier ice; Gravel; Ground ice; Ice wedges; Isotopes; Laurentide Ice Sheet; Mass wasting; Melting; Minerals; Oxygen; Periglacial landforms; Permafrost; Petrography; Physical properties; Pleistocene epoch; Quaternary period; Recent epoch; Sand; Sedimentation; Sediments (Geology); Silt; Soil texture; Spatial distribution; Stratigraphy; Thawing; Thermokarst

G0812, G0813
Barnes Ice Cap, Nunavut; Bylot Island, Nunavut; Eskimo Lakes region, N.W.T.; Kittigazuit Bay region, N.W.T.; Liverpool Bay region, N.W.T.; Mackenzie Delta, N.W.T.; Mason Bay region, N.W.T.; North Head (69 43 N, 134 26 W), N.W.T.; Peninsula Point, N.W.T.; Richards Island, N.W.T.; Summer Island, N.W.T.; Toker Point, N.W.T.; Tuktoyaktuk Peninsula, N.W.T.


Geology and Neoarchean tectonic setting of the Central Hearne supracrustal belt, Western Churchill Province, Nunavut, Canada   /   Hanmer, S.   Sandeman, H.A.   Davis, W.J.   Aspler, L.B.   Rainbird, R.H.   Ryan, J.J.   Relf, C.   Peterson, T.D.
(Precambrian research, v.134, no. 1-2, 20 Sept. 2004, p. 63-83, ill., maps)
(PCSP/PPCP contribution, no. 012-04)
References.
ASTIS record 55664.
Languages: English
Web: doi:10.1016/j.precamres.2004.04.005
Libraries: ACU

The Central Hearne supracrustal belt, one of the largest Neoarchean "greenstone" terranes in the Canadian Shield, occurs in the Hearne domain of the Western Churchill Province, one of the largest, poorly known fragments of Archean crust on Earth. The belt contains two isotopically juvenile volcano-plutonic assemblages (I: ~2710-2690 Ma, and II: ~2685-2680 Ma), separated in time by localised, ~2690 Ma, greenschist-facies deformation (D1), and overlain by ~2680 Ma Archean siliciclastic and chemical sedimentary rocks. Extensive, penetrative, greenschist-facies regional deformation (D2) occurred at ~2680 Ma, with amphibolite-facies metamorphism localised in the aureoles of isotopically juvenile synkinematic plutons. In many respects, the Central Hearne supracrustal belt is similar to other Neoarchean "greenstone" belts that have been interpreted in terms of arc-subduction systems, e.g. the Abitibi greenstone belt of the Superior Province. However, the principal tectonic characteristics of the Central Hearne supracrustal belt include: (i) location in an anomalously wide (>225 km) swath of penecontemporaneous juvenile crust that extends across much of the Hearne domain; (ii) close, primary intercalation of contemporaneous volcanic rocks of MORB-like and arc-like geochemical signatures, coupled with highly discontinuous volcanic map units; (iii) abundant intermediate to felsic volcanic rocks that do not represent a localised, laterally extensive volcanic arc edifice; and (iv) the development of isolated, independent, felsic volcanic centres throughout the magmatic history of the belt. These features are incompatible with oceanic arc or plateau models. We propose that the early history (assemblage I) of the Central Hearne supracrustal belt may be analogous with a modified extensional, suprasubduction "infant arc" model, such as that described for the earliest (Eocene) phase of construction of the Izu-Marianas-Bonin and Tonga arc-trench systems of the Southwest Pacific Ocean. The later history (assemblage II) may reflect attempted initiation of classical subduction and arc construction. (Au)

B
Archaean era; Deformation; Geochemistry; Geological time; Intrusions (Geology); Lava; Magmatism; Metamorphism (Geology); Sedimentary rocks; Structural geology; Volcanism

G0813
Heninga Lake region, Nunavut; Kaminak Lake region, Nunavut; Quartzite Lake region, Nunavut; Tootyak Lake region, Nunavut


Whole-rock and Nd isotopic geochemistry of Neoarchaean granitoids and their bearing on the evolution of the Central Hearne supracrustal belt, Western Churchill Province, Canada   /   Sandeman, H.A.   Hanmer, S.   Davis, W.J.   Ryan, J.J.   Peterson, T.D.
(Precambrian research, v.134, no. 1-2, 20 Sept. 2004, p. 143-167, ill., maps)
(PCSP/PPCP contribution, no. 013-04)
Appendix.
References.
ASTIS record 55666.
Languages: English
Web: doi:10.1016/j.precamres.2004.05.005
Libraries: ACU

The Central Hearne supracrustal belt (CHSB), Hearne domain, Western Churchill Province forms a large (ca. 30,000 km²), greenschist grade Neoarchaean (2711-2660 Ma) terrane of predominant metavolcanic and less common metasedimentary rocks intruded by three groups of plutonic rocks. Pre-tectonic group 1 plutons (>2690 Ma) include rare gabbro, dominant diorite to tonalite and rare granodiorite and granite. These intrude and incorporate angular inclusions of cogenetic volcanic rocks and have variably developed foliations. Syn-tectonic group 2 plutons (2690-2679 Ma) comprise rare gabbro and diorite, predominant tonalite and granodiorite and rare granite, and exhibit N-S-trending, ductiley deformed supracrustal schlieren-rich intrusive margins. Post-tectonic group 3 plutons are rare, and comprise either potassic, biotite monzogranite or alkalic nepheline syenite and rare carbonatite. Abundant tonalite to granodiorite, biotite ± hornblende - bearing mineralogies and metaluminous and generally low-medium K2O compositions, indicate that most rocks are I- or M-type granitoids. Molecular Na-Ca-K variations and AFM indices indicate transitional calc-alkaline - trondjhemitic trends with both tholeitic and calc-alkaline affinities. Rare earth and incompatible element variations suggest that most granitoids exhibit volcanic arc- or tonalite-trondhjemite-granodiorite (TTG)-like abundances with multi-element patterns varying gradationally from La-poor (LaN/YbN < 12) to La-rich compositions (LaN/YbN > 12). Nd isotopic values overlap with contemporaneous depleted mantle indicating that the granitoids represent melts derived from predominantly juvenile mantle or crust. La-poor rocks likely formed through low-P anatexis of amphibolitic crust with plagioclase + amphibole ± clinopyroxene present, whereas high-La rocks were generated via high-P partial melting of a garnet + clinopyroxene-bearing protolith (plausibly a subducted slab). Granitoid evolution from early dominant low-P, tholeiitic and calc-alkaline melts, to later, predominant high-P, high-Al2O3 TTG melts, reflects a change in the tectonomagmatic setting at ca. 2690 Ma. Construction of proto-arc crust from ca. 2711-2690 Ma, and extension of the leading edge of normal (ca. 40 km) Archaean oceanic crust, in response to lithospheric processes analogous to those of the Eocene SW Pacific Ocean, resulted in asthenospheric upwelling, intrusion of mantle-derived melts into the lower crust, and their subsequent ascent and fractionation. Partial melting at the base of the extended, thick oceanic crust likely yielded sparse high-La melts at this time. At ca. 2690 Ma, a change from an extensional to a shortening regime resulted in initiation of subduction of adjacent oceanic lithosphere, partial melting of the eclogitic downgoing slab and generation of voluminous, high-P, La-rich granitoid magmas. This yielded less abundant low-P, La-poor melts emplaced into the "infant-arc" crust during and following tectonism. The complete sequence was intruded by late potassic granites derived from tonalitic lower crust and alkalic magmas that originated in the lithospheric mantle. (Au)

B
Geochemistry; Granite; Intrusions (Geology); Isotopes; Magmatism; Metamorphism (Geology); Petrography; Sedimentary rocks; Trace elements; Volcanism

G0813
Carr Lake region, Nunavut; Heninga Lake region, Nunavut; Kaminak Lake region, Nunavut; Quartzite Lake region, Nunavut; Snug Lake region, Nunavut; Turquetil Lake region, Nunavut


Neoarchaean volcanic rocks, Central Hearne supracrustal belt, Western Churchill Province, Canada : geochemical and isotopic evidence supporting intra-oceanic, supra-subduction zone extension   /   Sandeman, H.A.   Hanmer, S.   Davis, W.J.   Ryan, J.J.   Peterson, T.D.
(Precambrian research, v.134, no. 1-2, 20 Sept. 2004, p. 113-141, ill., maps)
(PCSP/PPCP contribution, no. 014-04)
Appendix.
References.
ASTIS record 55665.
Languages: English
Web: doi:10.1016/j.precamres.2004.03.014
Libraries: ACU

The Kaminak segment of the Central Hearne supracrustal belt (CHSB) Western Churchill Province, Canada, comprises a diverse sequence of Neoarchaean volcanic and less abundant metasedimentary rocks that were emplaced as two assemblages between 2695-2711 Ma and 2681-2686 Ma, respectively. These are intruded by uncommon pre-tectonic diorites and tonalites (ca. 2691 Ma), voluminous syn-tectonic tonalites and granodiorites (ca. 2679-2686 Ma) and, rare post-tectonic potassic monzogranite and syenite (ca. 2659-2666 Ma). Metasedimentary rocks include turbidites, epiclastic tuffs, minor iron formation (oxide) and rare volcanic conglomerates. Volcanic rocks of assemblage I include abundant pillowed and massive basalts to andesites with less common silicic lavas, tuffs and volcaniclastic debris flow deposits. Assemblage II contains voluminous silicic tuff and volcaniclastic debris flow deposits but fewer basaltic to andesitic flows. The critical diagnostic feature of the CHSB is the stratigraphic intercalation of compositionally diverse basaltic, andesitic and felsic volcanic rocks throughout both assemblages. Mapping, U-Pb geochronology and lithogeochemistry suggest that an initial MORB-like basaltic plain containing widespread intercalations of dacite to rhyolite was replaced at ca. 2688 Ma by a relatively short-lived, dacite to rhyolite dominated magmatic environment characterized by localized felsic volcanic centres and a bloom of 2686-2679 Ma tonalitic to granodioritic plutons. Basaltic to andesitic rocks are dominated by iron-rich tholeiites, although the proportion of calc-alkaline rocks increases with silica content. Felsic volcanic rocks all exhibit calc-alkaline affinities. The wide range in chemistry of the basaltic to andesitic rocks of both volcanic assemblages implies diverse mantle sources capable of generating voluminous MORB-, with less common ARC-, NEB(OIB)- and rare BABB-like rocks. Similarly, the variable composition of the felsic volcanic rocks indicates both anatexis of eclogitic to garnetiferous mafic crust and also extensive fractionation of mafic precursors in crustal magma chambers. Two geochemically distinct, arc-like mafic suites were generated through contamination of primary mantle-derived magmas by juvenile, ca. 2700 Ma silicic crust either in their mantle source or through assimilation upon ascent. epsilon Nd(t) isotopic data are comparable to contemporaneous depleted mantle with only local evidence for incorporation of older, >>>2700 Ma crust. The CHSB may have formed via tectono-magmatic processes comparable to those of the Eocene, infant-arcs of the SW Pacific, whereby the formation of a thick sequence of coeval, intercalated, compositionally diverse mantle- and crustal-derived rocks, are generated in an extensional supra-subduction setting. The cessation of supra-subduction zone extension at ca. 2688 Ma, was followed by the short-lived development of felsic volcanic edifices (incipient arc), the extrusion of mafic to felsic magmas and the concomitant intrusion of voluminous syn-kinematic tonalitic plutons. This accompanied a major change in the tectono-magmatic setting accompanying and presumably following the termination of extensional, supra-subduction zone processes. (Au)

B
Andesite; Archaean era; Basalt; Diorite; Eocene epoch; Geochemistry; Igneous rocks; Intrusions (Geology); Isotopes; Mapping; Mass spectrometry; Petrology; Pyroclastics; Stratigraphy; Trace elements; Volcanism

G0813
Carr Lake region, Nunavut; Heninga Lake region, Nunavut; Kaminak Lake region, Nunavut; Quartzite Lake region, Nunavut; Turquetil Lake region, Nunavut


Temporal evolution of the Neoarchean Central Hearne supracrustal belt : rapid generation of juvenile crust in a suprasubduction zone setting   /   Davis, W.J.   Hanmer, S.   Sandeman, H.A.
(Precambrian research, v.134, no. 1-2, 20 Sept. 2004, p. 85-112, ill., maps)
(PCSP/PPCP contribution, no. 015-04)
References.
ASTIS record 55663.
Languages: English
Web: doi:10.1016/j.precamres.2004.02.002
Libraries: ACU

New U-Pb zircon ages are reported for 17 volcanic, plutonic and sedimentary rocks from the Neoarchean Central Hearne supracrustal belt in the Western Churchill Province of the Canadian Shield. The Central Hearne supracrustal belt, historically referred to as the Rankin-Ennadai greenstone belt, is a major granite-greenstone terrain with a strike length of over 700 km. This study, focused on the central and eastern segments of the belt in the Kaminak Lake area, represents the first detailed chronological study of this extensive greenstone belt. The geochronological data indicate rapid formation of crust between 2711 and 2667 Ma. Rocks of the oldest assemblage (I) formed between 2711 and 2691 Ma and consist of mixed tholeiitic and calc-alkaline mafic and felsic, submarine to subaerial volcanic rocks. Minor plutonic rocks (Group 1) are associated with this interval. A younger assemblage (II) of volcanic rock with significant calc-alkaline plutonic rocks (Group 2) developed between 2686 and 2679 Ma. A period of deformation (D1) locally separates the two assemblages. Major regional, penetrative deformation and metamorphism developed during the latter stages of the plutonic event at ca. 2680 Ma. An extensive belt of metasedimentary rocks and associated iron formation was deposited after 2681 Ma, based on ages of detrital zircon. The youngest events include intrusion of 2666.4 ± 1.1 Ma post-deformational granite (Group 3), 2659 Ma carbonatite [Can. J. Earth Sci. 29 (1992) 896], and deposition of post-2660 Ma conglomerates and arenites of possible "Timiskiming"-type. There is no indication of contributions from Mesoarchean crust either in inherited grains in igneous rocks, or as detrital grains in sedimentary rocks. Although the evolutionary sequence has parallels to greenstone belts such as the Abitibi belt, in terms of the rock types and relative timing of events, there are some differences. We envision development of the belt in an extensional, oceanic suprasubduction environment. (Au)

B, H, J
Deformation; Geological time; Granite; Igneous rocks; Intrusions (Geology); Metamorphism (Geology); Palaeoecology; Pyroclastics; Radioactive dating; Sedimentary rocks; Sedimentation; Structural geology; Volcanism

G0813
Ellesmere Island, Nunavut; Kaminak Lake region, Nunavut


Some sources and sinks of monomethyl and inorganic mercury on Ellesmere Island in the Canadian High Arctic   /   St. Louis, V.L.   Sharp, M.J.   Steffen, A.   May, A.   Barker, J.   Kirk, J.L.   Kelly, D.J.A.   Arnott, S.E.   Keatley, B.   Smol, J.P.
(Environmental science & technology, v. 39, no. 8, Apr. 15, 2005, p.2686-2701, ill., 1 map)
(PCSP/PPCP contribution, no. 016-04)
References.
ASTIS record 57708.
Languages: English
Web: doi:10.1021/es049326o
Libraries: ACU

We identified some of the sources and sinks of monomethyl mercury (MMHg) and inorganic mercury (HgII) on Ellesmere Island in the Canadian High Arctic. Atmospheric Hg depletion events resulted in the deposition of Hg(II) into the upper layers of snowpacks, where concentrations of total Hg (all forms of Hg) reached over 20 ng/L. However, our data suggest that much of this deposited Hg(II) was rapidly photoreduced to Hg(0) which then evaded back to the atmosphere. As a result, we estimate that net wet and dry deposition of Hg(II) during winter was lower at our sites (0.4-5.9 mg/ha) than wet deposition in more southerly locations in Canada and the United States. We also found quite high concentrations of monomethyl Hg (MMHg) in snowpacks (up to 0.28 ng/L), and at times, most of the Hg in snowpacks was present as MMHg. On the Prince of Wales Icefield near the North Water Polynya, we observed a significant correlation between concentrations of Cl and MMHg in snow deposited in the spring, suggesting a marine source of MMHg. We hypothesize that dimethyl Hg fluxes from the ocean to the atmosphere through polynyas and open leads in ice, and is rapidly photolyzed to MMHg-Cl. We also found that concentrations of MMHg in initial snowmelt on John Evans Glacier (up to 0.24 ng/L) were higher than concentrations of MMHg in the snowpack (up to 0.11 ng/L), likely due to either sublimation of snow or preferential leaching of MMHg from snow during the initial melt phase. This springtime pulse of MMHg to the High Arctic, in conjunction with climate warming and the thinning and melting of sea ice, may be partially responsible for the increase in concentrations of Hg observed in certain Arctic marine mammals in recent decades. Concentrations of MMHg in warm and shallow freshwater ponds on Ellesmere Island were also quite high (up to 3.0 ng/L), leading us to conclude that there are very active regions of microbial Hg(II) methylation in freshwater systems during the short summer season in the High Arctic. (Au)

J, F, E, G, H, I
Air pollution; Atmospheric chemistry; Atmospheric circulation; Carbon; Chemistry; Chlorine; Chromatography; Environmental impacts; Evaporation; Fluorometry; Gases; Glacial melt waters; Glaciers; Lakes; Logistics; Measurement; Mercury; Microorganisms; Ocean-atmosphere interaction; Ozone; Pollution; Polynyas; Rain; Runoff; Sea ice; Seasonal variations; Snow; Snow stratigraphy; Snow surveys; Snow water equivalent; Snowmelt; Sodium; Solar radiation; Spatial distribution; Spectroscopy; Sublimation; Sulphates; Temporal variations; Thickness; Water pH

G0813, G0815, G09
Alert Inlet, Nunavut; Alert, Nunavut; Ellesmere Island, Nunavut; John Evans Glacier, Nunavut; North Water Polynya, Baffin Bay; Prince of Wales Icefield, Nunavut; Quttinirpaaq National Park, Nunavut


A long-term field study (1951-2003) of ventifacts formed by katabatic winds at Paulatuk, western Arctic coast, Canada   /   Mackay, J.R.   Burn, C.R.
(Canadian journal of earth sciences, v. 42, no. 9, Sept. 2005, p.1615-1635, ill., maps)
(PCSP/PPCP contribution, no. 017-04)
References.
ASTIS record 62496.
Languages: English
Web: doi:10.1139/E05-061
Libraries: ACU

Field measurements have been made since 1951 on hundreds of ventifacts abraded by strong, southerly, katabatic winds that blow in winter and summer past Paulatuk, a small western Arctic coastal settlement. Sand is commonly entrained by the strongest winds in winter. The ventifacts, all glacial erratics deposited prior to 12 ka BP, have been gradually rotated by the southerly winds until the long axes of most ventifacts now trend approximately east–west, normal to the katabatic winds. In contrast, pebbles have a slightly preferred north–south orientation, parallel to the katabatic winds. The facets on sandstone and diabase ventifacts are almost planar, but are rounded on granites and hackled on limestones, reflecting the influence of both solution and abrasion. Abrasion is evident on the built structures in Paulatuk, but despite the over 50 years of observation, abrasion of the ventifacts has been virtually undetectable. The extremely slow abrasion rate has been estimated from: observations on two ventifacts from 1951 to 2003; photographic comparisons and observations of 60 ventifacts from 1968 to 2003; optical examination of 14 granite slabs, polished and unpolished, exposed to abrasion from 1967 to 1976; and comparisons of the windward and leeward sides of six large rock caches built with ventifacts probably long before 1900. If the present rates of abrasion are representative of Holocene conditions, ventifact formation has probably taken much of postglacial time. The increase in vegetation cover around many rocks between 1968 and 2003 suggests that the climate has changed in the last three decades. (Au)

E, B, F, H, V, A, M, L
Airports; Aspect; Blowing snow; Buildings; Climate change; Coasts; Creep; Design and construction; Effects of climate on plants; Frost heaving; Glacial deposits; Granite; Gravel; Graves; History; Lichens; Limestone; Measurement; Photography; Plant cover; Plant distribution; Recent epoch; Rocks; Sand; Seasonal variations; Sedimentation; Sediments (Geology); Size; Spatial distribution; Temporal variations; Velocity; Weathering; Wind erosion; Winds

G0812, G07
Darnley Bay region, N.W.T.; Darnley Bay, N.W.T.; Melville Hills, N.W.T./Nunavut; Paulatuk region, N.W.T.; Paulatuk, N.W.T.


Heightened sensitivity of a poorly buffered High Arctic lake to Late-Holocene climatic change   /   Michelutti, N.   Douglas, M.S.V.   Wolfe, A.P.   Smol, J.P.
(Quaternary research, v. 65, no. 3, May 2006, p. 421-430, ill., maps)
(PCSP/PPCP contribution, no. 019-04)
References.
ASTIS record 59668.
Languages: English
Web: doi:10.1016/j.yqres.2006.02.001
Libraries: ACU

A diatom-based paleolimnological investigation was conducted on late Holocene sediments from a poorly buffered lake, informally named "Rock Basin Lake", on Ellesmere Island, Arctic Canada. The fossil diatom record is unlike any other obtained thus far from high arctic regions, exhibiting dynamic assemblage shifts over the entire 3300 yr sedimentary record. Multiple proxies (i.e., diatoms, pH reconstructions, biogenic silica, C/N ratios, total organic carbon) appear to sensitively track rapid limnological changes, which are associated with distinct climate intervals as inferred from other regional proxy records. The highly responsive nature of the diatom assemblages in Rock Basin Lake, relative to those recorded from nearby alkaline sites, appears to be related to this lake's limited ability to buffer changes in pH. The dynamic species responses suggest that the diatoms in Rock Basin Lake are faithfully tracking climatic changes, and that low-alkalinity lakes may provide the most sensitive diatom-based paleolimnological records from high arctic regions. (Au)

B, F, H, E, J
Bottom sediments; Climate change; Cores; Diatoms; Environmental impacts; Fresh-water biology; Fresh-water ecology; Lakes; Palaeobotany; Palaeoclimatology; Palaeoecology; Recent epoch; Water pH

G0813
Ellesmere Island, Nunavut; Rock Basin Lake, Nunavut


Ground-ice stratigraphy and formation at North Head, Tuktoyaktuk coastlands, western Arctic Canada : a product of glacier - permafrost interactions   /   Murton, J.B.
(Permafrost and periglacial processes, v. 16, no. 1, Jan./Mar. 2005, p. 31-50, ill., maps)
(PCSP/PPCP contribution, no. 022-04)
References.
ASTIS record 58389.
Languages: English
Web: doi:10.1002/ppp.513
Libraries: ACU

Glacially deformed permafrost at North Head, in the Tuktoyaktuk Coastlands of western Arctic Canada, contains a complex ground-ice stratigraphy that formed during the course of the last glacial-interglacial cycle. Two generations of ground ice are distinguished within a single stratigraphic sequence. Pre-deformation ice has been glacially deformed or eroded beneath the cold-based margin of the Laurentide Ice Sheet (LIS) during Marine Isotope Stage 2. Such ice comprises (1) buried basal ice, (2) massive segregated ice and (3) ice clasts subglacially eroded from pre-existing ground ice. In contrast, post-deformation ice has not been glacially disturbed because it formed during or after deglaciation; it includes (4) dykes and sills of intrusive ice, (5) massive segregated-intrusive ice, (6) ice wedges and composite wedges, (7) segregated ice and (8) pool ice. The superimposition of post-deformation intrusive ice and massive segregated-intrusive ice into permafrost containing pre-deformation ground ice indicates that substantial quantities of overpressurized water were injected into ice-marginal permafrost during or after deglaciation. The required external water source for the post-deformation intrusive ice was probably overpressurized subpermafrost groundwater in front of the retreating margin of the LIS. Injection of this water into proglacial permafrost hydraulically fractured the permafrost and formed ice dykes, ice sills and massive segregated-intrusive ice. A two-stage model of massive-ice development can be reconciled with known permafrost and glacial conditions in the ice-marginal context of the Late Wisconsinan LIS. The model probably applies to some other glaciated terrains of the western Canadian Arctic. (Au)

C, A, B, F
Clay; Coasts; Deformation; Deglaciation; Formation; Fracturing; Glacial deposits; Glacial epoch; Glacier ice; Ground ice; Groundwater; Ice wedges; Laurentide Ice Sheet; Mass wasting; Permafrost; Quaternary period; Recent epoch; Sand; Sediments (Geology); Silt; Spatial distribution; Stratigraphy

G0812
North Head (69 43 N, 134 26 W), N.W.T.; Pullen Island, N.W.T.; Richards Island, N.W.T.; Toker Point, N.W.T.; Tuktoyaktuk Peninsula, N.W.T.


Benthic diatom autecology and inference model development from the Canadian High Arctic Archipelago   /   Antoniades, D.   Douglas, M.S.V.
(Journal of phycology, v. 41, no. 1, Feb. 2005, p. 30-45, ill., maps)
(PCSP/PPCP contribution, no. 023-04)
References.
ASTIS record 61116.
Languages: English
Web: doi:10.1111/j.1529-8817.2005.04049.x
Libraries: ACU

Diatom assemblages were analyzed from 64 lakes and ponds from Alert, Ellesmere Island and Mould Bay, Prince Patrick Island in the Canadian High Arctic Archipelago. Diverse water chemistry conditions and diatom communities were present in these sites. Small benthic taxa typically dominated diatom communities; however, assemblages were markedly different between Alert and Mould Bay sites in response to disparate water chemistry characteristics in the two regions. The most abundant taxa belonged to the genera Navicula, Cymbella, Achnanthes, Nitzschia, and Pinnularia. Canonical correspondence analysis indicated that pH, specific conductivity, dissolved organic carbon, and total phosphorus were the most important limnological variables in determining species composition. Diatom inference models were developed for pH, specific conductivity, and dissolved organic carbon using weighted averaging and weighted averaging partial least squares techniques; these had root mean square error of prediction/r2 boot values of 0.40/0.77, 0.28/0.70, and 0.24/0.55, respectively. These models are applicable to sites with large ranges of taxonomic and limnological variation and will allow the reconstruction of past changes of climate-related limnological parameters from biostratigraphic records in future paleolimnological studies. (Au)

H, F, E, J, B
Bottom sediments; Carbon cycling; Chemical properties; Climate change; Diatoms; Dissolved organic carbon; Electrical properties; Eutrophic lakes; Fresh-water biology; Fresh-water ecology; Growing season; Lakes; Mathematical models; Microbial ecology; Mosses; Oligotrophic lakes; Palaeoclimatology; Palaeoecology; Palaeontology; Phosphorus; Plant distribution; Plant taxonomy; Solar radiation; Stratigraphy; Tundra ponds; Water pH

G0813, G0812
Alert region, Nunavut; Mould Bay region, N.W.T.


Decline and recovery of a High Arctic wolf-prey system   /   Mech, L.D.
(Arctic, v. 58, no. 3, Sept. 2005, p. 305-307)
(PCSP/PPCP contribution, no. 030-04)
References.
ASTIS record 57379.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic58-3-305.pdf
Web: doi:10.14430/arctic432
Libraries: ACU

A long-existing system of wolves (Canis lupus), muskoxen (Ovibos moschatus), and arctic hares (Lepus arcticus) in a 2600 km² area of Canada's High Arctic (80° N latitude) began collapsing in 1997 because of unusual adverse summer weather but recovered to a level at which all three species were reproducing by 2004. Recovery of wolf presence and reproduction appeared to be more dependent on muskox increase than on hare increase. (Au)

I, J, E
Animal distribution; Animal food; Animal mortality; Animal population; Animal reproduction; Arctic foxes; Climate change; Denning; Hares; Meteorology; Muskoxen; Predation; Temporal variations; Tundra ecology

G0813
Eureka region, Nunavut; Fosheim Peninsula, Nunavut


Extremotrophs, extremophiles and broadband pigmentation strategies in a High Arctic ice shelf ecosystem   /   Mueller, D.R.   Vincent, W.F.   Bonilla, S.   Laurion, I.
(FEMS microbiology, ecology, v. 53, no. 1, 1 June 2005, p. 73-87, ill., maps)
(PCSP/PPCP contribution, no. 033-04)
References.
ASTIS record 59712.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/185.pdf
Web: doi:10.1016/j.femsec.2004.11.001
Libraries: ACU

Remnant ice shelves along the northern coast of Ellesmere Island, Nunavut, Canada (83°N) provide a habitat for cryo-tolerant microbial mat communities. Bioassays of bacterial and primary production were undertaken to quantify the short-term physiological response of the mats to changes in key variables that characterize this cryo-ecosystem (salinity, irradiance and temperature). The heterotrophic versus autotrophic community responses to these stressors differed markedly. The heterotrophic bacteria were extremophilic and specifically adapted to ambient conditions on the ice shelf, whereas the autotrophic community had broader tolerance ranges and optima outside the ambient range. This latter, extremotrophic response may be partly due to a diverse suite of pigments including oligosaccharide mycosporine-like amino acids, scytonemins, carotenoids, phycobiliproteins and chlorophylls that absorb from the near UV-B to red wavelengths. These pigments provide a comprehensive broadband strategy for coping with the multiple stressors of high irradiance, variable salinity and low temperatures in this extreme cryo-environment. (Au)

H, I, F, J, D
Adaptation (Biology); Amino acids; Bacteria; Bioassays; Biochemistry; Biomass; Chlorophyll; Cold adaptation; Cyanophyceae; Effects of temperature on plants; Heterotrophic bacteria; Ice shelves; Light; Microbial ecology; Photosynthesis; Plant growth; Plant-water relationships; Primary production (Biology); Salinity; Sea water; Solar radiation; Viruses

G0813, G03
Arctic Ocean; Markham Fiord, Nunavut; Ward Hunt Ice Shelf, Nunavut


Morphology and geotechnique of active-layer detachment failures in discontinuous and continuous permafrost, northern Canada   /   Lewkowicz, A.G.   Harris, C.
(Geomorphology, v. 69, no. 1-4, July 2005, p. 275-297, ill., maps)
(PCSP/PPCP contribution, no. 034-04)
References.
ASTIS record 59714.
Languages: English
Web: doi:10.1016/j.geomorph.2005.01.011
Libraries: ACU

Fifty active-layer detachment failures triggered after forest fire in the discontinuous permafrost zone (central Mackenzie Valley, 65° N.) are compared to several hundred others caused by summer meteorological triggers in continuous permafrost (Fosheim Peninsula, Ellesmere Island, 80°N). Most failures fall into compact or elongated morphological categories. The compact type occur next to stream channels and have little internal disturbance of the displaced block, whereas the elongated types can develop on any part of the slope and exhibit greater internal deformation. Frequency distributions of length-to-width and length-to-depth ratios are similar at all sites. Positive pore pressures, expected theoretically, were measured in the field at the base of the thawing layer. Effective stress analysis could predict the instability of slopes in both areas, providing cohesion across the thaw plane was set to zero and/or residual strength parameters were employed. The location of the shear planes or zones in relation to the permafrost table and the degree of post-failure secondary movements (including headwall recession and thermokarst development within the failure track) differed between the localities, reflecting dissimilarity in the environmental triggers and in the degree of ground thermal disturbance. (Au)

A, C, H, N, F, E, B
Active layer; Clay; Deformation; Drainage; Environmental impacts; Forest fires; Geomorphology; Ground ice; Ice wedges; Instruments; Landslides; Mathematical models; Measurement; Meteorology; Neutral stress; Permafrost; Physical properties; Plant-soil relationships; Recent epoch; River banks; Rivers; Sediments (Geology); Slopes; Soil mechanics; Soil moisture; Soil profiles; Soil temperature; Soil texture; Soils; Thaw flow slides; Thawing; Thermokarst; Trees

G0812, G0813
Big Slide Creek region, Nunavut; Black Top Creek region, Nunavut; Fosheim Peninsula, Nunavut; Hot Weather Creek region, Nunavut; Mackenzie River region, N.W.T.; Mackenzie River, N.W.T.; Norman Wells, N.W.T.; Tulita, N.W.T.; Wrigley, N.W.T.


Frequency and magnitude of active-layer detachment failures in discontinuous and continuous permafrost, northern Canada   /   Lewkowicz, A.G.   Harris, C.
(Permafrost and periglacial processes, v. 16, no. 1, Jan./Mar. 2005, p. 115-130, ill., maps)
(PCSP/PPCP contribution, no. 035-04)
References.
ASTIS record 61068.
Languages: English
Web: doi:10.1002/ppp.522
Libraries: ACU

Active-layer detachment failures triggered weeks to months after forest fire in the central Mackenzie Valley (65°N, discontinuous permafrost zone) are compared to others generated almost immediately by summer meteorological conditions on the Fosheim Peninsula, Ellesmere Island (80°N, continuous permafrost zone). Preferred long-axis orientations in both zones vary in relation to valley geometry and ground ice distribution: differential insulation plays no direct role in detachment failure distribution. Rates of geomorphic work over periods of one to two centuries are of the same order of magnitude. Threshold meteorological conditions for initiating failures on the Fosheim Peninsula can be incorporated into a surface heating index, but pre-conditioning of the active layer remains important because rapid thaw does not always initiate activity. Slope pre-conditioning does not occur at the fire-affected sites because the failure zone is within formerly perennially frozen ground. Long-term rates of unit vertical transport at the most active site on the Fosheim Peninsula are similar to those due to debris flow and slushflow in a nearby mountain range. The frequency of potential triggering events at the Ellesmere Island sites is expected to increase if summer climate warms, providing low percentage cloud cover is maintained during periods of high air temperatures. (Au)

C, E, A, J
Active layer; Aerial photography; Aspect; Atmospheric temperature; Climate change; Clouds; Effects of climate on permafrost; Environmental impacts; Forest fires; Frozen ground; Geomorphology; Ground ice; Heat transmission; Meteorology; Moisture transfer; Permafrost; Rain; Seasonal variations; Slopes; Soil temperature; Solar radiation; Spatial distribution; Thaw flow slides; Thawing

G0812, G0813
Big Slide Creek region, Nunavut; Black Top Creek region, Nunavut; Ellesmere Island, Nunavut; Fosheim Peninsula, Nunavut; Hot Weather Creek region, Nunavut; Mackenzie River region, N.W.T.; Sawtooth Range, Nunavut


Icing processes associated with High Arctic perennial springs, Axel Heiberg Island, Nunavut, Canada   /   Pollard, W.H.
(Permafrost and periglacial processes, v. 16, no. 1, Jan./Mar. 2005, p. 51-68, ill., maps)
(PCSP/PPCP contribution, no. 038-04)
References.
ASTIS record 61067.
Languages: English
Web: doi:10.1002/ppp.515
Libraries: ACU

Saline perennial springs have been documented at six locations on Axel Heiberg Island in the Canadian high Arctic. Spring discharge rates, temperatures and chemistry, and associated icing and frost mound formation have been documented at two locations in the Expedition Fiord area since 1988 and at one location near Whitsunday Bay since 1996. Cold Ca- and Na-rich waters discharge near the base of Gypsum Hill and Colour Peak at Expedition Fiord. A large oval-shaped icing up to 2 m thick forms at the base of Gypsum Hill while at Colour Peak the springs have formed a series of gullies and travertine deposits which develop three small icing and frost mounds systems in winter. At Whitsunday Bay cold discharge is from a single outlet and is confined by a deep channel where it forms a salt tufa. Where the channel emerges onto the floodplain a large fan-shaped icing is formed. This paper also documents spring discharge and icing activity from three other non-glacial sources and one glacial source. The icings and frost mounds formed by these springs are very different from those formed by late summer and early winter subglacial discharge. The high solute concentrations lead to freezing-point depression, complex patterns of freezing and the formation of brine icings, together with a variety of mineral precipitates. Freezing-point depression experiments help explain icing hydrology and the spatial pattern of icing formation. (Au)

C, E, F, J, B, A
Aerial surveys; Chemical properties; Climate change; Evaporites; Formation; Frost mounds; Geothermal investigations; Glacial deposits; Glacial melt waters; Groundwater; Hydrology; Icings; Mapping; Mathematical models; Periglacial landforms; Permafrost; Polar deserts; River discharges; Salinity; Seasonal variations; Sedimentation; Snow cover; Spatial distribution; Springs (Hydrology); Temporal variations; Thermal regimes; Travertine

G0813
Axel Heiberg Island, Nunavut; Bunde Fiord region, Nunavut; Colour Peak, Nunavut; Ellesmere Island, Nunavut; Expedition Fiord region, Nunavut; Gypsum Hill, Nunavut; Middle Fiord region, Nunavut; Whitsunday Bay region, Nunavut


Annual development cycle of an icing deposit and associated perennial spring activity on Axel Heiberg Island, Canadian High Arctic   /   Heldmann, J.L.   Pollard, W.H.   McKay, C.P.   Andersen, D.T.   Toon, O.B.
(Arctic, antarctic, and alpine research, v. 37, no. 1, Feb. 2005, p. 127-135, ill., maps)
(PCSP/PPCP contribution, no. 040-04)
References.
ASTIS record 60293.
Languages: English
Web: doi:10.1657/1523-0430(2005)037[0127:ADCOAI]2.0.CO;2
Libraries: ACU

This paper examines the behavior of perennial saline springs and their icings at Expedition Fiord in the Canadian High Arctic during the winter months when temperatures are below the eutectic point of the solution and during the early spring when temperatures are still below freezing but above the eutectic point. The spring outflow begins to freeze when it cools from the discharge temperature which is between -3.5°C and +6°C. As ice forms it remains mixed with the brine forming a salty, icy, slush which lines the sides of the flow channel. Networks of pipes and tunnels also allow the brine to flow under and through the icing before being frozen at the icing perimeter. In late winter complete freezing occurs several hundred meters from the springs' outlets. There appears to be incomplete fractionation of salt during the freezing process and the bulk ice contains 30 to 285 ppt salt. The icing reaches its maximum extent in late winter just before temperatures rise above the eutectic point. In April 2002 the icing had dimensions of 300 m by 700 m, an average thickness of 0.5 m and a total mass of approximately 2 ×10**8 kg. This icing mass is consistent with the flow from the springs during the previous 6 mo. (Au)

C, F, G, B, E
Atmospheric temperature; Crystals; Diapirs; Effects of climate on ice; Folds (Geology); Formation; Frost mounds; Glacial melt waters; Glacier lakes; Groundwater; Ice cover; Ice sheets; Icings; Mass balance; Melting; River ice; Salinity; Salt; Size; Snow; Springs (Hydrology); Stream flow; Temperature; Thickness

G0813
Axel Heiberg Island, Nunavut; Expedition Fiord region, Nunavut; Thompson Glacier, Nunavut; White Glacier, Nunavut


Submerged aquatic bryophytes in Colour Lake, a naturally acidic polar lake with occasional year-round ice-cover   /   Hawes, I.   Andersen, D.T.   Pollard, W.H.
(Arctic, v. 55, no. 4, Dec. 2002, p. 380-388, ill., 2 maps)
(PCSP/PPCP contribution, no. 043-04)
References.
ASTIS record 50676.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic55-4-380.pdf
Web: doi:10.14430/arctic722
Libraries: ACU

Colour Lake is a small, naturally acidic (pH 3.7) lake on Axel Heiberg Island (Canadian High Arctic) that experiences occasional year-round ice cover. We investigated the benthic vegetation of this lake, with a specific aim of determining whether the annual growth of benthic bryophytes reflects the state of summer ice cover. We found the bed of the lake to be almost completely covered by mosses or liverworts to a depth of 22 m. The mosses showed annual growth bands 10-30 mm in length, visible as changes in leaf density and size. Four to five bands retained recognizable leaves and measurable amounts of chlorophyll-a (chla), and up to 12 bands were recognizable from leaf scars. We could not find a consistent relationship between band length and persistence of ice cover for a given year. We suggest that this lack is due to the complex effects of ice cover on moss growth conditions, specifically on the water temperature and irradiance at depth. Photosynthetic characteristics of Calliergon over a range of light and temperature conditions, determined using pulse amplitude-modulated fluorometry, are presented in support of this argument. We conclude that moss banding patterns are an unreliable method of hindcasting episodic failure of ice to melt in Arctic lakes. (Au)

H, F, G, J
Benthos; Bryophytes; Diving; Fluorometry; Fresh-water ecology; Ice cover; Lake ice; Lakes; Liverworts; Mosses; Photosynthesis; Plant distribution; Plant growth; Primary production (Biology); Suspended solids; Temperature

G0813
Colour Lake, Nunavut


Ice content and sensitivity analysis based on landscape interpretation for several sites along the Beaufort Sea coast   /   Pollard, W.   Omelon, C.   Couture, N.   Solomon, S.   Budkewitsch, P.
(Arctic Coastal Dynamics : report of an international workshop, Potsdam (Germany), 26-30 November 2001 / Edited by V. Rachold, J. Brown and S. Solomon. Berichte zur Polar- und Meeresforschung = Reports on polar and marine research, Nr.413, 2002, p. 48-51, ill., maps)
(PCSP/PPCP contribution, no. 046-04)
Extended abstract.
ASTIS record 73750.
Languages: English
Web: http://epic-reports.awi.de/431/1/BerPolarforsch2002413.pdf
Web: doi:10013/epic.10418
Libraries: ACU

Climate change is one of the most important environmental issues facing the North today and its consequences will affect all northern ecosystems and human activities. Not only will the effects of climate change be observed sooner in the Arctic than in temperate regions, but also the magnitude of this change will be greater. Furthermore, nowhere else are landscapes, ecosystems and human activities more vulnerable to its effects, especially in coastal areas underlain by ground ice. The Mackenzie Delta - Yukon Coastal Plain region of the Western Canadian Arctic (Figure 1) is potentially one of the most sensitive permafrost areas in Canada. The combination of widespread ground ice, relatively moderate climate and the predicted magnitude of warming suggest that this area will change dramatically in the next 100 years. The iterative effect of climate change will involve warming permafrost, increased active layer depth, increased thermokarst, thinning sea ice, longer open water, increased storm activity, rising sea levels and accelerated coastal erosion. The synergy of these changes will produce an outcome that far exceeds impacts expected for other Arctic regions. The research presented here aims to assess and map the sensitivity of Arctic coastal environments. Focusing on the Beaufort Sea coast, we employ (1) morphological methods to estimate ground ice content, and (2) remote sensing technologies to observe surficial changes in coastline conditions reflecting permafrost degradation. More specifically, refinements have been made to the morphoiogicai method for assessing ground ice content and a larger, additional region of coastline has been evaluated. Secondly, we have begun exploring various remote sensing and GPS tools as a means of monitoring retrogressive thaw slump erosion in this region. (Au)

A, C, E, D
Active layer; Aerial photography; Beach erosion; Climate change; Coast changes; Coasts; Geographical positioning systems; Ground ice; Ice wedges; Permafrost; Satellite photography; Sea level; Temporal variations; Thaw flow slides; Thawing; Thermokarst

G0811, G0812
Herschel Island, Yukon; King Point, Yukon; Komakuk Beach, Yukon; Kugmallit Bay region, N.W.T.; Mackenzie Delta, Yukon


Research report : dendrochronological potential of Salix alaxensis from the Kuujjua River area, western Canadian Arctic   /   Zalatan, R.   Gajewski, K.
(Tree-ring research, v. 62, no. 2, Dec. 2006, p. 75-82, ill., maps)
(PCSP/PPCP contribution, no. 047-04)
References.
ASTIS record 76131.
Languages: English
Web: doi:10.3959/1536-1098-62.2.75
Libraries: ACU

This study presents the first annually-resolved chronology using Salix alaxensis (Anderss.) Cov from Victoria Island, Northwest Territories, Canada, an area well north of treeline. Forty-one samples were collected and examined for subsequent analysis. However, crossdating was difficult because of locally absent or missing rings and the narrowness of the rings, and ultimately thirteen stems were crossdated and used to evaluate their dendroclimatological potential. The chronology spans 74 years (1927-2000) and could potentially be extended further using subfossil wood. Precipitation data from December of the previous year to March of the current year were the most consistently and highly correlated with ring width. This suggests that the recharge of the soil moisture by early summer snowmelt is a key factor limiting growth of these shrubs. (Au)

H, C, F, E
Climate change; Dendrochronology; Effects of climate on plants; Growing season; Meteorology; Plant growth; Plant-soil relationships; Plant-water relationships; Seasonal variations; Shrubs; Snowmelt; Soil moisture; Stems; Temporal variations; Weather stations; Willows

G0812
Kuujjua River region, N.W.T.


Limnology of 46 lakes and ponds on Banks Island, N.W.T., Canadian Arctic Archipelago   /   Lim, D.S.S.   Douglas, M.S.V.   Smol, J.P.
(Hydrobiologia, v.545, no. 1, Aug. 2005, p. 11-32, ill., maps)
(PCSP/PPCP contribution, no. 048-04)
References.
ASTIS record 73759.
Languages: English
Web: doi:10.1007/s10750-005-1824-7
Libraries: ACU

The goal of this study was to describe and quantify the physical and chemical limnological properties of 46 lakes and ponds on Banks Island, to explore the effects of ecoclimatic differences on the water chemistry of these study sites, and to establish baseline conditions for this previously unexplored limnological region, which could then be used in subsequent long-term environmental monitoring programs. A key finding was that the study sites on Banks Island represented a large nutrient concentration gradient from ultra-oligotrophic to hypereutrophic waters. In general, the study sites were relatively nutrient rich by Arctic standards (i.e. mean total nitrogen (TNmean)=504.2µg/l and mean total phosphorus (TPUmean)=18.0µg/l); concentrations that are amongst the highest of any previous limnological survey from similar latitudes. Dissolved organic carbon (DOC) concentrations were also some of the highest reported to date amongst all other Canadian Arctic island limnological surveys. These values reflect the milder climate, concentrated animal life and lushness of Banks Island, as compared to other Canadian Arctic Archipelago islands. Principal components analysis (PCA) separated sites along a conductivity/ionic and elevation gradient on Axis 1 (lambda1=0.343), and a metal (Fe, Zn, Al) and alkalinity-related (DIC, pH) gradient on the second axis (lambda2=0.187). Canonical variate analysis (CVA) was used to explore the classification of the study sites into Low Arctic, Mid Arctic or High Arctic designations based on their limnological characteristics. (Au)

F, B, E, J, I
Animal distribution; Animal population; Atmospheric temperature; Bathymetry; Carbon; Chemical properties; Chlorophyll; Climate change; Dissolved organic carbon; Effects monitoring; Electrical properties; Fresh-water biology; Fresh-water ecology; Geology; Heavy metals; Lakes; Metals; Nitrogen; Numeric databases; Oligotrophic lakes; Phosphorus; Plant distribution; Suspended solids; Taiga ecology; Temperature; Temporal variations; Trace elements; Tundra ponds; Water pH

G0812, G0813
Banks Island, N.W.T.; Canadian Arctic Islands


Organic geochemical characterization of a Miocene core sample from Haughton impact structure, Devon Island, Nunavut, Canadian High Arctic   /   Eglinton, L.B.   Lim, D.   Slater, G.   Osinski, G.R.   Whelan, J.K.   Douglas, M.
(Organic geochemistry, v. 37, no. 6, June 2006, p. 688-710, ill., maps)
(PCSP/PPCP contribution, no. 049-04)
References.
ASTIS record 59666.
Languages: English
Web: doi:10.1016/j.orggeochem.2006.01.006
Libraries: ACU

Extremely well preserved sedimentary deposits in the Haughton impact structure (HIS) provide a unique record of the post-impact Miocene lacustrine depositional environment. Detailed organic geochemical characterization of a hydrocarbon-impregnated band found in a core from the crater-lake sedimentary infill reveals a complex source history for the hydrocarbons. These include contributions from eroded pre- and post-impact formations together with inputs from contemporaneous flora and fauna, a deep, possibly lower Paleozoic petroleum as well as a contribution from hydrothermally altered organic biopolymers. Geochemical data coupled with paleolimnology and geology proves to be a valuable tool for studying the provenance of hydrocarbons associated with the HIS and can give insights, not only into the post-impact geology, but also into processes that may contribute to the generation of petroleum fluids at other impact sites. (Au)

B, A, P, Q, H, I, F
Bottom sediments; Chromatography; Cores; Craters; Economic geology; Fresh-water biology; Geochemical exploration; Geochemistry; Hydrocarbons; Isotopes; Lakes; Miocene epoch; Ore deposits; Palaeobotany; Palaeogeography; Palaeontology; Palaeozoic era; Palynology; Petroleum geology; Sedimentary rocks; Sedimentation

G0813
Haughton Crater, Nunavut


Early-20th century environmental changes inferred using subfossil diatoms from a small pond on Melville Island, N.W.T., Canadian High Arctic   /   Keatley, B.E.   Douglas, M.S.V.   Smol, J.P.
(Hydrobiologia, v.553, no. 1, Jan. 2006, p. 15-26, ill., maps)
(PCSP/PPCP contribution, no. 050-04)
References.
ASTIS record 73761.
Languages: English
Web: doi:10.1007/s10750-005-1737-5
Libraries: ACU

Diatom-based paleolimnological studies are being increasingly used to track long-term environmental change in arctic regions. Little is known, however, about the direction and nature of such environmental changes in the western Canadian high Arctic. In this study, shifts in diatom assemblages preserved in a 210Pb-dated sediment core collected from a small pond on Melville Island, N.W.T., were interpreted to record marked environmental changes that had taken place since the early 20th century. For most of the history of the pond recorded in this core, the diatom assemblage remained relatively stable and was dominated by Fragilaria capucina. A major shift in species composition began in the early-20th century, with a sharp decline in F. capucina and a concurrent increase in Achnanthes minutissima. In the last ~20 years, further changes in the diatom assemblage occurred, with a notable increase in the Nitzschia perminuta complex. The assemblage shifts recorded at this site appear to be consistent with environmental changes triggered by recent climatic warming. (Au)

F, B, H, E, J
Bathymetry; Bottom sediments; Climate change; Cores; Diatoms; Effects monitoring; Effects of climate on plants; Electrical properties; Fresh-water biology; Fresh-water ecology; Growing season; Ice cover; Lakes; Mass spectrometry; Nitrogen; Palaeoclimatology; Palaeoecology; Sedimentation; Taiga ecology; Temporal variations; Tundra ponds; Water pH

G0812, G0813
Melville Island, N.W.T./Nunavut; Queen Elizabeth Islands, N.W.T./Nunavut


Marine birds of the Hell Gate Polynya, Nunavut, Canada   /   Mallory, M.L.   Gilchrist, H.G.
(Polar research, v. 24, no. 1-2, July 2005, p. 87-93, maps)
(PCSP/PPCP contribution, no. 051-04)
References.
ASTIS record 61084.
Languages: English
Web: doi:10.1111/j.1751-8369.2005.tb00142.x
Libraries: ACU

The importance of the Hell Gate Polynya to marine birds in High Arctic Canada has not been assessed for two decades. Our breeding season surveys in 2002-04 found 19 species of marine birds using the polynya, in annual numbers perhaps reaching 25000 individuals. The site appears to support nationally significant populations of northern fulmar (Fulmarus glacialis), Thayer's gull (Larus thayeri) and High Arctic brant (Branta bernida hrota), as well as locally important numbers of other species including common eiders (Somateria mollissima borealis) and black guillemots (Cepphus grylle). The polynya may be particularly important for migration, as many species are observed here earlier than elsewhere in the High Arctic. (Au)

I, D, J
Aerial surveys; Animal distribution; Animal migration; Animal population; Bird nesting; Black Guillemots; Brant; Common Eiders; Environmental protection; Environmentally significant areas; Fulmars; Polynyas; Sea birds; Thayer's Gulls; Wildlife habitat

G0813, G0815
Calf Island, Nunavut; Devil Island, Nunavut; Hell Gate (76 42 N, 89 44 W), Nunavut; Olsen Island, Nunavut; Penny Strait region, Nunavut; Penny Strait, Nunavut; St. Helena Island, Nunavut; Vera, Cape, Nunavut


Walrus (Odobenus rosmarus) predation on adult Thick-billed Murres (Uria lomvia) at Coats Island, Nunavut, Canada   /   Mallory, M.L.   Woo, K.   Gaston, A.J.   Davies, W.E.   Mineau, P.
(Polar research, v. 23, no. 1, June 2004, p. 111-114, 1 map)
(PCSP/PPCP contribution, no. 054-04)
References.
ASTIS record 57348.
Languages: English
Web: doi:10.1111/j.1751-8369.2004.tb00133.x
Libraries: ACU

Although the diet of walrus (Odobenus rosmarus) is considered varied, records of walrus consuming marine birds are rare in the published literature. In 2001 and 2002 we observed walrus foraging on adult thick-billed murres (Uria lomvia) at Coats Island in Nunavut, Canada. Approximately 46% of the attacks on murres were successful, and as many as 67 murres may have been killed in one day in August 2002. All soft parts of the murres were sucked out, with carcasses of only bones, feathers and skin left floating on the water. The extent to which predation on seabirds by walrus occurs across the eastern Arctic is unknown, but it could represent an important source of mortality for murres at some breeding colonies. (Au)

I, J, T
Animal behaviour; Animal food; Animal mortality; Fishes; Inuit; Predation; Sea birds; Seals (Animals); Thick-billed Murres; Traditional knowledge; Trophic levels; Walruses; Whales

G0814
Coats Island waters, Nunavut; Hudson Bay


Trace elements and halogenated organic compounds in Canadian Arctic seabirds   /   Braune, B.M.   Simon, M.
(Marine pollution bulletin, v. 48, no. 9-10, May 2004, p. 986-992, maps)
(PCSP/PPCP contribution, no. 055-04)
References.
ASTIS record 53564.
Languages: English
Web: doi:10.1016/j.marpolbul.2004.02.018
Libraries: ACU

The objective of this study was to identify trace elements and halogenated organic compounds in livers and eggs of Canadian Arctic seabirds which are outside of the normal suite of contaminants routinely monitored. Adult northern fulmars (Fulmaris glacialis), blacklegged kittiwakes (Rissa tridactyla), and thick-billed murres (Uria lomvia) were collected from the Prince Leopold Island Migratory Bird Sanctuary (74°02'N, 90°05'W) in Lancaster Sound, Nunavut, Canada ... during 1975 and 1993. ... Pooled samples of liver and egg homogenates were analyzed for the following 24 essential and non-essential elements: aluminum (Al), antimony (Sb), arsenic (As), barium (Ba), beryllium (Be), boron (B), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), molybdenum (Mo), nickel (Ni), selenium (Se), silver (Ag), strontium (Sr), thallium (Tl), tin (Sn), uranium (U), vanadium (V), and zinc (Zn). ... GC/MS total ion chromatography (TIC) was used to confirm the presence and to estimate the levels of toxaphene, polybrominated diphenyl ethers (PBDEs), polychlorinated diphenyl ethers (PCDEs), polychlorinated terphenyls (PCTs), polybrominated biphenyls (PBBs), polychlorinated naphthalenes (PCNs), tris(chlorophenyl)methane (TCP-methane), tris(4-chlorophenyl)methanol (TCP-methanol) and halogenated dimethyl bipyrroles (HDBPs) .... Toxaphene was detected in every Arctic seabird sample (both eggs and livers) analyzed in this study, except for the pool of kittiwake livers from 1975 .... The highest estimated level of toxaphene was found in the pool of kittiwake eggs from 1993 followed by the 1993 pool of fulmar eggs. These data suggest that exposure to toxaphene increased from 1975 to 1993. ... Total PBDEs were present at low ng/g levels in most of the samples of Arctic seabirds analyzed in this study .... PCTs were detected in all samples except the 1993 thickbilled murre liver and egg samples .... HDBPs were detected in all egg and liver samples from 1993 but only in the kittiwake liver sample from 1975 .... Trace amounts (<2 ng/g ww) of TCP-methane and a hexabromo biphenyl (HxBB) were identified and confirmed in most of the seabird samples. TCP-methane was detected in 1975 kittiwake livers > 1993 kittiwake eggs > 1993 fulmar eggs. No PCDEs, TCP-methanol or PCNs were detected in any of the seabird samples. ... Overall, the highest concentrations of toxaphene, PBDEs and HDBPs were found in the kittiwake eggs collected in 1993, and the greatest concentrations of PCTs were found in the 1975 kittiwake livers and the 1993 kittiwake eggs. Clearly, most of the quantifiable or detected concentrations of the halogenated organic compounds measured were found in the kittiwake samples followed, in most cases except for PBDEs, by the fulmar samples. ... There is no indication that concentrations of any of the halogenated organic compounds measured in this study are causing toxicological effects in these species. Concentrations of Ag (0.12), Al (2.5), B (1.5), Ba (1.5), Be (1.5), Co (0.2), Ni (0.5), Pb (0.18), Sb (0.5), Tl (0.02), U (0.02), and V (0.5) were below the detection limit (given in brackets as mg/kg ww) for all samples. Detectable concentrations of Cu, Fe, Hg, Se and Zn were found in all of the samples analyzed, whereas As, Cd, Cr, Mn, Mo, Sn and Sr were detected in only some of the samples .... Of those elements detected, As, Cd, Cr, Mn, Mo and Sn were not found in any of the egg samples whereas Cu, Fe, Hg, Se, Sr and Zn were found in all of the eggs. ... Of the major heavy metals of concern in birds, concentrations of both Hg and Cd were highest in northern fulmars, whereas Pb was not detected in any of the Arctic seabird samples analyzed. ... (Au)

J, I
Animal mortality; Bioaccumulation; Biological sampling; Biomagnification; Bird nesting; Chlorophenols; Chromatography; Copper; Dioxins; Effects monitoring; Environmental impacts; Fulmars; Furans; Heavy metals; Internal organs; Iron; Kittiwakes; Mass spectrometry; Measurement; Mercury; Organobromines; Organochlorines; PCBs; Pollution; Selenium; Temporal variations; Thick-billed Murres; Toxaphene; Toxicity; Trace elements; Zinc

G0813
Prince Leopold Island Migratory Bird Sanctuary, Nunavut


Benthic and planktonic algal communities in a High Arctic lake : pigment structure and contrasting responses to nutrient enrichment   /   Bonilla, S.
(Journal of phycology, v. 41, no. 6, Dec. 2005, p.1120-1130, ill.)
(PCSP/PPCP contribution, no. 001-05)
References.
ASTIS record 61117.
Languages: English
Web: doi:10.1111/j.1529-8817.2005.00154.x
Libraries: ACU

We investigated the fine pigment structure and composition of phytoplankton and benthic cyanobacterial mats in Ward Hunt Lake at the northern limit of High Arctic Canada and the responses of these two communities to in situ nutrient enrichment. The HPLC analyses showed that more than 98% of the total pigment stocks occurred in the benthos. The phytoplankton contained Chrysophyceae, low concentrations of other protists and Cyanobacteria (notably picocyanobacteria), and the accessory pigments chl c2, fucoxanthin, diadinoxanthin, violaxanthin, and zeaxanthin. The benthic community contained the accessory pigments chl b, chl c2, and a set of carotenoids dominated by glycosidic xanthophylls, characteristic of filamentous cyanobacteria. The black surface layer of the mats was rich in the UV-screening compounds scytonemin, red scytonemin-like, and mycosporine-like amino acids, and the blue-green basal stratum contained high concentrations of light-harvesting pigments. In a first bioassay of the benthic mats, there was no significant photosynthetic or growth response to inorganic carbon or full nutrient enrichment over 15 days. This bioassay was repeated with increased replication and HPLC analysis in a subsequent season, and the results confirmed the lack of significant response to added nutrients. In contrast, the phytoplankton in samples from the overlying water column responded strongly to enrichment, and chl alpha biomass increased by a factor of 19.2 over 2 weeks. These results underscore the divergent ecophysiology of benthic versus planktonic communities in extreme latitudes and show that cold lake ecosystems can be dominated by benthic phototrophs that are nutrient sufficient despite their ultraoligotrophic overlying waters. (Au)

H, F, E, J
Algae; Amino acids; Benthos; Bioassays; Biological productivity; Biomass; Carbon cycling; Cold adaptation; Cyanophyceae; Food chain; Fresh-water ecology; Light; Nitrogen; Oligotrophic lakes; Phosphorus; Photosynthesis; Phytoplankton; Plant growth; Plant nutrition; Plant physiology; Plant taxonomy; Seasonal variations

G0813
Meretta Lake, Nunavut; Quttinirpaaq National Park, Nunavut; Ward Hunt Island, Nunavut


Lake-bottom thermal regimes, western Arctic coast, Canada   /   Burn, C.R.
(Permafrost and periglacial processes, v. 16, no. 4, Oct./Dec. 2005, p. 355-367, ill., map)
(PCSP/PPCP contribution, no. 003-05)
References.
ASTIS record 62622.
Languages: English
Web: doi:10.1002/ppp.542
Libraries: ACU

Lake-bottom temperatures have been measured for several years at two lakes with littoral terraces on north-central Richards Island, a residual pond of the Illisarvik experimental drained lake site, and a taiga lake near Inuvik. The tundra lakes possess distinct thermal regimes: in (1) the deep central pools; (2) shallows where winter ice may reach bottom; and (3) on littoral terraces, where water depth is less than 1 m. In summer, the tundra lakes are uniformly well mixed and reach similar lake-bottom temperatures at all depths. In winter, conditions vary, depending on the proximity of the ice cover to lake bottom. The annual mean lake-bottom temperatures have been about 3°C in the deep central pools, 0°C in the shallow pools, and -2°C on the terraces of the tundra lakes. For the taiga lake, where late-winter ice cover reaches only about half the thickness of the two tundra lakes, annual lake-bottom temperatures follow the same pattern as in the central pools of the tundra lakes, but the mean temperature is over 5°C. If the thermal regime of the taiga lake is an analogue for tundra conditions following climate warming, then the width of lakes with through taliks on Richards Island may decline by between 20 and 100 m. At equilibrium, about 45% of the lakes and 20% of the surface area of Richards Island may then be underlain by taliks that penetrate permafrost. (Au)

C, F, G, E, J
Atmospheric temperature; Bathymetry; Bottom sediments; Climate change; Effects monitoring; Effects of climate on permafrost; Frozen ground; Groundwater; Heat transmission; Ice cover; Interstitial water; Lake ice; Lakes; Permafrost beneath lakes; Seasonal variations; Snow; Soil temperature; Taiga ecology; Temperature; Temporal variations; Thermal properties; Thermal regimes; Tundra ecology; Tundra ponds

G0812
Illisarvik Lake, N.W.T.; Inuvik region, N.W.T.; Richards Island, N.W.T.; Tuktoyaktuk, N.W.T.


Subglacial drainage processes at a High Arctic polythermal valley glacier   /   Bingham, R.G.   Nienow, P.W.   Sharp, M.J.   Boon, S.
(Journal of glaciology, v. 51, no.172, 2005, p. 15-24, ill., maps)
(PCSP/PPCP contribution, no. 004-05)
References.
ASTIS record 61088.
Languages: English
Web: doi:10.3189/172756505781829520
Libraries: ACU

Dye-tracer experiments undertaken over two summer melt seasons at polythermal John Evans Glacier, Ellesmere Island, Canada, were designed to investigate the character of the subglacial drainage system and its evolution over a melt season. In both summers, dye injections were conducted at several moulins and traced to a single subglacial outflow. Tracer breakthrough curves suggest that supraglacial meltwater initially encounters a distributed subglacial drainage system in late June. The subsequent development and maintenance of a channelled subglacial network are dependent upon sustained high rates of surface melting maintaining high supraglacial inputs. In a consistently warm summer (2000), subglacial drainage became rapidly and persistently channelled. In a cooler summer (2001), distributed subglacial drainage predominated. These observations confirm that supraglacial meltwater can access the bed of a High Arctic glacier in summer, and induce significant structural evolution of the subglacial drainage system. They do not support the view that subglacial drainage systems beneath polythermal glaciers are always poorly developed. They do suggest that the effects on ice flow of surface water penetration to the bed of predominantly cold glaciers may be short-lived. (Au)

F, E, J, D
Climate change; Detection; Drainage; Dyeing; Effects of climate on ice; Flow; Glacial melt waters; Glaciers; Hydrology; Ice sheets; Mathematical models; Measurement; River discharges; Sea level; Seasonal variations; Storage; Temporal variations; Valleys; Velocity

G0813
John Evans Glacier, Nunavut


The influence of thermokarst disturbance on the water quality of small upland lakes, Mackenzie Delta region, Northwest Territories, Canada   /   Kokelj, S.V.   Jenkins, R.E.   Milburn, D.   Burn, C.R.   Snow, N.
(Permafrost and periglacial processes, v. 16, no. 4, Oct./Dec. 2005, p. 343-353, ill., maps)
(PCSP/PPCP contribution, no. 006-05)
References.
ASTIS record 62623.
Languages: English
Web: doi:10.1002/ppp.536
Libraries: ACU

Chemical data are presented for water from 22 lakes in small upland catchments (< 20 ha) between Inuvik and Richards Island, Northwest Territories, Canada. Eleven of the basins appear pristine and 11 are affected by thermokarst slumping. The mean dissolved organic carbon (DOC) concentration of the pristine lakes (16.3 mg/l) is greater than the mean concentration of lakes disturbed by thermokarst slumping (10.5 mg/l). In pristine lakes, mean concentrations of Ca, Mg and SO4 are 9.6, 3.6 and 11.1 mg/l, but in lakes affected by thermokarst, mean concentrations are 72.6, 26.8 and 208.2 mg/l, respectively. Soluble materials released from degrading permafrost are transported to lakes by surface runoff, elevating concentrations in lake water. The percentage of total basin area influenced by thermokarst is positively associated with ionic concentrations in lake water and inversely related to DOC. Thermokarst occupying as little as 2% of catchment area may modify the chemistry of lake water, and water quality may remain affected for several decades after slump development has ceased. Aerial photographs indicate that 5 to 15% of all lakes and ponds in four 49 km² areas between Inuvik and Richards Island are small (median size < 2 ha) with catchments affected by thermokarst. (Au)

C, A, F, E, J
Aerial photography; Carbon; Chemical properties; Climate change; Dissolved organic carbon; Effects monitoring; Electrical properties; Fire ecology; Measurement; Melting; Optical properties; Permafrost; Runoff; Salinity; Slopes; Snowmelt; Soil chemistry; Soils; Sulphates; Thaw flow slides; Thermal properties; Thermokarst; Topography; Tundra ponds; Water quality; Watersheds

G0812
Inuvik region, N.W.T.; Jimmy Lake, N.W.T.; Mackenzie Delta, N.W.T.; Noell Lake region, N.W.T.; Noell Lake, N.W.T.; Parsons Lake region, N.W.T.; Parsons Lake, N.W.T.; Richards Island, N.W.T.


Near-surface ground ice in sediments of the Mackenzie Delta, Northwest Territories, Canada   /   Kokelj, S.V.   Burn, C.R.
(Permafrost and periglacial processes, v. 16, no. 3, July/Sept. 2005, p. 291-303, ill., maps)
(PCSP/PPCP contribution, no. 007-05)
References.
ASTIS record 62624.
Languages: English
Web: doi:10.1002/ppp.537
Libraries: ACU

The ice content of near-surface permafrost was determined at more than 70 sites in the Mackenzie Delta, Northwest Territories. Willow and alder communities growing on aggrading surfaces with well-drained sandy silts and warm ground temperatures were underlain by permafrost with low ice content. Spruce forests above the level of annual flooding, lakeside alder communities in the central and southern delta, and sedge wetlands in the northern delta with moist silty loam soils, low sedimentation rates and cold ground temperatures were underlain by medium to high ice-content permafrost. Beneath spruce forests, a layer of near-surface ice accumulation 1 to 2 m thick was underlain by alluvium bonded by pore ice. These profiles indicate that contemporary conditions favour near-surface ice accumulation. The preservation of ice-poor permafrost at depth demonstrates the limited vertical accumulation of near-surface segregated ice. In contrast, at lakeshore alder or sedge wetlands, segregated ice extended at least 2 m below the base of the active layer, indicating that permafrost aggraded in a saturated environment. Development of ground ice in the Mackenzie Delta may elevate alluvial surfaces, modify the flooding regime, and thereby influence soil conditions and ecological succession. (Au)

C, H, E, B, J, F, G
Accumulation; Active layer; Alders; Bearberry; Breakup; Climate change; Cores; Drainage; Ecology; Effects of climate on permafrost; Environmental impacts; Floods; Frozen ground; Geochemistry; Ground ice; Lakes; Lichens; Mathematical models; Moisture transfer; Mosses; Permafrost; Plant distribution; Plant growth; Plant nutrition; Plant succession; Plant-soil relationships; Plant-water relationships; River deltas; River ice; Rivers; Seasonal variations; Sedges; Sedimentation; Sediments (Geology); Shorelines; Shrubs; Snowfall; Soil chemistry; Soil moisture; Soil temperature; Spruces; Thermal regimes; Wetlands; Willows

G0812
Aklavik region, N.W.T.; East Channel (Mackenzie River) region, N.W.T.; East Channel (Mackenzie River), N.W.T.; Ellice Island, N.W.T.; Inuvik region, N.W.T.; Mackenzie Delta, N.W.T.; Reindeer Station region, N.W.T.


An extreme sediment transfer event in a Canadian High Arctic stream   /   Lewis, T.   Braun, C.   Hardy, D.R.   Francus, P.   Bradley, R.S.
(Arctic, antarctic, and alpine research, v. 37, no. 4, Nov. 2005, p. 477-482, ill., maps)
(PCSP/PPCP contribution, no. 008-05)
References.
PARCS (Paleoenvironmental Arctic Sciences) contribution no. 235.
ASTIS record 60296.
Languages: English
Web: doi:10.1657/1523-0430(2005)037[0477:AESTEI]2.0.CO;2
Libraries: ACU

Two large suspended sediment concentration (SSC) pulses were recorded in 1998 in a small snowmelt-fed stream on Ellesmere Island in the Canadian High Arctic. The largest pulse occurred from 7 to 8 July, when 32% of the monitored seasonal sediment transport occurred in only four hours. SSC reached 83,760 mg/L, exceeding all previously recorded values from high arctic glacially-fed and snowmelt-fed rivers by more than one order of magnitude. The event occurred after the majority of snow in the watershed had melted, and was preceded by a long period of relatively high air temperature, and a small rainfall event on 7 July. We consider the most likely cause of the event to be a rapid mass movement. ... In this note, we present a high-resolution hydrometeorological record for most of the 1998 melt season from the main river that drains into snowmelt-fed South Sawtooth Lake (SSL; unofficial name; 79.3°N, 83.9°W). ... (Au)

F, A, E, C
Atmospheric temperature; Drainage; Effects monitoring; Electrical properties; Hydrology; Lakes; Mass wasting; Measurement; Meteorology; Permafrost; Precipitation (Meteorology); River discharges; Rivers; Runoff; Sediment transport; Snowmelt; Snowpatches; Stream flow; Suspended solids; Temporal variations; Thawing; Water level; Watersheds; Weather stations

G0813
Eureka, Nunavut; Fosheim Peninsula, Nunavut


Microbial habitat dynamics and ablation control on the Ward Hunt Ice Shelf   /   Mueller, D.R.   Vincent, W.F.
(Hydrological processes, v. 20, no. 4, 15 Mar. 2006, p. 857-876, ill., maps)
(PCSP/PPCP contribution, no. 010-05)
References.
ASTIS record 74123.
Languages: English
Web: doi:10.1002/hyp.6113
Libraries: ACU

The Ward Hunt Ice Shelf (83°02'N, 74°00'W) is an ~40 m thick ice feature that occupies a large embayment along Canada's northernmost coast. Sediments cover 10% of its surface and provide a habitat for diverse microbial communities. These assemblages form an organo-sedimentary matrix (microbial mat) composed of cold-tolerant cyanobacteria and several other types of organisms. We investigated the environmental properties (temperature, irradiance, conductivity and nutrient concentration) of the microbial mat habitat and the effect of the microbial mats on the surface topography of the ice shelf. The low albedo of microbial mats relative to the surrounding snow and ice encouraged meltwater production, thereby extending the growth season to 61 days despite only 52 days with mean temperatures above 0 °C. We found large excursions in salinity near the microbial mat during freeze-up and melt, and 54% of all ponds sampled had conductivity profiles indicating stratification. Nutrient concentrations within the microbial mats were up to two orders of magnitude higher than those found in the water column, which underscores the differences between the microbial mat microenvironment and the overall bulk properties of the cryo-ecosystem. The average ice surface ablation in the microbial mat-rich study site was 1.22 m/year, two times higher than values measured in areas of the ice shelf where mats were less prevalent. We demonstrate with topographic surveys that the microbial mats promote differential ablation and conclude that the cohesive microbial aggregates trap and stabilize sediment, reduce albedo, and thereby influence the surface morphology of the ice shelf. (Au)

H, J, F, A, E, G
Albedo; Algae; Atmospheric temperature; Bacteria; Biological sampling; Carbon; Cyanophyceae; Diatoms; Electrical properties; Firn; Ice shelves; Isotopes; Lake stratification; Mass balance; Melting; Microbial ecology; Microclimatology; Microorganisms; Nitrogen; Oxygen; Phosphorus; Plant growth; Plant nutrition; Primary production (Biology); Puddles; Salinity; Sea ice; Sediments (Geology); Snow; Snow; Snowmelt; Solar radiation; Temperature; Topography; Velocity; Water pH; Winds

G0813, G03
Markham Fiord, Nunavut; Ward Hunt Ice Shelf, Nunavut


The Innuitian Ice Sheet : configuration, dynamics and chronology   /   England, J.   Atkinson, N.   Bednarski, J.   Dyke, A.S.   Hodgson, D.A.   Cofaigh, C.Ó.
(Quaternary science reviews, v. 25, no. 7-8, Apr. 2006, p. 689-703, maps)
(PCSP/PPCP contribution, no. 011-05)
References.
ASTIS record 60281.
Languages: English
Web: doi:10.1016/j.quascirev.2005.08.007
Libraries: ACU

Portrayal of North American ice cover during the Last Glacial Maximum is dominated by the Laurentide Ice Sheet, leaving little detail for the adjacent Innuitian Ice Sheet (IIS). Four decades of geological fieldwork across the Queen Elizabeth Islands now warrant specific treatment of the IIS, including its chronology, configuration, dynamics and retreat. This reconstruction is relevant to the sedimentary history of the Arctic Ocean and to high latitude climate forcing. The IIS was composed of both an alpine and lowland sector. The advance of the alpine sector occurred as recently as 19 14Cka BP. Geological evidence configures outflow from alpine and lowland divides that produced several palaeo-ice streams, one extending northwestward across the Canadian Arctic Archipelago to the polar continental shelf. Retreat of the IIS commenced along its southwest margin ~11.6 14Cka BP. However, most of the ice sheet remained on the continental shelf during the Younger Dryas. By ~10 14Cka BP, marine-based ice experienced widespread calving through the western and central archipelago in response to Holocene warming and ongoing eustatic sea level rise. The sea penetrated the eastern archipelago by 8.5 14Cka BP, gutting the alpine sector of the IIS. Regional isobases record the glacioisostatic signature of the ice sheet, and are congruent with the primary geological evidence. The delayed buildup of the IIS was out-of-phase with the growth of the Laurentide Ice Sheet that occasioned climatic and glacio-eustatic forcing in the Innuitian region. Recent modelling experiments reinforce the hypothesis that growth of the Laurentide Ice Sheet culminated in a split jet stream that temporarily favoured augmented precipitation and growth of the IIS. (Au)

A, B, F, D, E
Deglaciation; Effects of ice on climate; Flow; Glacial epoch; Glacial geology; Glacial landforms; Glacial melt waters; Glaciation; Ice caps; Ice cover; Ice divides; Ice sheets; Laurentide Ice Sheet; Mathematical models; Ocean-atmosphere interaction; Palaeogeography; Precipitation (Meteorology); Radiocarbon dating; Recent epoch; Sea level; Sedimentation; Sediments (Geology); Stratigraphy

G0813, G0812, G0815, G03
Amund Ringnes Island waters, Nunavut; Amund Ringnes Island, Nunavut; Arctic Ocean; Axel Heiberg Island, Nunavut; Baillie-Hamilton Island, Nunavut; Beechey Island, Nunavut; Belcher Channel, Nunavut; Cornwallis Island, Nunavut; Devon Island, Nunavut; Ellef Ringnes Island waters, Nunavut; Ellef Ringnes Island, Nunavut; Ellesmere Island, Nunavut; Eureka Sound, Nunavut; Meighen Island, Nunavut; Melville Island, N.W.T./Nunavut; Nansen Sound, Nunavut; Nares Strait, Greenland/Nunavut; Norwegian Bay, Nunavut; Prince Patrick Island, N.W.T.; Queen Elizabeth Islands, N.W.T./Nunavut; Wellington Channel, Nunavut


Environmental gradients, fragmented habitats, and microbiota of a northern ice shelf cryoecosystem, Ellesmere Island, Canada   /   Mueller, D.R.   Vincent, W.F.   Jeffries, M.O.
(Arctic, antarctic, and alpine research, v. 38, no. 4, Nov. 2006, p. 593-607, ill., maps)
(PCSP/PPCP contribution, no. 014-05)
References.
ASTIS record 74026.
Languages: English
Web: doi:10.1657/1523-0430(2006)38[593:EGFHAM]2.0.CO;2
Libraries: ACU

Over the course of the last century, the 9000-km² "Ellesmere Ice Shelf" (82-83°N, 64-90°W) fragmented into six main ice shelves now totaling 1043 km². This ensemble of thick ice environments lies along the northern coast of Ellesmere Island in the Canadian High Arctic and provides a cryohabitat for microbial communities that occur in association with eolian and glacially entrained sediments on the ice surface. We undertook a comparative analysis of physical, chemical, and biological characteristics of five of the remnant ice shelves including geographic information system (GIS) mapping of ice types. Each of these remnants is a thick (>20 m) mass of ice with substantial sediment overburden that promotes the formation of oligotrophic meltwaters in the summer. Microbiota occurred in all sampled sediment, forming a continuum of abundance from sparse to loosely cohesive and pigmented microbial mats. Using digital images from over-flight transects we determined that 8% of the combined ice-shelf area was suitable microbial mat habitat, and contained an estimated 34 Gg of organic matter stocks for the entire system. A gradient of increasing chlorophyll a, organic content, and conductivity was found from west to east. This is likely related to the surface ice type (meteoric versus marine) and to the relative availability of sediment. Our results indicate that differences in phototrophic community structure (microalgae and cyanobacterial morphotypes) were associated with different ice and microbial mat types. In addition, the relative abundance of dominant taxa was significantly associated with environmental gradients of conductivity, soluble reactive phosphorus, and nitrate and ammonium concentrations. There were distinct differences between each ice shelf with regards to ice type and sediment availability but no differences in taxonomic richness or diversity, indicating little effect of habitat fragmentation on these community attributes. However, the ensemble of ice shelves that compose this unique cryoecosystem remains vulnerable to habitat attrition and complete loss with ongoing climate warming. (Au)

F, B, H, J, I, A
Algae; Biological sampling; Biomass; Carbon; Chlorophyll; Cyanophyceae; Electrical properties; Firn; Geographic information systems; Glacial melt waters; Glacial transport; Glaciers; Ice rises; Ice shelves; Identification; Mapping; Microbial ecology; Microorganisms; Nitrogen; Phosphorus; Plankton; Plant nutrition; Primary production (Biology); Puddles; SAR; Satellite photography; Sediments (Geology); Size; Snow; Snowmelt; Temperature; Water pH

G0813, G03
Ayles Fiord, Nunavut; Markham Fiord, Nunavut; Milne Ice Shelf, Nunavut; Petersen Bay, Nunavut; Serson Ice Shelf, Nunavut; Ward Hunt Ice Shelf, Nunavut


Coupled landscape-lake evolution in High Arctic Canada   /   Van Hove, P.   Belzile, C.   Gibson, J.A.E.   Vincent, W.F.
(Canadian journal of earth sciences, v. 43, no. 5, May 2006, p. 533-546, ill., maps)
(PCSP/PPCP contribution, no. 016-05)
References.
French abstract provided.
ASTIS record 60623.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/193.pdf
Web: doi:10.1139/E06-003
Libraries: ACU

We profiled five ice-covered lakes and two ice-covered fiords of Ellesmere Island at the northern limit of High Arctic Canada to examine their environmental characteristics, and to evaluate the long-term limnological consequences of changes in their surrounding landscape through time (landscape evolution). All of the ecosystems showed strong patterns of thermal, chemical, and biological stratification with subsurface temperature maxima from 0.75 to 12.15 °C; conductivities up to 98.1 mS/cm (twice that of seawater) in some bottom waters; pronounced gradients in nitrogen, phosphorus, pH, dissolved inorganic and organic carbon, manganese, iron, and oxygen; and stratified photosynthetic communities. These ecosystems form an inferred chronosequence that reflects different steps of landscape evolution including marine embayments open to the sea, inlets blocked by thick sea ice (Disraeli Fiord, Taconite Inlet), perennially ice-capped, saline lakes isolated from the sea by isostatic uplift (Lakes A, C1, C2), and isolated lakes that lose their ice cover in summer. The latter are subject to entrainment of saline water into their upper water column by wind-induced mixing (Lake Romulus; Lake A in 2000), or complete flushing of their basins by dilute snowmelt (Lake C3 and Char Lake, which lies 650 km to the south of the Ellesmere lakes region). This chronosequence illustrates how changes in geomorphology and other landscape properties may influence the limnology of coastal, high-latitude lakes, and it provides a framework to explore the potential impacts of climate change. (Au)

F, G, D, A, E, J
Carbon; Chemical oceanography; Chemical properties; Climate change; Deglaciation; Electrical properties; Environmental impacts; Eutrophic lakes; Fresh-water biology; Fresh-water ecology; Geomorphology; Hydrology; Ice cover; Lake ice; Lakes; Marine ecology; Oligotrophic lakes; Phosphorus; Salinity; Sea ice; Sea level; Snowmelt; Temperature

G0813, G03
Char Lake, Nunavut; Disraeli Fiord, Nunavut; Marvin Peninsula, Nunavut; Romulus Lake, Nunavut; Taconite Inlet region, Nunavut; Taconite Inlet, Nunavut


Benthic and pelagic food resources for zooplankton in shallow high-latitude lakes and ponds   /   Rautio, M.   Vincent, W.F.
(Freshwater biology, v. 51, no. 6, June 2006, p.1038-1052, ill.)
(PCSP/PPCP contribution, no. 017-05)
References.
ASTIS record 60637.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/209.pdf
Web: doi:10.1111/j.1365-2427.2006.01550.x
Libraries: ACU

Summary: 1. Shallow lakes and ponds are a major component of the northern landscape and often contain a high zooplankton biomass despite clear waters that are poor in phytoplankton. 2. In this study we quantified zooplankton food sources and feeding rates in the shallow waters of two contrasting high-latitude biomes: subarctic forest tundra (Kuujjuarapik, Quebec) and high arctic polar desert (Resolute, Nunavut). Five substrate types were tested (beads, bacteria, picophytoplankton, filamentous plankton and microbial mats). Special attention was given to the role of benthos, a component that is usually poorly integrated into models of aquatic foodwebs. 3. Consistent with observations elsewhere in the circumpolar region, high concentrations of adult macrozooplankton occurred in all sites (up to 17 100 crustaceans/m³) while phytoplankton concentrations and primary productivity were low. The communities were composed of multiple species, including Daphnia middendorfiana, Hesperodiaptomus arcticus, Leptodiaptomus minutus, Artemiopsis stefanssoni and Branchinecta paludosa. 4. Detritus made 89-98% of the planktonic resource pool and bacteria contributed the highest biomass (up to 29 mg C/m³) of the planktonic food particles available to zooplankton. Benthic resources were dominated by microbial mats that grew in nutrient-rich conditions at the base of the ponds and which dominated overall ecosystem biomass and productivity. 5. All species were flexible in their feeding but there were large, order of magnitude differences in clearance rates among taxa. These differences likely resulted from different grazing strategies among cladocerans, copepods and fairy shrimps, and possibly also from adaptation to specific food types and size ranges that occur locally in these waters. 6. The subarctic cladocerans Ceriodaphnia quadrangula and D. middendorfiana, and the arctic fairy shrimp B. paludosa were observed to graze directly on the microbial mats and the feeding experiments confirmed their assimilation of benthic substrates. The other zooplankton species showed a more pelagic feeding mode but were capable of using microbial mat filaments, thus may be indirectly linked to benthic processes via resuspension. 7. Our study indicates that the classical aquatic food web in which phytoplankton provide the sole production base for grazers does not apply to northern shallow lakes and ponds. Instead, microbial mats increase the physical complexity of these high latitude ecosystems and likely play a role in sustaining their high zooplankton biomass. (Au)

I, H, F
Algae; Animal food; Bacteria; Benthos; Biomass; Carbon; Electrical properties; Food chain; Fresh-water biology; Fresh-water ecology; Fresh-water fauna; Fresh-water flora; Grazing; Lakes; Phytoplankton; Primary production (Biology); Temperature; Trophic levels; Tundra ponds; Water pH; Zooplankton

G0826, G0813
Kuujjuarapik region, Québec; Resolute Bay region, Nunavut


A late-Holocene record of loess deposition in ice-wedge polygons reflecting wind activity and ground moisture conditions, Bylot Island, eastern Canadian Arctic   /   Fortier, D.   Allard, M.   Pivot, F.
(Holocene, v. 16, no. 5, July 2006, p. 635-646, ill., maps)
(PCSP/PPCP contribution, no. 018-05)
References.
ASTIS record 74265.
Languages: English
Web: doi:10.1191/0959683606hl960rp
Libraries: ACU

On Bylot Island, a field of tundra polygons at the margin of a glacial outwash plain contains a well-preserved syngenetic permafrost sequence of ground ice and alternating loess and organic layers that was accumulated during the late Holocene. Periods of increased deposition of loess alternated with periods of growth of bryophytes during the last 3500 years. These shifts in soil accretion regime are interpreted in terms of significant shifts of the summer surface wind conditions and active layer moisture regime (Precipitation-Evaporation or P-E), in response to regional climatic variations and recurrent changes of atmospheric circulation. There was a high level of variability and large amplitude of the P-E regime and summer surface wind conditions on a decennial and secular timescale in general. However, according to the Greenland GISP2 bi-decennial oxygen isotopes data, there was a low variability and amplitude (by a few degrees centigrade or less) of the regional mean annual air temperature. From 2950 to 2750 cal. BP, the summer climate was warmer and had the strongest and most frequent northwesterly surface winds of the late Holocene. Shifts to a weaker northwesterly summer surface wind activity preceded the dryer episodes that occurred from 2750 to 2450 and around 1850 cal. BP. Major wetter episodes occurred from 2450 to 2350, around 2050, from 1750 to 1550, from 1350 to 1150 and from 550 to 250 cal. BP. There is no clear relationship between P-E or summer surface wind regimes and air temperatures. Shifts of late Holocene summer aeolian regime can probably be better explained by the recurrence of particular synoptic circulation types in response to changes in the position of the atmospheric eastern Canadian Polar Trough. (Au)

C, E, B, H, A, F
Active layer; Atmospheric circulation; Boreholes; Cores; Deformation; Effects of climate on permafrost; Evaporation; Glacial deposits; Glacial epoch; Ground ice; Ice sheets; Ice wedges; Isotopes; Loess; Oxygen-18; Palaeoclimatology; Patterned ground; Peat; Permafrost; Radiocarbon dating; Recent epoch; Sedimentation; Sediments (Geology); Snow; Soil profiles; Soil temperature; Temporal variations; Thermal regimes; Topography; Winds

G0813, G10
Bylot Island, Nunavut; Greenland; Navy Board Inlet region, Nunavut


Common Ravens raid arctic fox food caches   /   Careau, V.   Lecomte, N.   Giroux, J.-F.   Berteaux, D.
(Journal of ethology, v. 25, no. 1, Jan. 2007, p. 79-82)
(PCSP/PPCP contribution, no. 019-05)
References.
ASTIS record 74204.
Languages: English
Web: doi:10.1007/s10164-006-0193-7
Libraries: ACU

Cache recovery is critical for evolution of hoarding behaviour, because the energy invested in caching may be lost if consumers other than the hoarders benefit from the cached food. By raiding food caches, animals may exploit the caching habits of others, that should respond by actively defending their caches. The arctic fox (Alopex lagopus) is the main predator of lemmings and goose eggs in the Canadian High Arctic and stores much of its prey in the ground. Common ravens (Corvus corax) are not as successful as foxes in taking eggs from goose nests. This generalist avian predator regularly uses innovation and opportunism to survive in many environments. Here, we provide the first report that ravens can successfully raid food cached by foxes, and that foxes may defend their caches from ravens. (Au)

I, J
Animal behaviour; Animal ecology; Animal food; Arctic foxes; Bird nesting; Evolution (Biology); Greater Snow Geese; Lemmings; Predation; Ravens; Seasonal variations; Temporal variations; Tundra ecology

G0813
Bylot Island, Nunavut


An incidence of multi-year sediment storage on channel snowpack in the Canadian High Arctic   /   Lamoureux, S.F.   McDonald, D.M.   Cockburn, J.M.H.   Lafrenière, M.J.   Atkinson, D.M.   Treitz, P.
(Arctic, v. 59, no. 4, Dec. 2006, p. 381-390, ill., maps)
(PCSP/PPCP contribution, no. 020-05)
References.
ASTIS record 60288.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic59-4-381.pdf
Web: doi:10.14430/arctic287
Libraries: ACU

During June 2005, we identified the presence of sediment buried within multi-year channel snowpack of a small river located near Cape Bounty, Melville Island, Nunavut (74°55' N, 109°35' W). Photographic evidence indicates that the sediment was deposited during the 2003 season by the initial meltwater flowing on the snowpack, which was dammed by snow upstream of a channel constriction. The resulting pond covered a minimum area of 180 m² and contained an estimated minimum 27 Mg of sediment. Suspended sediment measurements during the 2003 season indicate that deposition on the snowpack at this location represented 49%-65% of the sediment transport prior to the ponding and emplacement of the sediment on the snow, and approximately 20% of the measured sediment flux for the entire season. Multi-year snow accumulations immediately downstream exhibited similar sediment deposition on snow, but no evidence of multi-year sediment storage was present. By contrast, a similar stream in an adjacent watershed channelized rapidly, with minimal sediment deposition on the snow, and delivered a large pulse of sediment to the downstream lake. These results provide quantitative evidence for the magnitude of sediment storage on snowpack and point to the unique role that snow plays in the fluvial geomorphology of High Arctic watersheds. (Au)

F, A, E, J
Effects of climate on snow; Environmental impacts; Erosion; Geomorphology; Hydrology; Measurement; Meteorology; Puddles; River discharges; Runoff; Sediment transport; Sedimentation; Sediments (Geology); Snow; Snow cover; Snow dams; Snow hydrology; Snowmelt; Stream erosion; Stream flow; Suspended solids; Watersheds

G0813
Bounty, Cape, region, Nunavut; Melville Island, N.W.T./Nunavut


Sex discrimination and measurement bias in Northern Fulmars "Fulmarus glacialis" from the Canadian Arctic   /   Mallory, M.L.   Forbes, M.R.
(Ardea, v. 19, no. 1, 2005, p. 25-36, ill.)
(PCSP/PPCP contribution, no. 023-05)
References.
ASTIS record 68517.
Languages: English
Web: http://nou.natuurinfo.nl/website/ardea/ardea_search3.php?key=nummer&keyin=93&k2=1

The Northern Fulmar "Fulmarus glacialis" is a seabird in which both sexes have similar plumage, but sexual dimorphism in body size is apparent. We used data from 63 Northern Fulmars collected at Cape Vera, Nunavut, Canada, to develop a discriminant function to predict sex that is based on key morphometric variables. The sex of Northern Fulmars from Cape Vera can be ascertained accurately using a combination of four body characters, and using either a site-specific or generalized discriminant function model. Some differences between variables entering in the model for Cape Vera compared to models developed elsewhere for North Atlantic Northern Fulmars may reflect local population differences in typical morphometry, notably in head and bill measures. Discriminant functions developed to identify male and female Northern Fulmars appear to be robust enough to accommodate bias introduced from measurements by different biologists. (Au)

I
Animal anatomy; Biological sampling; Classification; Fulmars; Gender differences; Identification; Measurement; Plumage; Size

G0813
Vera, Cape, Nunavut


Can local ecological knowledge contribute to wildlife management? Case studies of migratory birds   /   Gilchrist, G.   Mallory, M.   Merkel, F.
(Ecology and society : a journal of integrative science for resilience and sustainability, v. 10, no. 1, June 2005, [12] p., 1 map)
(PCSP/PPCP contribution, no. 025-05)
References.
This journal (Ecology and society) is only available online.
Responses to the article are available online.
ASTIS record 60888.
Languages: English
Web: http://www.ecologyandsociety.org/vol10/iss1/art20/

Sound management of wildlife species, particularly those that are harvested, requires extensive information on their natural history and demography. For many global wildlife populations, however, insufficient scientific information exists, and alternative data sources may need to be considered in management decisions. In some circumstances, local ecological knowledge (LEK) can serve as a useful, complementary data source, and may be particularly valuable when managing wildlife populations that occur in remote locations inhabited by indigenous peoples. Although several published papers discuss the general benefits of LEK, few attempt to examine the reliability of information generated through this approach. We review four case studies of marine birds in which we gathered LEK for each species and then compared this information to empirical data derived from independent scientific studies of the same populations. We then discuss how we attempted to integrate LEK into our own conservation and management efforts of these bird species with variable success. Although LEK proved to be a useful source of information for three of four species, we conclude that management decisions based primarily on LEK, in the absence of scientific scrutiny, should be treated with caution. (Au)

I, N, T, R
Aerial surveys; Animal distribution; Animal ecology; Animal mortality; Animal population; Bird nesting; Common Eiders; Food; Harlequins; Hunting; Inuit; Ivory Gulls; Science; Sea birds; Social surveys; Subsistence; Thick-billed Murres; Traditional knowledge; Wildlife habitat; Wildlife management

G0813, G0814, G10
Arctic Bay (Hamlet), Nunavut; Baffin Island, Nunavut; Belcher Islands waters, Nunavut; Grise Fiord (Settlement), Nunavut; Kimmirut, Nunavut; Pond Inlet (Hamlet), Nunavut; Resolute, Nunavut; Sanikiluaq, Nunavut; Upernavik, Greenland


Declines in abundance and distribution of the Ivory Gull (Pagophila eburnea) in Arctic Canada   /   Gilchrist, H.G.   Mallory, M.L.
(Biological conservation, v.121, no. 2, Jan. 2005, p. 303-309, maps)
(PCSP/PPCP contribution, no. 027-05)
References.
ASTIS record 55662.
Languages: English
Web: doi:10.1016/j.biocon.2004.04.021
Libraries: ACU

The ivory gull (Pagophila eburnea) is a seabird that inhabits Arctic oceans throughout the year, often in association with polar pack ice. It is rare (<14,000 breeding pairs globally) and remains one of the most poorly known seabird species in the world. Canada supports breeding populations of international significance, and residents of communities in the Canadian High Arctic currently observe fewer ivory gulls than they did in the 1980s. However, no population trend data existed for this species in Canada prior to this study. We initiated aerial surveys in July 2002 and 2003 of most known ivory gull colonies in Canada to assess current population levels. Forty two colonies were visited, 14 of which were new discoveries. We recorded an 80% decline in numbers of nesting ivory gulls. Several of the largest known colonies were completely extirpated and those that remained supported significantly fewer nesting birds than previously observed. Results were similar in both years despite some differences in local sea ice conditions, suggesting a numerical decline in the population and not simply annual fluctuations in colony occupation. Declines have occurred in all habitat types and across the known Canadian breeding range, suggesting that causes of the decline may be related to factors occurring during migration or on wintering grounds. We recommend that international efforts now be directed at assessing population status and trends of this species in other circumpolar countries. (Au)

I, G, D, E, J, N
Aerial surveys; Animal behaviour; Animal distribution; Animal migration; Animal mortality; Animal population; Animal reproduction; Bird nesting; Climate change; Endangered species; Environmental impacts; Extirpation; Gravel; Hunting; Ice cover; Ivory Gulls; Landfills; Marine ecology; Nunataks; Pack ice; Sea ice ecology; Trophic levels; Wildlife habitat; Wildlife management

G0813, G10
Baffin Island, Nunavut; Brodeur Peninsula, Nunavut; Devon Island, Nunavut; Ellesmere Island, Nunavut; Greenland; Seymour Island, Nunavut


Fifty years of coastal erosion and retrogressive thaw slump activity on Herschel Island, southern Beaufort Sea, Yukon Territory, Canada   /   Lantuit, H.   Pollard, W.H.
(Paraglacial geomorphology : processes and paraglacial context / Edited by D. Mercier and S. Etienne. Geomorphology, v. 95, no. 1-2, 1 Mar. 2008, p. 84-102, ill., maps)
(PCSP/PPCP contribution, no. 002-06)
References.
ASTIS record 70362.
Languages: English
Web: doi:10.1016/j.geomorph.2006.07.040
Libraries: ACU

Patterns of coastal erosion in the Arctic differ dramatically from those coasts in more temperate environments. Thick sea ice and shore-fast ice limit wave-based erosional processes to a brief open water season, however despite this, permafrost coasts containing massive ice, ice wedges and ice-bonded sediments tend to experience high rates of erosion. These high rates of erosion reflect the combined thermal-mechanical processes of thawing permafrost, melting ground ice, and wave action. Climate change in the Arctic is expected to result in increased rates of coastal erosion due to warming permafrost, increasing active layer depths and thermokarst, rising sea levels, reduction in sea ice extent and duration, and increasing storm impacts. With the most ice-rich permafrost in the Canadian Arctic, the southern Beaufort Sea coast between the Tuktoyaktuk Peninsula and the Alaskan border is subject to high rates of erosion and retrogressive thaw slump activity. Under many climate change scenarios this area is also predicted to experience the greatest warming in the Canadian Arctic. This paper presents results of a remote sensing study on the long-term patterns of coastal erosion and retrogressive thaw slump activity for Herschel Island in the northern Yukon Territory. Using orthorectified airphotos from 1952 and 1970 and an Ikonos image from 2000 corrected with control points collected by kinematic differential global positioning system and processed using softcopy photogrammetric tools, mean coastal retreat rates of 0.61 m/yr and 0.45 m/yr were calculated for the periods 1952-1970 and 1970-2000, respectively. The highest coastal retreat rates are on north-west facing shorelines which correspond to the main direction of storm-related wave attack. During the period 1970-2000 coastal retreat rates for south to south-east facing shorelines displayed a distinct increase even though these are the most sheltered orientations. However, south to south-east facing shorelines correspond to the orientations where the highest densities of retrogressive thaw slumps are observed. Differences in rates of headwall retreat of retrogressive thaw slumps and coastal erosion results in the formation of larger thermokarst scars and the development of polycyclic thaw slumps on south to south-east exposures. The number and the total area of retrogressive thaw slumps increased by 125% and 160%, respectively, between 1952 and 2000. As well, the proportion of active retrogressive thaw slumps increased dramatically. Polycyclic retrogressive thaw slumps appear to develop in a periodic fashion, related to retrogressive thaw slump stage and maximum inland extent. (Au)

C, A, E, J, D
Active layer; Aerial photography; Climate change; Coast changes; Effects of climate on permafrost; Erosion; Forecasting; Geographical positioning systems; Ground ice; Mathematical models; Melting; Ocean waves; Permafrost; Remote sensing; Sea level; Sedimentary structures; Storms; Temporal variations; Thaw flow slides; Thawing; Thermokarst

G0811, G07, G0812
Canadian Beaufort Sea; Herschel Island, Yukon; Tuktoyaktuk Peninsula, N.W.T.


Nuna aliannaittuq : beautiful land : learning about traditional place names and the land from Tuktoyaktuk elders   /   Hart, E.J.   Inuvialuit Cultural Resource Centre [Sponsor]   Inuvialuit Regional Corporation [Sponsor]   Prince of Wales Northern Heritage Centre [Sponsor]   Northern Oil and Gas Action Program (Canada) [Sponsor]   Northwest Territories. Dept. of Education, Culture and Employment [Sponsor]   ConocoPhillips Canada [Sponsor]   Imperial Oil Foundation [Sponsor]
Inuvik, N.W.T. : Inuvialuit Cultural Resource Centre, 2011.
184 p. : ill., maps ; 28 cm.
(PCSP/PPCP contribution, no. 003-06)
ISBN 978-0-9810993-2-3
Back map pocket contains 9 maps.
References.
ASTIS record 74935.
Languages: English

Preface: ... I don't want young people to forget their language and the way that their [ancestors] used to live. - Joseph Avik. It is the pleasure of the Inuvialuit Cultural Resource Centre (ICRC), the Inuvialuit Regional Corporation (IRC), and the Prince of Wales Northern Heritage Centre (PWNHC) to present this book on traditional Inuvialuktun place names. It is written for Inuvialuit, especially those of Tuktoyaktuk, to present the traditional knowledge of the elders interviewed there. We hope that it will serve as a resource for classes in local schools and that non-Inuvialuit will enjoy it as well. This book is one way to respect the wishes of elders to have information on Inuvialuit culture and language passed on to the younger generations. ... The dialect of Inuvialuktun used in this book is Siglitun, which is spoken mainly in Tuktoyaktuk, Paulatuk and Sachs Harbour. ... The spelling of most place names was based on the pronunciation of elders and was verified by language specialist Beverly Amos. Family names in this book are generally spelled the way the families spell them, rather than according to the COPE system. Some families with the same last name may spell their names differently. We sometimes provide a Siglitun translation in brackets beside an English word. Siglitun has singular, dual and plural forms. We used mostly singular or plural when providing additional words in brackets. We note the use of plural by "(pl)". ... This book is not meant as a linguistic analysis of place names. ... The translations are therefore approximate rather than full analyses of the words structure and development. We hope that the meanings of the place names presented in the book provide a body of information that local language specialists and linguistics can build on in the future. Readers should also be aware that some Siglitun words may have meanings besides those shown in a translation. For example, we used nakataq to mean 'landmark,' but the Siglit dictionary shows that it can also mean 'backsight on a gun barrel' or 'sign-post'. ... Place name research is challenging when it involves working with two languages, as well as an older form of one of those languages, and with places that elders have not been to for many decades. These conditions can lead to uncertainties about the locations of places, the translation of a name, what the name means in the context of a place, how the names should be spelled, and more. Even understanding the meaning of English words for things like geographical features or animals may be challenging when these words are used differently by Inuvialuit and non-Inuvialuit researchers. The information collected on place names was verified a number of times, but the locations of some places remain approximate, as does the meaning of some names. The locations of some places listed in archival documents were not determined. ... (Au)

V, T
Culture (Anthropology); Elders; Geographical names; History; Inuit; Inuit languages; Maps; Oral history; Social surveys; Traditional knowledge; Traditional land use and occupancy

G0812
Tuktoyaktuk region, N.W.T.; Tuktoyaktuk, N.W.T.


Changes in distribution and abundance of birds on western Victoria Island from 1992-1994 to 2004-2005   /   Raven, G.H.   Dickson, D.L.
Edmonton, Alta. : Canadian Wildlife Service, Prairie and Northern Region, 2006.
x, 60 p. : ill., maps ; 28 cm.
(Technical report series - Canadian Wildlife Service, no.465)
(PCSP/PPCP contribution, no. 006-06)
ISBN 0-662-43181-2
Appendices.
References.
ASTIS record 73760.
Languages: English
Web: http://dsp-psd.pwgsc.gc.ca/collection_2009/ec/CW69-5-456E.pdf
Libraries: ACU

Annual waterfowl breeding population surveys do not adequately cover breeding grounds for many species nesting in the Canadian arctic. Baseline surveys were conducted on western Victoria Island 1992-1994. In 2004 and 2005 we resurveyed western Victoria Island to obtain current population estimates and determine trends for bird species since the 1992-1994 surveys. We calculated visibility correction factors (VCF) for the three main species encountered during the 2004-2005 surveys using a double-count method. The VCF for King Eiders (Somateria spectabilis) was 1.435, for Canada Geese (Branta hutchinsii) was 1.617, and for Long-tailed Duck (Clangula hyemalis) was 1.833. The mean breeding population estimate for King Eiders on western Victoria Island in 2004-2005 was 33 199, which is 54% below the mean estimate from the 1992-1994 surveys. Proportional population decreases occurred throughout western Victoria Island for King Eiders except on Diamond Jenness Peninsula where estimates decreased by 92%. Long-tailed Duck densities remained low throughout western Victoria Island and population estimates were slightly below those from the 1992-1994 surveys. The mean breeding population estimate for Canada Geese on western Victoria Island was 80 092; an increase of 18% over the 1992-1994 mean estimate. Mean estimates for Canada Geese on Prince Albert Peninsula increased by 244% between the two survey periods indicating the breeding range is expanding northward. White-fronted Geese (Anser albifrons) were common in the southwest but rare on northwestern Victoria Island, and showed no change in number between survey periods. Lesser Snow Geese (Chen caerulescens caerulescens) numbers more than doubled on southwestern Victoria Island between the two survey periods. Most observations were small flocks of non-breeders. Black Brant (Branta bernicla nigricans) were very rare on western Victoria Island and numbers have continued to decrease since the surveys were last completed. Estimates of Tundra Swans (Cygnus columbianus) were low in 2004 but rebounded in 2005. A late spring occurred on western Victoria Island in 2004 and likely affected estimates. More typical spring conditions were observed in 2005. Highest densities on Tundra Swans occurred in the Kagloryuak River valley and southwestern Victoria Island. Few swans were seen north of Prince Albert Sound. Sandhill Crane (Grus canadensis) observations on northwestern Victoria Island were low in 2004 but similar to swans they rebounded in 2005 to numbers more representative of the earlier surveys. Three species of loons (Gavia spp.) were observed on western Victoria Island: Yellow-billed Loons (G. adamsii), Red-throated Loons (G. stellata), and Pacific Loons (G. pacifica). Loons were distributed throughout western Victoria Island. Population indices for northwestern Victoria Island were lower than those observed in the previous surveys but numbers were stable in southwestern Victoria Island. Three species of jaegers (Stercorarisu spp.) were observed on western Victoria Island: Pomarine Jaegers (S. pomarinus), Parasitic Jaegers (S. parasiticus), and Long-tailed Jaegers (S. longicaudus). Jaeger numbers decreased since the 1992-1994 surveys, although a rebound occurred in 2005, largely due to an increasing number of Pomarine and Long-tailed Jaegers. The population rebound of Pomarine and Long-tailed Jaegers occurred in conjunction with a rebound in Snowy Owl (Bubo scandiacus) numbers, another predator of lemmings. Other raptors observed on western Victoria Island were Rough-legged Hawks (Buteo lagopus), Peregrine Falcons (Falco peregrinus), and Short-eared Owls (Asio flammeus). Glaucous Gulls (Larus hyperboreus) were widespread throughout western Victoria Island with a distribution similar to that observed during the 1992-1994 surveys. Although numbers were low in 2004 compared to the earlier surveys, they appeared to recover in 2005. (Au)

I
Aerial surveys; Animal distribution; Animal population; Birds; Brant; Canada Geese; Ducks; Geese; Gender differences; King Eiders; Long-tailed Ducks; Long-tailed Jaegers; Raptors; Sea birds; Snowy Owls; Temporal variations; Tundra Swans; Waterfowl

G07, G0812
Victoria Island, N.W.T./Nunavut


Inorganic species distribution and microbial diversity within High Arctic cryptoendolithic habitats   /   Omelon, C.R.   Pollard, W.H.   Ferris, F.G.
(Microbial ecology, v. 54, no. 4, Nov. 2007, p. 740-752, ill., maps)
(PCSP/PPCP contribution, no. 010-06)
References.
ASTIS record 74281.
Languages: English
Web: doi:10.1007/s00248-007-9235-0
Libraries: ACU

Cryptoendolithic habitats in the Canadian high Arctic are associated with a variety of microbial community assemblages, including cyanobacteria, algae, and fungi. These habitats were analyzed for the presence of metal ions by sequential extraction and evaluated for relationships between these and the various microorganisms found at each site using multivariate statistical methods. Cyanobacteria-dominated communities exist under higher pH conditions with elevated concentrations of calcium and magnesium, whereas communities dominated by fungi and algae are characterized by lower pH conditions and higher concentrations of iron, aluminum, and silicon in the overlying surfaces. These results suggest that the activity of the dominant microorganisms controls the pH of the surrounding environment, which in turn dictates rates of weathering or the possibility for surface crust formation, both ultimately deciding the structure of microbial diversity for each cryptoendolithic habitat. (Au)

H, B, E, J
Algae; Calcium; Chemical properties; Cyanophyceae; Fungi; Geochemistry; Heterotrophic bacteria; Interstitial water; Lichens; Magnesium; Metals; Meteorology; Microbial ecology; Microorganisms; Moisture transfer; Plant distribution; Plant growth; Precipitation (Meteorology); Quartz; Sandstone; Soil pH; Surface properties; Thermal regimes; Weathering

G0813, G15
Eureka region, Nunavut; McMurdo Sound region, Antarctic regions


Environmental controls on microbial colonization of High Arctic cryptoendolithic habitats   /   Omelon, C.R.   Pollard, W.H.   Ferris, F.G.
(Polar biology, v. 30, no. 1, Jan. 2007, p. 19-29, ill., maps)
(PCSP/PPCP contribution, no. 012-06)
References.
Supplementary material for this article is available online.
ASTIS record 74183.
Languages: English
Web: doi:10.1007/s00300-006-0155-0
Libraries: ACU

Sandstone outcrops around Eureka, Ellesmere Island, Nunavut (80°N) in the Canadian high Arctic are host to abundant cryptoendolithic microbial communities. Continuous measurements over 2 years (2002-2004) of climate and environmental parameters showed that cryptoendolithic habitats experience warmer temperatures and wetter conditions than the exposed rock surface. Subsurface temperature fluctuations were moderated by the thermal capacity of the rock substrate and varied as a function of depth, aspect, and albedo. Rain, snow or snowmelt substantially increased subsurface moisture levels, which persist for significant time periods after initial precipitation events. These conditions produced a habitat amenable to colonization by cyanobacteria, fungi and algae. The dominance of one microbial community over another varied between sites, however these differences existed in habitats with similar temperature conditions. Greater diversity of microorganisms at this Arctic location compared to similar habitats in the Antarctic Dry Valleys is explained by warmer temperatures during summer months that lead to longer periods for both active (~3,700 h/year) and ideal (~2,500 h/year) calculated metabolic activities as well as abundant moisture in the form of liquid water. (Au)

H, B, E, J
Albedo; Aspect; Cyanophyceae; Fungi; Instruments; Interstitial water; Meteorology; Microbial ecology; Microorganisms; Moisture transfer; Precipitation (Meteorology); Sandstone; Seasonal variations; Solar radiation; Surface properties; Surface temperature; Thermal regimes

G0813, G15
Eureka region, Nunavut; McMurdo Sound region, Antarctic regions


Diatom assemblages and their relationships to lakewater nitrogen levels and other limnological variables from 36 lakes and ponds on Banks Island, N.W.T., Canadian Arctic   /   Lim, D.S.S.   Smol, J.P.   Douglas, M.S.V.
(Hydrobiologia, v.586, no. 1, July 2007, p. 191-211, ill., maps)
(PCSP/PPCP contribution, no. 015-06)
References.
ASTIS record 73763.
Languages: English
Web: doi:10.1007/s10750-007-0623-8
Libraries: ACU

Banks Island, in the Canadian Arctic Archipelago, has been identified as an important reference site for studies of environmental change, especially as it relates to climatic warming. The island is logistically manageable (i.e. researchers can survey the entire island in one field season) and, most importantly, spans three major ecoclimatic regions supporting a diverse and large bird and mammal population. Developing upon earlier work by the authors describing the limnology of Banks Island, this current study: (1) examines which physical and chemical limnological variables influence diatom assemblages in this relatively lush island; and (2) explores variations in the diatom assemblages by ecoclimatic zones. The relationship between diatom taxa from a 36 lake/pond surface sediment calibration set and a suite of limnological variables was explored using multivariate statistics. Dominant diatom species varied based on changing limnological characteristics, particularly between the colder, ultra-oligotrophic lakes in the more northern High Arctic regions compared to the warmer, more nitrogen-rich sites in the Low Arctic regions of Banks Island. Exploration of diatom ecoclimatic and environmental preferences revealed interesting relationships, including the development of a diatom-based transfer function that could be used to track overall trends on lakewater nitrogen concentrations, which may enable future paleolimnological studies to track shifts in nutrient levels and climatic, and other environmental changes. (Au)

F, B, E, J, H
Bottom sediments; Chemical properties; Climate change; Cores; Diatoms; Fresh-water biology; Fresh-water ecology; Ice cover; Lakes; Nitrogen; Numeric databases; Oligotrophic lakes; Palaeobotany; Palaeoecology; Palaeohydrology; Recent epoch; Salinity; Suspended solids; Tundra ponds

G0812
Banks Island, N.W.T.


Recent environmental changes on Banks Island (N.W.T., Canadian Arctic) quantified using fossil diatom assemblages   /   Lim, D.S.S.   Smol, J.P.   Douglas, M.S.V.
(Journal of paleolimnology, v. 40, no. 1, July 2008, p. 385-398, ill., map)
(PCSP/PPCP contribution, no. 016-06)
References.
ASTIS record 73764.
Languages: English
Web: doi:10.1007/s10933-007-9168-0
Libraries: ACU

Banks Island (N.W.T.) has become a focal point for climate change studies in the Canadian Arctic. However, long-term climatic and environmental data are very sparse from this large island, as they are for the entire southwestern region of the Canadian Arctic Archipelago. In this paleolimnological study, diatom species assemblage shifts documented in cores collected from a pond and a lake on Banks Island were interpreted to represent a response to climate warming commencing in the nineteenth century. We found that, although the timing and overall nature of the species changes in the two cores were consistent, the signal was muted in the deeper site likely as a result of differences in ice cover extent and duration between lakes and ponds. A high-resolution study was also conducted from a second pond, at sub-decadal resolution, that only spanned the last ~60 years. In the deeper lake site, Fragilaria construens and F. pinnata dominated the assemblages, similar to those noted in other high Arctic regions where lakes are characterized by extended ice cover. In contrast, Denticula kuetzingii dominated the shallower ponds and, in the case of the pond core representing the longer time period, this taxon increased in the post-1850 sediments, likely coincident with climate warming. In all cores, diatom assemblages became more diverse and Achnanthes species (particularly A. minutissima) increased from ~1850 to the present, similar to changes documented in other Arctic regions. Beta diversity values calculated for the diatom species changes indicated that assemblage shifts in the Banks Island cores were of similar magnitude to those recorded in other Arctic regions with high species turnover, such as Ellesmere Island. A diatom-based Total Nitrogen (TN) transfer function previously developed for Banks Island was applied to the three 210Pb dated cores as an exploratory tool for inferring past changes in nitrogen concentrations. In both the lake and pond cores, diatom-inferred TN concentrations tended to increase in the more recent sediments, as may be expected with warming; however these trends were not very distinct. (Au)

F, B, H, J, E
Bathymetry; Bottom sediments; Carbon; Chemical properties; Climate change; Cores; Diatoms; Fresh-water biology; Fresh-water ecology; Ice cover; Lakes; Nitrogen; Numeric databases; Oligotrophic lakes; Palaeobotany; Palaeoecology; Palaeohydrology; Physical properties; Plant distribution; Radioactive dating; Stratigraphy; Temporal variations; Tundra ponds

G0812
Aulavik National Park, N.W.T.


Isotopic analysis of the sources of organic carbon for zooplankton in shallow Subarctic and Arctic waters   /   Rautio, M.   Vincent, W.F.
(Ecography, v. 30, no. 1, Feb. 2007, p. 77-87, ill.)
(PCSP/PPCP contribution, no. 017-06)
References.
ASTIS record 64993.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/213.pdf
Web: doi:10.1111/j.0906-7590.2007.04462.x
Libraries: ACU

Shallow high-latitude lakes and ponds are usually characterized by an oligotrophic water column overlying a biomass-rich, highly productive benthos. Their pelagic food webs often contain abundant zooplankton but the importance of benthic organic carbon versus seston as their food sources has been little explored. Our objectives were to measure the delta 13C and delta 15N isotopic signatures of pelagic and benthic particulate organic matter (POM) in shallow water bodies in northern Canada and to determine the relative transfer of this material to zooplankton and other aquatic invertebrates. Fluorescence analysis of colored dissolved organic matter (CDOM) indicated a relatively strong terrestrial carbon influence in five subarctic waterbodies whereas the CDOM in five arctic water columns contained mostly organic carbon of autochthonous origin. The isotopic signatures of planktonic POM and cohesive benthic microbial mats were distinctly different at all study sites, while non-cohesive microbial mats often overlapped in their delta 13C signals with the planktonic POM. Zooplankton isotopic signatures indicated a potential trophic link with different fractions of planktonic POM and the non-cohesive mats whereas the cohesive mats did not appear to be used as a major carbon source. The zooplankton signals differed among species, indicating selective use of resources and niche partitioning. Most zooplankton had delta 13C values that were intermediate between the values of putative food sources and that likely reflected selective feeding on components of the pelagic or benthic POM. The results emphasize the likely importance of benthic-pelagic coupling in tundra ecosystems, including for species that are traditionally considered pelagic and previously thought to be dependent only on phytoplankton as their food source. (Au)

J, I, F, H
Algae; Animal food; Benthos; Carbon; Colored dissolved organic matter; Cyanophyceae; Food chain; Fresh-water ecology; Fresh-water fauna; Fresh-water flora; Invertebrates; Isotopes; Lakes; Measurement; Nitrogen; Particulate organic matter; Phytoplankton; Trophic levels; Tundra ponds; Zooplankton

G0813, G0826
Char Lake, Nunavut; Cornwallis Island, Nunavut; Kuujjuarapik region, Québec; Meretta Lake, Nunavut


Diatom community response to multiple scales of Holocene climate variability in a small lake on Victoria Island, NWT, Canada   /   Podritske, B.   Gajewski, K.
(Quaternary science reviews, v. 26, no. 25-28, Dec. 2007, p.3179-3196, ill., maps)
(PCSP/PPCP contribution, no. 020-06)
References.
ASTIS record 70656.
Languages: English
Web: doi:10.1016/j.quascirev.2007.06.009
Libraries: ACU

A lake sediment core spanning 9900 years, collected from a small lake on western Victoria Island, NWT, Canada, provides a high resolution record of diatom community dynamics over the Holocene. Ten radiocarbon dates and 210Pb dating provided the core chronology. Loss-on-ignition (LOI), magnetic susceptibility, biogenic silica content, and diatom concentrations provided information on changes in the sedimentary environment. LOI gradually increased over the Holocene whereas magnetic susceptibility showed an inverse trend. Biogenic silica content showed three distinct peaks spaced approximately 3000 years apart. Major shifts in diatom assemblages occurred at 8100-8000, 5800-5700, and 3800-3500 cal yr BP. There is evidence of diatom community response to centennial-scale variations such as the 'Medieval Warm Period' (~1000-700 cal yr BP), 'Little Ice Age' (~800-150 cal yr BP) and recent warming. Although recent changes in diatom community composition, productivity, and species richness are apparent they were surpassed at other periods throughout the Holocene. Variations of the taxa within the genera Staurosira, Pseudostaurosira, Fragilaria, and Staurosirella, usually combined into one genus in Arctic lake sediment studies, suggest these taxa provide useful insight into paleonvironmental questions. (Au)

B, E, H, F, J, A
Atmospheric temperature; Bioclimatology; Biological productivity; Bottom sediments; Climate change; Cores; Diatoms; Effects of climate on plants; Electrical properties; Fresh-water biology; Fresh-water ecology; Geological time; Lakes; Palaeobotany; Palaeoclimatology; Palaeoecology; Plant distribution; Primary production (Biology); Radioactive dating; Recent epoch; Sedimentation; Silica; Stratigraphy; Temporal variations; Water pH

G0813
Kuujjua River region, N.W.T.


Holocene climate and vegetation change on Victoria Island, western Canadian Arctic   /   Peros, M.C.   Gajewski, K.
(Quaternary science reviews, v. 27, no. 3-4, Feb. 2008, p. 235-249, ill., maps)
(PCSP/PPCP contribution, no. 021-06)
References.
ASTIS record 70628.
Languages: English
Web: doi:10.1016/j.quascirev.2007.09.002
Libraries: ACU

A detailed pollen record from Victoria Island provides the first quantitative Holocene climate reconstruction from the western Canadian Arctic. The pollen percentage data indicate that Arctic herbs increased over the Holocene in response to long-term cooling. The influx of locally and regionally derived pollen grains varies throughout the core and tracks several major changes observed in the biogenic silica record from Arolik Lake, Alaska, and the GISP2 ice-core, suggesting that climate change closely controlled Arctic plant productivity. Using modern analogue and transfer function techniques, we generated quantitative reconstructions of mean July temperature and total annual precipitation for the past 10 000 years, to place recent climate changes within the context of Holocene climate variability. The quantitative reconstructions indicate that July temperature cooled by 1-1.5°C during the Holocene. The pollen-based reconstructions record an increase in temperature of ~0.5°C over the last 100 years, and the pollen percentage and influx data indicate impacts of recent warming on the regional vegetation. (Au)

B, E, H, I, J, A
Adaptation (Biology); Atmospheric temperature; Bioclimatology; Biological productivity; Bottom sediments; Chironomidae; Climate change; Cores; Databases; Diatoms; Effects of climate on plants; Environmental impacts; Glacial epoch; Lakes; Mass spectrometry; Mosses; Palaeobotany; Palaeoclimatology; Palaeoecology; Palaeontology; Palynology; Plant cover; Plant distribution; Plants (Biology); Pollen; Precipitation (Meteorology); Primary production (Biology); Radioactive dating; Recent epoch; Sedimentation; Silica; Spores; Stratigraphy; Taiga ecology; Temporal variations; Tundra ecology

G0812, G0813, G06
Arolik Lake, Alaska; Banks Island, N.W.T.; Bathurst Island, Nunavut; Ellesmere Island, Nunavut; Kuujjua River region, N.W.T.; Mackenzie Delta, N.W.T.; Somerset Island, Nunavut; Victoria Island, N.W.T./Nunavut


Perfluoroalkyl contaminants in the Canadian Arctic: evidence of atmospheric transport and local contamination   /   Stock, N.L.   Furdui, V.I.   Muir, D.C.G.   Mabury, S.A.
(Environmental science & technology, v. 41, no. 10, May 15, 2007, p.3529-3536, ill., maps)
(PCSP/PPCP contribution, no. 022-06)
References.
ASTIS record 83212.
Languages: English
Web: doi:10.1021/es062709x
Libraries: ACU

Perfluorosulfonates (PFSAs) and perfluorocarboxylates (PFCAs) have been hypothesized to reach remote locations such as the Canadian Arctic either indirectly as volatile precursor chemicals that undergo atmospheric transport and subsequent degradation, or directly via oceanic and atmospheric transport of the PFSAs and PFCAs themselves. Water, sediment, and air samples were collected from three Arctic lakes (Amituk, Char, and Resolute) on Cornwallis Island, Nunavut, Canada. Samples were analyzed for PFSAs and PFCAs, precursor chemicals including the fluorotelomer alcohols (FTOHs) and polyfluorinated sulfonamides (FSAs), and precursor degradation products such as the fluorotelomer unsaturated carboxylates (FTUCAs). PFSAs and PFCAs were detected in water and sediment of all three Arctic lakes (concentrations ranged from nondetect to 69 ng/L and nondetect to 85 ng/g dry weight, respectively). FTOHs and FSAs were observed in air samples (mean concentrations ranged from 2.8 to 29 pg/m³), and confirm that volatile precursors are reaching Arctic latitudes. The observation of degradation products, including FTUCAs observed in sediment and atmospheric particles, and N-ethyl perfluorooctanesulfonamide (NEtFOSA) and perfluorooctanesulfonamide (PFOSA) in air samples, indicate that degradation of the FTOHs and FSAs is occurring in the Arctic environment. PFSAs and PFCAs were also observed on atmospheric particles (mean concentrations ranged from <0.1 to 5.9 pg/m³). In addition, results of this study also indicate that local perfluoroalkyl contamination of Resolute Lake, which is located downstream of an airport wastewater input, has occurred. (Au)

E, F, B, J
Air pollution; Airports; Atmospheric chemistry; Atmospheric circulation; Bottom sediments; Chromatography; Cores; Detection; Environmental impacts; Lakes; Mass balance; Mass spectrometry; Mathematical models; Measurement; Organofluorines; Pollution; Sewage disposal; Water pollution

G0813
Amituk Lake, Nunavut; Char Lake, Nunavut; Meretta Lake, Nunavut; Resolute Lake, Nunavut


Toward a comprehensive global emission inventory of C4-C10 perfluoroalkane sulfonic acids (PFSAs) and related precursors : focus on the life cycle of C8-based products and ongoing industrial transition   /   Wang, Z.   Boucher, J.M.   Scheringer, M.   Cousins, I.T.   Hungerbühler, K.
(Environmental science & technology, v. 51, no. 8, 2017, p.3529-3536, ill.)
(PCSP/PPCP contribution, no. 022-06)
References.
ASTIS record 83216.
Languages: English
Web: doi:10.1021/acs.est.6b06191
Libraries: ACU

Here a new global emission inventory of C4-C10 perfluoroalkanesulfonic acids (PFSAs) from the life cycle of perfluorooctanesulfonyl fluoride (POSF)-based products in 1958-2030 is presented. In particular, we substantially improve and expand the previous frameworks by incorporating missing pieces (e.g., emissions to soil through land treatment, overlooked precursors) and updating parameters (e.g., emission factors, degradation half-lives). In 1958-2015, total direct and indirect emissions of perfluorooctanesulfonic acid (PFOS) are estimated as 1228-4930 tonnes, and emissions of PFOS precursors are estimated as 1230-8738 tonnes and approximately 670 tonnes for x-perfluorooctanesulfonamides/sulfonamido ethanols (xFOSA/Es) and POSF, respectively. Most of these emissions occurred between 1958 and 2002, followed by a substantial decrease. This confirms the positive effect of the ongoing transition to phase out POSF-based products, although this transition may still require substantial time and cause substantial additional releases of PFOS (8-153 tonnes) and xFOSA/Es (4-698 tonnes) in 2016 to 2030. The modeled environmental concentrations obtained by coupling the emission inventory and a global multimedia mass-balance model generally agree well with reported field measurements, suggesting that the inventory captures the actual emissions of PFOS and xFOSA/Es for the time being despite remaining uncertainties. Our analysis of the key uncertainties and open questions of and beyond the inventory shows that, among others, degradation of side-chain fluorinated polymers in the environment and landfills can be a long-term, (potentially) substantial source of PFOS. (Au)

E, D, J, C, M, F
Air pollution; Atmospheric chemistry; Atmospheric circulation; Chemical oceanography; Chemical properties; Detection; Effects monitoring; Environmental impacts; Forecasting; Landfills; Manufacturing industries; Marine pollution; Mass balance; Mathematical models; Measurement; Organofluorines; Pollution; Snow; Soils; Surface properties; Temporal variations; United Nations Stockholm Convention on Persistent Organic Pollutants; Water pollution

G0813, G02, G11
Arctic regions; Brazil; China; Devon Ice Cap, Nunavut; North Atlantic Ocean; South Atlantic Ocean


Addition to the flora of Canada? A specimen from the Arctic Archipelago, Northwest Territories, links two allopatric species of alkali grass, Puccinellia   /   Consaul, L.L.   Gillespie, L.J.   MacInnes, K.I.
(Canadian field-naturalist, v.119, no. 4, Oct.-Dec. 2005, p. 497-506, ill., map)
(PCSP/PPCP contribution, no. 023-06)
Appendices.
References.
ASTIS record 64352.
Languages: English
Libraries: ACU

A single herbarium specimen from Banks Island in the Canadian National Herbarium, Ottawa, is closest to Puccinellia wrightii (Puccinellia sect. Pseudocolpodium). This would represent a species new to Canada and an extension of over 1100 km from the previously known range in NW Alaska and NE Russia. The morphological characteristics of this specimen are compared with all taxa in P. section Pseudocolpodium and the North American P. arctica aggregate. Principal components analysis supports placement of this specimen in P. section Pseudocolpodium near P. wrightii, where it contributes to a morphological continuum between this species and P. vahliana. The new combination Puccinellia wrightii var. flava is made and a map of the current known distribution of the species in P. section Pseudocolpodium is presented. (Au)

H
Grasses; Identification; Plant anatomy; Plant collections; Plant distribution; Plant growth; Plant taxonomy

G0812, G081, G06, G14
Alaska; Banks Island No. 1 Migratory Bird Sanctuary, N.W.T.; Canadian Arctic; Egg River region, N.W.T.; Russian Arctic


Possible use of foresight, understanding, and planning by wolves hunting muskoxen   /   Mech, L.D.
(Arctic, v. 60, no. 2, June 2007, p. 145-149, ill.)
(PCSP/PPCP contribution, no. 024-06)
References.
ASTIS record 61830.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic60-2-145.pdf
Web: doi:10.14430/arctic239
Libraries: ACU

On Ellesmere Island in 2006, arctic wolves (Canis lupus arctos) were observed making a two-pronged approach to a herd of muskoxen (Ovibos moschatus) and, on another occasion, ambushing muskoxen. Both observations seemed to provide evidence that the wolves were using foresight, understanding, and planning. Although the possible use of insight and purposiveness has been documented in captive wolves, the present report is one of the few to document the possibility that freeranging wolves use these other three mental processes. (Au)

I
Animal behaviour; Animal food; Hares; Muskoxen; Planning; Predation; Wolves

G0813
Fosheim Peninsula, Nunavut


Annual arctic wolf pack size related to arctic hare numbers   /   Mech, L.D.
(Arctic, v. 60, no. 3, Sept. 2007, p. 309-311, ill.)
(PCSP/PPCP contribution, no. 026-06)
References.
ASTIS record 62431.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic60-3-309.pdf
Web: doi:10.14430/arctic222
Libraries: ACU

During the summers of 2000 through 2006, I counted arctic wolf (Canis lupus arctos) pups and adults in a pack, arctic hares (Lepus arcticus) along a 9 km index route in the area, and muskoxen (Ovibos moschatus) in a 250 km² part of the area near Eureka (80° N, 86° W), Ellesmere Island, Nunavut, Canada. Adult wolf numbers did not correlate with muskox numbers, but they were positively related (r² = 0.89; p < 0.01) to an arctic hare index. This is the first report relating wolf numbers to non-ungulate prey. (Au)

I, J, F, E
Animal distribution; Animal ecology; Animal food; Animal population; Animal reproduction; Detection; Hares; Meteorology; Muskoxen; Predation; Snow; Tundra ecology; Wolves

G0813
Eureka region, Nunavut


Modelling geomorphic response to climate change   /   Couture, N.J.   Pollard, W.H.
(Climatic change, v. 85, no. 3-4, Dec. 2007, p. 407-431, ill., maps)
(PCSP/PPCP contribution, no. 030-06)
References.
ASTIS record 74223.
Languages: English
Web: doi:10.1007/s10584-007-9309-5
Libraries: ACU

This paper develops a three-step thaw model to assess the impact of predicted warming on an ice-rich polar desert landscape in the Canadian high Arctic. Air temperatures are established for two climate scenarios, showing mean annual increases of 4.9 and 6.5°C. This leads to a lengthening of the summer thaw season by up to 26 days and increased thaw depths of 12-70 cm, depending on the thermal properties of the soil. Subsidence of the ground surface is the primary landscape response to warming and is shown to be a function of the amount and type of ground ice in various cryostratigraphic units. In areas of pore ice and thin ice lenses with a low density of ice wedges, subsidence may be as much as 32 cm. In areas with a high density of ice wedges, subsidence will be slightly higher at 34 cm. Where massive ice is present, subsidence will be greater than 1 m. Landscape response to new climate conditions can take up to 15 years, and may be as long as 50 years in certain cases. (Au)

E, C, J
Atmospheric temperature; Climate change; Effects of climate on permafrost; Ground ice; Heat transmission; Ice wedges; Mathematical models; Permafrost; Seasonal variations; Subsidence; Temporal variations; Thawing; Thermal properties; Thickness

G0813
Ellesmere Island, Nunavut; Eureka, Nunavut; Fosheim Peninsula, Nunavut


Physical and chemical limnological characteristics of lakes and ponds across environmental gradients on Melville Island, Nunavut/N.W.T., High Arctic Canada   /   Keatley, B.E.   Douglas, M.S.V.   Smol, J.P.
(Fundamental and applied limnology = Archiv für Hydrobiologie : official journal of the International Association of Theoretical and Applied Limnology, v.168, no. 4, Apr. 2007, p. 355-376, ill., maps)
(PCSP/PPCP contribution, no. 032-06)
References.
ASTIS record 73765.
Languages: English
Web: doi:10.1127/1863-9135/2007/0168-0355
Libraries: ACU

Physical and chemical limnological variables were measured from 40 ponds and 6 lakes across Melville Island, Nunavut/N.W.T., Canadian high Arctic, an environmentally sensitive region where very limited limnological data were available. Mean values of most variables were mid-range when compared to other high Arctic limnological surveys, yet the ranges of most measured variables were amongst the largest yet encountered in Canadian high Arctic regional surveys. The first two axes of a Principal Components Analysis explained 55.2% of the variation in the environmental data. Variables most strongly associated with axis one were pH, dissolved organic carbon, total dissolved nitrogen, specific conductivity and related variables, while axis two represented gradients of other nutrients and trace metals. High elevation sites near permanent ice caps recorded the lowest specific conductivity and Ca2+ values yet reported in high Arctic systems. High phosphorus values (>20 µg/L) in some of the Melville Island sites are likely indicative of re-suspended sediments, rather than eutrophic conditions. Total nitrogen to total phosphorus ratios suggest that ~50% of the sites are P limited, while 33% are N limited, supporting previous research which suggests N limitation is more commonly encountered in Arctic than in temperate freshwater ecosystems. Finally, when freshwater sites on Melville Island were grouped according to predefined bioclimatic zones, only the most lushly vegetated zone appeared to affect limnological conditions. with these sites having higher mean total dissolved nitrogen, pH, and specific conductivity. (Au)

F, B, H, E, J
Bathymetry; Carbon; Chemical properties; Chlorophyll; Climate change; Dissolved organic carbon; Effects monitoring; Effects of climate on plants; Electrical properties; Fresh-water biology; Fresh-water ecology; Geology; Ice cover; Lakes; Measurement; Metals; Nitrogen; Palaeoclimatology; Palaeoecology; Phosphorus; Physical properties; Plant distribution; Silica; Taiga ecology; Temperature; Temporal variations; Topography; Trace elements; Tundra ponds; Water pH

G0812, G0813
Alert, Nunavut; Axel Heiberg Island, Nunavut; Banks Island, N.W.T.; Devon Island, Nunavut; Ellef Ringnes Island, Nunavut; Melville Island, N.W.T./Nunavut; Prince Patrick Island, N.W.T.; Queen Elizabeth Islands, N.W.T./Nunavut; Victoria Island, N.W.T./Nunavut


The structure and dynamics of earth hummocks in the Subarctic forest near Inuvik, Northwest Territories, Canada   /   Kokelj, S.V.   Burn, C.R.   Tarnocai, C.
(Arctic, antarctic, and alpine research, v. 39, no. 1, Feb. 2007, p. 99-109, ill., maps)
(PCSP/PPCP contribution, no. 033-06)
References.
ASTIS record 64354.
Languages: English
Web: doi:10.1657/1523-0430(2007)39[99:TSADOE]2.0.CO;2
Libraries: ACU

Surface microrelief, permafrost table configuration, ground-ice, and soil organic-matter contents are described for three sites near Inuvik, N.W.T., that are characterized by collapsed, poorly developed, and well-developed earth hummocks, respectively. The diameters of collapsed earth hummocks were significantly greater than those of well-developed vegetated hummocks. Hummock relief and inter-hummock distance increased along the continuum of forms, with the widest spacing and greatest relief measured at the site with well-developed vegetated hummocks. A bowl-shaped permafrost table mirrored the surface relief of most hummocks, but the collapsed hummocks were underlain by a planar or domed permafrost table. Segregated ice lenses parallel to the permafrost table, and small bodies of intrusive ice, were observed beneath the developing and well-developed hummocks. The configuration of the permafrost table and hummock relief, long-term observations of active-layer and hummock change, and hummock response to surface manipulation indicate that formation of a bowl-shaped permafrost table in association with organic accumulation and development of near-surface ground ice thrusts soils inward and upward causing hummock growth, whereas thaw subsidence may cause outward spreading and hummock collapse. Reaction-wood rings in black spruce trees growing on hummocky terrain indicate that tree tilting was associated with active-layer thinning and hummock growth. Cessation of reaction wood coincided with a period of active-layer deepening, degradation of ground ice, and outward spreading of the hummocks. In subarctic forests, hummock dynamics may be driven by ecological change associated with the fire cycle or climate change. (Au)

C, A, H, J
Active layer; Black spruces; Dendrochronology; Fire ecology; Formation; Fracturing; Frost action; Ground ice; Growth; Hummocks; Mosses; Movement; Permafrost; Shrubs; Size; Soil profiles; Soils; Taiga ecology; Thaw settlement; Thickness; Topography

G0812
Caribou Creek region, N.W.T.; Inuvik region, N.W.T.


Remote sensing of Arctic vegetation : relations between the NDVI, spatial resolution and vegetation cover on Boothia Peninsula, Nunavut   /   Laidler, G.J.   Treitz, P.M.   Atkinson, D.M.
(Arctic, v. 61, no. 1, Mar. 2008, p. 1-13, ill., maps)
(PCSP/PPCP contribution, no. 036-06)
References.
ASTIS record 63652.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic61-1-1.pdf
Web: doi:10.14430/arctic2
Libraries: ACU

Arctic tundra environments are thought to be particularly sensitive to changes in climate, whereby alterations in ecosystem functioning are likely to be expressed through shifts in vegetation phenology, species composition, and net ecosystem productivity (NEP). Remote sensing has shown potential as a tool to quantify and monitor biophysical variables over space and through time. This study explores the relationship between the normalized difference vegetation index (NDVI) and percent-vegetation cover in a tundra environment, where variations in soil moisture, exposed soil, and gravel till have significant influence on spectral response, and hence, on the characterization of vegetation communities. IKONOS multispectral data (4 m spatial resolution) and Landsat 7 ETM + data (30 m spatial resolution) were collected for a study area in the Lord Lindsay River watershed on Boothia Peninsula, Nunavut. In conjunction with image acquisition, percent cover data were collected for twelve 100 m × 100 m study plots to determine vegetation community composition. Strong correlations were found for NDVI values calculated with surface and satellite sensors, across the sample plots. In addition, results suggest that percent cover is highly correlated with the NDVI, thereby indicating strong potential for modeling percent cover variations over the region. These percent cover variations are closely related to moisture regime, particularly in areas of high moisture (e.g., water-tracks). These results are important given that improved mapping of Arctic vegetation and associated biophysical variables is needed to monitor environmental change. (Au)

H, A, C, J, B, E
Aerosols; Biomass; Carbon dioxide; Climate change; Effects monitoring; Environmental impacts; Geomorphology; Glacial deposits; Grasses; Gravel; Lichens; Mapping; Mathematical models; Mosses; Optical properties; Patterned ground; Periglacial landforms; Plant cover; Plant distribution; Plant-soil relationships; Plant-water relationships; Plants (Biology); Polar deserts; Remote sensing; Satellite photography; Sedges; Shrubs; Soil moisture; Surface properties; Tundra ecology; Weather stations

G0813
Boothia Peninsula, Nunavut; Bounty, Cape, Nunavut; Bounty, Cape, region, Nunavut; Lord Lindsay River region, Nunavut; Sanagak Lake region, Nunavut


Monitoring surface moisture state in the Canadian High Arctic using synthetic aperture radar (SAR)   /   Wall, J.   Collingwood, A.   Treitz, P.
(Special issue : International Polar Year / Edited by C. Derksen and P. Treitz. Canadian journal of remote sensing, v. 36, suppl. 1, Jan. 2010, p.S124-S134, ill., maps)
(PCSP/PPCP contribution, no. 038-06)
References.
ASTIS record 71855.
Languages: English
Web: http://article.pubs.nrc-cnrc.gc.ca/RPAS/rpv?hm=HInit&calyLang=eng&journal=cjrs&volume=36&afpf=m10-017.pdf
Libraries: ACU

Research was initiated in July 2004 to determine if change-detection methods employing synthetic aperture radar (SAR) could be applied to estimate change in soil moisture over a growing season for a site in the Canadian High Arctic. Two change-detection methods, image ratioing and principal component analysis (PCA), were assessed for their potential to provide accurate soil moisture change information. Volumetric moisture estimates from bulk soil samples were collected at 36 test sites concomitant with two descending RADARSAT-1 C-HH standard beam images collected on 8 July and 1 August 2004. Regression analyses between soil moisture values and image backscatter were performed for the 8 July and 1 August backscatter images (r² = 0.099 and 0.413, respectively). The correlation between soil moisture change and image ratio values was poor (r² = 0.038). A similar regression was performed between the soil moisture change values and the first and second principal component image values (r² = 0.003 and 0.131, respectively). Weak correlations were largely attributed to saturated ground conditions during the 8 July image acquisition which are believed to have caused a specular reflection mechanism and reduced overall image backscatter. The higher correlation between late season soil moisture and SAR backscatter (1 August, r² = 0.413) reinforces the suggestion that extremely wet and saturated ground conditions during early season lead to adverse results when assuming a linear relationship between moisture values and image backscatter. Lastly, despite the low correlation coefficients, the ratio and second principal component images displayed spatial similarities with respect to drainage networks and snowbank melt areas, suggesting the utility of these techniques for delineating moisture-saturated areas between dates. (Au)

A, C, F
Cores; Detection; Drainage; Growing season; Mathematical models; Measurement; Melting; Quality assurance; Radar; Remote sensing; SAR; Satellites; Snowpatches; Soil moisture; Soils; Surface properties; Temporal variations

G0813
Bounty, Cape, region, Nunavut


Ross's Gull (Rhodostethia rosea) breeding in Penny Strait, Nunavut, Canada   /   Mallory, M.L.   Gilchrist, H.G.   Mallory, C.L.
(Arctic, v. 59, no. 3, Sept. 2006, p. 319-321, 1 map)
(PCSP/PPCP contribution, no. 042-06)
References.
ASTIS record 59693.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic59-3-319.pdf
Web: doi:10.14430/arctic317
Libraries: ACU

We found a small, previously undiscovered breeding colony of Ross's gulls (Rhodostethia rosea) in Nunavut, Canada, approximately 80 km from a previous colony location occupied during the 1970s. The birds nested in association with arctic terns (Sterna paradisaea). The collective observations from this region of the High Arctic suggest that Ross's gulls may move colonies each year, or that colony occupation is intermittent. (Au)

I, G, A, T
Animal behaviour; Animal distribution; Arctic foxes; Arctic Terns; Bird nesting; Ice cover; Inuit; Islands; Predation; Ross' Gulls; Sea ice; Traditional knowledge; Wildlife habitat

G0813, G0815, G14
Baffin Island, Nunavut; Penny Strait region, Nunavut; Penny Strait, Nunavut; Prince Charles Island, Nunavut; Sibir', Russian Federation


Elevated mercury levels in a declining population of Ivory Gulls in the Canadian Arctic   /   Braune, B.M.   Mallory, M.L.   Gilchrist, H.G.
(Marine pollution bulletin, v. 52, no. 8, Aug. 2006, p. 978-982, ill., maps)
(PCSP/PPCP contribution, no. 043-06)
References.
ASTIS record 59746.
Languages: English
Web: doi:10.1016/j.marpolbul.2006.04.013
Libraries: ACU

The ivory gull (Pagophila eburnea) is a high Arctic marine bird which is in serious population decline for reasons unknown. Local ecological knowledge interviews and colony surveys indicate an 80% decline in numbers of nesting ivory gulls in Arctic Canada since the early 1980s .... Ivory gulls feed largely on fish and invertebrates, but also scavenge placentae, faeces and carrion of marine mammals .... Given their relatively high trophic position in marine food webs ..., contaminants have been proposed as one stressor which could be affecting this species. ... (Au)

I, J, D
Animal distribution; Animal food; Animal mortality; Animal population; Biological sampling; Biomagnification; Bird nesting; Fishes; Food chain; Fulmars; Glaucous Gulls; Invertebrates; Ivory Gulls; Kittiwakes; Marine pollution; Mercury; Metabolism; Thick-billed Murres; Toxicity; Water masses

G0813, G09, G0815
Baffin Bay-Davis Strait; Canadian Arctic Islands waters; Coats Island, Nunavut; Devon Island, Nunavut; Prince Leopold Island, Nunavut; Seymour Island, Nunavut; Southampton Island, Nunavut


Status, trends and attendance patterns of the Northern Fulmar, Fulmaris glacialis, in Nunavut, Canada   /   Gaston, A.J.   Mallory, M.L.   Gilchrist, H.G.   O'Donovan, K.
(Arctic, v. 59, no. 2, June 2006, p. 165-178, ill., maps)
(PCSP/PPCP contribution, no. 044-06)
References.
ASTIS record 59238.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic59-2-165.pdf
Web: doi:10.14430/arctic339
Libraries: ACU

Nunavut supports ten breeding colonies of northern fulmars (Fulmarus glacialis), most of which have rarely been visited on the ground by biologists. During 2000-04, we surveyed six colonies previously thought to support more than 80% of the Canadian Arctic population, which was believed to number about 300 000 breeding pairs. Our counts suggested that the breeding populations of some colonies, especially those at the largest colonies, Cape Searle and Prince Leopold Island, were substantially smaller than previously estimated. Our estimate for the total population of Nunavut was approximately 200 000 occupied sites. However, counts made at fixed monitoring plots at Prince Leopold Island and total colony estimates at Cape Vera, Devon Island, suggested no change in numbers at those colonies since the 1970s. Numbers present at the colony peaked in late June-early July and fell sharply after the end of July. Cyclical attendance, identified in an earlier study, was irregular in period length and was not seen in all years. We concluded that counts of Apparently Occupied Sites (AOS) conducted daily for 10-15 days are the best monitoring protocol for northern fulmars at these Arctic colonies. The great day-to-day variability in counts may have contributed to the large differences between past and recent population estimates. (Au)

I, J, E
Animal distribution; Animal population; Animal reproduction; Bird nesting; Climate change; Fulmars; Geographical positioning systems; Logistics; Measurement; Photography; Temporal variations; Wildlife habitat

G0813
Akpat Bay region, Nunavut; Baillarge Bay region, Nunavut; Buchan Gulf region, Nunavut; Exeter Island, Nunavut; Hobhouse Inlet region, Nunavut; Liddon, Cape, Nunavut; Prince Leopold Island, Nunavut; Princess Charlotte Monument, Nunavut; Scott Inlet region, Nunavut; Searle, Cape, Nunavut; Vera, Cape, Nunavut


Contaminant concentrations in breeding and non-breeding Northern Fulmars (Fulmarus glacialis L.) from the Canadian High Arctic   /   Mallory, M.L.   Braune, B.M.   Forbes, M.R.L.
(Persistent organic pollutants and dioxins / Edited by L.L. Needham and H. Fiedler. Chemosphere (Oxford), v. 64, no. 9, Aug. 2006, p.1541-1544)
(PCSP/PPCP contribution, no. 045-06)
References.
ASTIS record 59510.
Languages: English
Web: doi:10.1016/j.chemosphere.2005.11.058
Libraries: ACU

Persistent organic pollutants (POPs) were measured in livers of male and female northern fulmars (Fulmarus glacialis) shortly after egg-laying on northern Devon Island, NU, Canada. Breeding females had lower hepatic POPs (lipid normalised) than breeding males, but non-breeding males and females had similar concentrations. We suspect that breeding females are eliminating some of their POPs during egg formation. Concentrations of measured POPs were lower than those associated with avian health concerns, and there was no evidence that POPs in the birds were contributing to additional breeding stress. (Au)

J, I
Age; Animal health; Animal physiology; Animal reproduction; Biological sampling; Bird nesting; Blood; Chlordanes; Chromatography; DDT; Dieldrin; Fulmars; Gender differences; HCB; HCH; Internal organs; Lipids; Logistics; Mass spectrometry; Measurement; Mirex; Necropsy; Organochlorines; PCBs; Pollution; POPs; Toxicity

G0813
Vera, Cape, Nunavut


Proglacial succession of biological soil crusts and vascular plants : biotic interactions in the High Arctic   /   Breen, K.   Lévesque, E.
(Canadian journal of botany, v. 84, no. 11, Nov. 2006, p.1714-1731, ill., maps)
(PCSP/PPCP contribution, no. 001-07)
Appendix.
References.
ASTIS record 74027.
Languages: English
Web: doi:10.1139/B06-131
Libraries: ACU

To evaluate the hypothesis that biological soil crusts facilitate the establishment and maintenance of vascular plants during succession, we studied the distribution patterns of crusts and vascular plants along a High Arctic glacier foreland and compared the success of plants growing in and out of crusted substrate. Multivariate analyses determined that distance from the glacier and crust cover were the most important variables, explaining 11% and 9% of the variance in the vegetation data, respectively. Surfaces colonized by biological soil crusts generally supported higher plant densities and showed positive associations with the most dominant, long-lived plant species such as Saxifraga oppositifolia L., Salix arctica Pall., and Dryas integrifolia Vahl. Crusts facilitate plant establishment and growth in early and midsuccession but may compete for available resources further along the chronosequence. This study recognizes subtle direct influences of crust on vegetation density but also draws attention to a much larger overall positive effect on community structure. Succession on this foreland proceeds via a "directional-replacement" model and supports a well-developed community of biological soil crusts and vascular plants with greater species richness, cover, and density compared with other glacier foreland vegetation communities previously investigated on Ellesmere Island, Nunavut. (Au)

C, H, I, F, A
Carbon; Cores; Deglaciation; Dryas; Glacial deposits; Glacial melt waters; Glaciers; Identification; Lichens; Mosses; Nitrogen; Phosphorus; Plant cover; Plant distribution; Plant growth; Plant nutrition; Plant succession; Plant-soil relationships; Plants (Biology); Potassium; Runoff; Saxifraga; Soil microorganisms; Soil moisture; Soil pH; Soil texture; Soils; Spatial distribution; Stellaria; Willows

G0813
Sverdrup Pass, Nunavut; Teardrop Glacier, Nunavut


Feeding ecology of Greater Snow Goose goslings in mesic tundra on Bylot Island, Nunavut, Canada   /   Audet, B.   Gauthier, G.   Lévesque, E.
(The Condor (Los Angeles, Calif.), v.109, no. 2, May 2007, p. 361-376, ill.)
(PCSP/PPCP contribution, no. 008-07)
References.
Spanish abstract provided.
ASTIS record 74200.
Languages: English
Web: doi:10.1650/0010-5422(2007)109[361:FEOGSG]2.0.CO;2
Libraries: ACU

Although mesic tundra is a habitat commonly used by arctic-nesting geese, their feeding ecology in this habitat is little known compared to wetlands. Our objectives were to determine the diet and food selection of Greater Snow Goose (Chen caerulescens atlantica) goslings in relation to the nutritional quality of plants growing in mesic tundra habitats on Bylot Island, Nunavut, Canada. We used two different but complementary approaches: examination of esophageal contents of sacrificed wild goslings, and direct observation of the feeding activity of captive, human-imprinted goslings. The latter method was innovative and provided a reliable description of the diet, with results comparable to those obtained from wild goslings. Although mesic habitats have a more diverse floristic composition than wetlands and sparse graminoid cover, Gramineae were preferentially selected and dominated the diet (~50%). The rest of the diet consisted mainly of members of the Juncaceae, Polygonaceae, and Leguminosae families. The diet of very young goslings was diverse, but as they aged and gained efficiency, they concentrated on a few taxa. Goslings ate mostly leaves (~80%), but flowers (~20%) were also important. Food selection was influenced by nitrogen and total phenolic compounds content of plants, but the ratio of phenolic compounds to nitrogen in plant organs was most determinative of food choice. Neutral detergent fiber content of plants did not influence plant selection. Both plant nutritional quality and availability determined gosling diet across different mesic habitats and growing goslings appeared to maximize their intake of metabolizable proteins. (Au)

I, J, J
Age; Animal behaviour; Animal ecology; Animal food; Animal live-capture; Bird nesting; Flowers; Grasses; Greater Snow Geese; Intestines; Leaves; Necropsy; Nitrogen; Plants (Biology); Tundra ecology

G0813
Bylot Island, Nunavut


Free love in the Far North : plural breeding and polyandry of arctic foxes (Alopex lagopus) on Bylot Island, Nunavut   /   Carmichael, L.E.   Szor, G.   Berteaux, D.   Giroux, M.A.   Cameron, C.   Strobeck, C.
(Canadian journal of zoology, v. 85, no. 3, Mar. 2007, p. 338-343, maps)
(PCSP/PPCP contribution, no. 009-07)
References.
Supplemental material available online.
ASTIS record 74028.
Languages: English
Web: doi:10.1139/Z07-014
Libraries: ACU

Molecular studies show that canid breeding systems are more complex than field data have sometimes suggested. For example, microsatellite DNA fingerprints of offspring and adults within their social group indicate that many canid species thought to form monogamous pairs engage in polygyny, polyandry, and plural breeding. In many areas, arctic foxes (Alopex lagopus (L., 1758)) are considered monogamous, with the complexity of their social systems increasing as population isolation increases. We combined a genetic approach with spatial data of arctic foxes on Bylot Island, Nunavut, Canada, to investigate breeding patterns in a population less isolated than many previously studied. As in previous field studies, single breeding pairs were most common, but one case of plural breeding and one case of polyandry with multiple paternity were also observed. Reproductive output in arctic foxes is closely tied to the productivity of their habitat in a given year; we support the hypothesis that abundant resources at our study site have also contributed to complex breeding patterns among resident foxes. We also suggest that increased genetic variation among offspring of multiply mated females may provide an additional adaptive advantage to species in uncertain environments. (Au)

I
Animal behaviour; Animal live-capture; Animal reproduction; Animal tagging; Arctic foxes; Biological sampling; Denning; Genetics; Geographical positioning systems; Pelage; Size

G0813
Bylot Island, Nunavut


Holocene climate inferred from biological (Diptera: Cironomidae) analyses in a Southampton Island (Nunavut, Canada) lake   /   Rolland, N.   Larocque, I.   Francus, P.   Pienitz, R.   Laperrière, L.
(Holocene, v. 18, no. 2, Feb. 2008, p. 229-241, ill., maps)
(PCSP/PPCP contribution, no. 011-07)
References.
ASTIS record 74277.
Languages: English
Web: doi:10.1177/0959683607086761
Libraries: ACU

Concerns about the effects of global warming on Arctic environments have stimulated multidisciplinary research into the history of their long-term climatic and environmental variability to improve future predictions of climate in these remote areas. Here we present the first palaeolimnological study for Southampton Island using analyses of chironomids supported by sedimentological analyses, carried out on a 1 m long core retrieved from a lake located in the northeastern part of the island. This core was made up of marine sediments underneath 65 cm of freshwater lake sediments. A marine shell, humic-acids and chironomid head capsules were used to date this sequence. The Holocene environmental history of the lake consisted of two major contrasting periods. The first one, between about 5570 and 4360 cal. yr BP, was climatically unstable, with common postglacial chironomid taxa such as Corynocera oliveri-type, Paracladius and Microspectra radialis-type. This period also corresponded to the highest chironomid-inferred August air temperature (10°C) for the whole record and to significant increases in major chemical elements as detected by x-ray fluorescence. During the second period, which lasted from about 3570 cal. yr BP until the present, limnological conditions seemed to stabilize after a change to cold oligotrophic chironomid taxa, such as Heterotrissocladius subpilosus-group, with no major variations in the abundance of chemical elements. Inferred August air temperatures ranged between 8 and 9°C. This study provided unique information on the timing of the Holocene Thermal Maximum in the Foxe Basin area, a region with very little information available on long-term climate change. This region showed, so far, relatively few signs of recent climatic change, as opposed to other regions in the High Arctic. (Au)

B, E, I, A
Animal distribution; Animal taxonomy; Biological productivity; Bottom sediments; Carbon; Chironomidae; Climate change; Cores; Deglaciation; Fresh-water biology; Fresh-water ecology; Geochemistry; Lakes; Midges; Nitrogen; Palaeoclimatology; Palaeoecology; Palaeohydrology; Palaeontology; Radiocarbon dating; Recent epoch; Sedimentation

G0813
Southampton Island, Nunavut


Limnological characteristics of a High Arctic oasis and comparisons across northern Ellesmere Island   /   Keatley, B.E.   Douglas, M.S.V.   Smol, J.P.
(Arctic, v. 60, no. 3, Sept. 2007, p. 294-308, ill., maps)
(PCSP/PPCP contribution, no. 012-07)
References.
ASTIS record 62429.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic60-3-294.pdf
Web: doi:10.14430/arctic221
Libraries: ACU

Rapidly warming temperatures in the Arctic are predicted to markedly alter the limnology of tundra lakes and ponds. These changes include increases in aquatic production, pH, specific conductivity, and nutrient levels. However, baseline limnological data from High Arctic regions are typically restricted to single sampling events or to repeated samplings of a few select sites, which limits our ability to assess the influence of climatic change. We employ two techniques to examine the influence of a warmer climate on High Arctic aquatic ecosystems. First, we compare limnological characteristics in July 2003 of 23 ponds and lakes from an atypically warm High Arctic oasis on Ellesmere Island to those of 32 ponds and lakes located across northern Ellesmere Island, where climatic conditions are much cooler and more typical of High Arctic environments. Second, we resample 13 sites originally analyzed in 1963 to assess the influence that 40 years of rising temperatures (as documented by meteorological records) have had on the limnological characteristics of these freshwater ecosystems. The specific conductivity values, as well as the concentrations of nutrients and related variables (especially dissolved organic carbon, DOC), from the Arctic oasis sites are among the highest yet reported from the Canadian High Arctic, and they are significantly higher than those from the polar desert around northern Ellesmere Island. Comparison of the modern and historical data indicated that most oasis sites currently have higher pH than they did in 1963, which is consistent with the documented warming of temperatures. (Au)

F, E, J
Biological productivity; Calcium; Carbon cycling; Chemical properties; Climate change; Climatology; Dissolved organic carbon; Electrical properties; Environmental impacts; Fresh-water biology; Fresh-water ecology; Heavy metals; Magnesium; Meteorology; Nitrogen; Numeric databases; Phosphorus; Physical properties; Polar deserts; Potassium; Precipitation (Meteorology); Salt; Sulphates; Temperature; Temporal variations; Tundra ponds; Water pH

G0813
Ellesmere Island, Nunavut; Hazen, Lake, region, Nunavut; Quttinirpaaq National Park, Nunavut


Seasonal variation in plant nutritive quality for Greater Snow Goose goslings in mesic tundra   /   Audet, B.   Lévesque, E.   Gauthier, G.
(Canadian journal of botany, v. 85, no. 5, May 2007, p. 457-462, ill.)
(PCSP/PPCP contribution, no. 013-07)
References.
French abstract provided.
ASTIS record 74202.
Languages: English
Web: doi:10.1139/B07-039
Libraries: ACU

Variation in nutritive quality over time and among forage plants is important for herbivores such as geese. We examined the seasonal variation of some nutritive attributes (nitrogen, neutral detergent fibre, and phenolic compounds) of five plant species consumed by Greater Snow Geese (Chen caerulescens atlantica) L. in mesic tundra, a habitat where goose feeding ecology has been little studied compared with wetlands. We sampled ungrazed, aboveground plant tissues five times at 10-14 d intervals between 1 July and 15 August 2003 on Bylot Island, Nunavut. The species were Arctagrostis latifolia (R. Br.) Griseb. (Gramineae), Luzula nivalis (Laest.) Beurl. (Juncaceae), Oxytropis maydelliana Trautv. (Legu-minosae), Oxyria digyna (L.) Hill, and Polygonum viviparum L. (both Polygonaceae). All species showed a seasonal decline in nitrogen content in both leaves and flowering heads (includes flowers and fruits) but the amplitude was variable among species (from 10% to 62% decline depending on the species). Neutral detergent fibre concentration in leaves remained stable or increased slightly over time in contrast to flowering heads where it increased in all species (from 7% to 94%). Fibre content was higher in flowering heads than in leaves. The total content of phenolic compounds varied throughout the summer. In some cases, the content of phenolic compounds remained stable but in others it initially increased and then decreased later on, or it increased throughout the summer. Seasonal variations in plant nutritive quality were smaller than interspecific differences. The nitrogen content of forbs (especially Oxytropis) was high and their fibre content low compared with the grass and rush species (Luzula), particularly during the early summer. (Au)

I, J, J
Age; Animal behaviour; Animal ecology; Animal food; Animal live-capture; Bird nesting; Flowers; Grasses; Greater Snow Geese; Intestines; Leaves; Necropsy; Nitrogen; Plants (Biology); Seasonal variations; Tundra ecology

G0813
Bylot Island, Nunavut


Historical and ecological determinants of genetic structure in Arctic canids   /   Carmichael, L.E.   Krizan, J.   Nagy, J.A.   Fuglei, E.   Dumond, M.   Johnson, D.   Veitch, A.   Berteaux, D.   Strobeck, C.
(Molecular ecology, v. 16, no. 16, Aug. 2007, p.3466-3483, ill., maps)
(PCSP/PPCP contribution, no. 015-07)
References.
ASTIS record 74030.
Languages: English
Web: doi:10.1111/j.1365-294X.2007.03381.x
Libraries: ACU

Wolves (Canis lupus) and arctic foxes (Alopex lagopus) are the only canid species found throughout the mainland tundra and arctic islands of North America. Contrasting evolutionary histories, and the contemporary ecology of each species, have combined to produce their divergent population genetic characteristics. Arctic foxes are more variable than wolves, and both island and mainland fox populations possess similarly high microsatellite variation. These differences result from larger effective population sizes in arctic foxes, and the fact that, unlike wolves, foxes were not isolated in discrete refugia during the Pleistocene. Despite the large physical distances and distinct ecotypes represented, a single, panmictic population of arctic foxes was found which spans the Svalbard Archipelago and the North American range of the species. This pattern likely reflects both the absence of historical population bottlenecks and current, high levels of gene flow following frequent long-distance foraging movements. In contrast, genetic structure in wolves correlates strongly to transitions in habitat type, and is probably determined by natal habitat-biased dispersal. Nonrandom dispersal may be cued by relative levels of vegetation cover between tundra and forest habitats, but especially by wolf prey specialization on ungulate species of familiar type and behaviour (sedentary or migratory). Results presented here suggest that, through its influence on sea ice, vegetation, prey dynamics and distribution, continued arctic climate change may have effects as dramatic as those of the Pleistocene on the genetic structure of arctic canid species. (Au)

I, J, E, F, A
Animal behaviour; Animal distribution; Animal ecology; Animal food; Animal migration; Arctic foxes; Biological sampling; Blood; Caribou; Climate change; Environmental impacts; Genetics; Geographic information systems; Glacial epoch; Movement; Pelage; Pleistocene epoch; Predation; Refugia; Tundra ecology; Ungulates; Wildlife habitat; Wolves

G081, G08, G06, G13
Alaska; Canada; Canadian Arctic; Svalbard


Hydroclimate controls over seasonal sediment yield in two adjacent High Arctic watersheds   /   Cockburn, J.M.H.   Lamoureux, S.F.
(Hydrological processes, v. 22, no. 12, 15 June 2008, p.2013-2027, ill., maps)
(PCSP/PPCP contribution, no. 016-07)
References.
The PCSP/PPCP contribution number is incorrectly given as 016-17 in the Acknowledgments of this article. The correct number is 016-07.
ASTIS record 65621.
Languages: English
Web: doi:10.1002/hyp.6798
Libraries: ACU

Interannual variations in seasonal sediment transfer in two High Arctic non-glacial watersheds were evaluated through three summers of field observations (2003-2005). Total seasonal discharge, controlled by initial watershed snow water equivalence (SWE) was the most important factor in total seasonal suspended sediment transfer. Secondary factors included melt energy, snow distribution and sediment supply. The largest pre-melt SWE of the three years studied (2004) generated the largest seasonal runoff and disproportionately greater suspended sediment yield than the other years. In contrast, 2003 and 2005 had similar SWE and total runoff, but reduced runoff intensity resulted in lower suspended sediment concentrations and lower total suspended sediment yield in 2005. Lower air temperatures at the beginning of the snowmelt period in 2003 prolonged the melt period and increased meltwater storage within the snowpack. Subsequently, peak discharge and instantaneous suspended sediment concentrations were more intense than in the otherwise warmer 2005 season. The results for this study will aid in model development for sediment yield estimation from cold regions and will contribute to the interpretation of paleoenvironmental records obtained from sedimentary deposits in lakes. (Au)

F, B, E
Atmospheric temperature; Bottom sediments; Climate change; Diurnal variations; Hydrology; Lake ice; Lakes; Meteorology; River discharges; Rivers; Runoff; Seasonal variations; Sedimentation; Snow; Snow hydrology; Snow surveys; Snow water equivalent; Snowmelt; Springs (Hydrology); Stream flow; Suspended solids; Temperature; Temporal variations; Watersheds

G0813
Bounty, Cape, region, Nunavut; Mould Bay (Weather Station), N.W.T.; Rea Point (Weather Station), Nunavut


Breeding dispersal in a heterogeneous landscape : the influence of habitat and nesting success in Greater Snow Geese   /   Lecomte, N.   Gauthier, G.   Giroux, J.-F.
(Oecologia, v.155, no. 1, Feb. 2008, p. 33-41, ill.)
(PCSP/PPCP contribution, no. 017-07)
References.
ASTIS record 74029.
Languages: English
Web: doi:10.1007/s00442-007-0860-6
Libraries: ACU

Despite numerous studies on breeding dispersal, it is still unclear how habitat heterogeneity and previous nesting success interact to determine nest-site fidelity at various spatial scales. In this context, we investigated factors affecting breeding dispersal in greater snow geese (Anser caerulescens atlanticus), an Arctic breeding species nesting in two contrasting habitats (wetlands and mesic tundra) with variable pattern of snowmelt at the time of settlement in spring. From 1994 to 2005, we monitored the nesting success and breeding dispersal of individually marked females. We found that snow geese showed a moderate amount of nest-site fidelity and considerable individual variability in dispersal distance over consecutive nesting attempts. This variability can be partly accounted for by the annual timing of snowmelt. Despite this environmental constraint, habitat differences at the colony level consistently affected nesting success and settlement patterns. Females nesting in wetlands had higher nesting success than those nesting in mesic tundra. Moreover, geese responded adaptively to spatial heterogeneity by showing fidelity to their nesting habitat, independently of snowmelt pattern. From year to year, geese were more likely to move from mesic to high-quality wetland habitat, regardless of previous nesting success and without cost on their subsequent nesting performance. The unpredictability of snowmelt and the low cost of changing site apparently favour breeding-site dispersal although habitat quality promotes fidelity at the scale of habitat patches. (Au)

I, F, J
Aerial photography; Animal behaviour; Animal distribution; Animal ecology; Animal live-capture; Animal reproduction; Animal tagging; Bird nesting; Geographic information systems; Geographical positioning systems; Greater Snow Geese; Mapping; Movement; Snow cover; Snowmelt; Tundra ecology; Wetlands; Wildlife habitat

G0813
Bylot Island, Nunavut


Cessation of ice-wedge development during the 20th century in spruce forests of eastern Mackenzie Delta, Northwest Territories, Canada   /   Kokelj, S.V.   Pisaric, M.F.J.   Burn, C.R.
(Canadian journal of earth sciences, v. 44, no. 11, Nov. 2007, p.1503-1515, ill., maps)
(PCSP/PPCP contribution, no. 018-07)
References.
ASTIS record 64307.
Languages: English
Web: doi:10.1139/E07-035
Libraries: ACU

Ice wedges are presently inactive in white spruce (Picea glauca) forests of eastern Mackenzie Delta as shown by the absence of vein ice above ice wedges, the maintenance of intact breaking cables, and the abundance of rootlets propagating across ridge-trough sequences. At spruce forest sites, near-surface ground cooling rates and minimum near-surface temperatures from the years 2003-2005 were above ice-wedge cracking thresholds. Ground thermal conditions associated with cracking were recorded at a tundra peatland with active ice wedges. Annual mean permafrost temperatures at the spruce forest sites ranged from -1.8 to -2.9 °C, whereas at the tundra peatland, the permafrost was colder than -6 °C. Although winter air temperatures are similar throughout the study region, deeper snow cover, thicker active layers, and warmer permafrost account for the more gradual seasonal cooling and warmer near-surface temperatures recorded at the subarctic forest sites. The subtle ridge to trough relief, 12-35 cm of permafrost above wedge ice, roots up to 80 years old grown across ice wedges, and negligible tritium levels in wedge ice indicate that thermal contraction cracking in the spruce forests has been infrequent throughout much of the last century. The proximity of wedge ice to the base of the aggrading permafrost table and the absence of old spruce roots spanning ice-wedge troughs suggest that ice-wedge cracking did occur in the forest environments during the cold and dry conditions associated with the Little Ice Age and early part of the 20th century. When these ice wedges cracked, minimum temperatures at the top of permafrost were probably at least 3-8 °C colder than presently observed and similar to present conditions at the tundra peatland. (Au)

C, H, F, E
Active layer; Atmospheric temperature; Black spruces; Climate change; Cores; Formation; Fracturing; Ground ice; Growth; Lichens; Mosses; Peat; Plant succession; Roots; Shrubs; Snow; Soil profiles; Soil temperature; Temporal variations; Thermal properties; Thermal regimes; Thickness; Topography; Tritium; White spruces

G0812
Campbell Lake (68 12 N, 133 28 W) region, N.W.T.; Garry Island, N.W.T.; Illisarvik Lake, N.W.T.; Inuvik region, N.W.T.; Mackenzie Delta, N.W.T.; Reindeer Station region, N.W.T.


Cache and carry : hoarding behaviour of arctic fox   /   Careau, V.   Giroux, J.-F.   Berteaux, D.
(Behavioral ecology and sociobiology, v. 62, no. 1, Nov. 2007, p. 87-96, ill.)
(PCSP/PPCP contribution, no. 021-07)
References.
ASTIS record 74227.
Languages: English
Web: http://chairedb.uqar.qc.ca/documents/2007Careauetal.BES.pdf
Web: doi:10.1007/s00265-007-0441-z
Libraries: ACU

Food-hoarding animals are expected to preferentially cache items with lower perishability and/or higher consumption time. We observed arctic foxes (Alopex lagopus) foraging in a greater snow goose (Anser caerulescens atlanticus) colony where the main prey of foxes consisted of goose eggs, goslings, and lemmings (Lemmus and Dicrostonyx spp.). We recorded the number of prey consumed and cached and the time that foxes invested in these activities. Foxes took more time to consume a goose egg than a lemming or gosling but cached a greater proportion of eggs than the other prey type. This may be caused by the eggshell, which presumably decreases the perishability and/or pilfering risk of cached eggs, but also increases egg consumption time. Arctic foxes usually recached goose eggs but rarely recached goslings or lemmings. We tested whether the rapid-sequestering hypothesis could explain this recaching behavior. According to this hypothesis, arctic foxes may adopt a two-stage strategy allowing both to maximize egg acquisition rate in an undefended nest and subsequently secure eggs in potentially safer sites. Foxes spent more time carrying an egg and traveled greater distances when establishing a secondary than a primary cache. To gain further information on the location and subsequent fate of cached eggs, we used dummy eggs containing radio transmitters. Lifespan of primary caches increased with distance from the goose nest. Secondary caches were generally located farther from the nest and had a longer lifespan than primary caches. Behavioral observations and the radio-tagged egg technique both gave results supporting the rapid-sequestering hypothesis. (Au)

I, J
Animal behaviour; Animal food; Animal tagging; Arctic foxes; Bird nesting; Denning; Food preservation; Greater Snow Geese; Lemmings; Predation; Radio tracking of animals; Spatial distribution; Temporal variations

G0813
Bylot Island, Nunavut


The influence of biological soil crusts on soil characteristics along a High Arctic glacier foreland, Nunavut, Canada   /   Breen, K.   Lévesque, E.
(Arctic, antarctic, and alpine research, v. 40, no. 2, May 2008, p. 287-297, ill., map)
(PCSP/PPCP contribution, no. 022-07)
References.
ASTIS record 74031.
Languages: English
Web: doi:10.1657/1523-0430(06-098)[BREEN]2.0.CO;2
Libraries: ACU

This study explores the physical, chemical and microclimatological properties of soils along a High Arctic glacier foreland and adjacent moraine in relation to the development of biological soil crusts. We examine various edaphic properties: soil temperature, volumetric water content, organic carbon content, and texture in surface samples (~1 cm) with and without a cover of biological soil crust as well as changes in nitrogen, phosphorus, potassium, organic carbon, pH, volumetric water content, bulk density, and texture in crusted surfaces (<1 cm) and soil cores (5 cm) along a chronosequence following deglaciation. Soil crusts developed within four years of deglaciation and subsequent peaks in crust cover and thickness coincided with an accumulation of nitrogen and organic carbon in the crust. Crusted surfaces had significantly higher volumetric water content, organic carbon, a greater silt and clay fraction, and lower temperature compared to uncrusted soils. A steady supply of water from glacier melt promoted rapid development of biological soil crusts, creating an edaphic environment with enhanced moisture and nutrient properties which contributed to the high rate of vascular plant succession previously observed on this foreland. Results presented in this study are compared with edaphic conditions at other circumpolar sites and glacier forelands. (Au)

C, H, I, F, A, E
Atmospheric temperature; Carbon; Cores; Cyanophyceae; Deglaciation; Density; Glacial deposits; Glacial melt waters; Glacial transport; Glaciers; Microclimatology; Mosses; Nitrogen; Phosphorus; Plant distribution; Plant nutrition; Plant succession; Plant-soil relationships; Potassium; Soil microorganisms; Soil moisture; Soil pH; Soil temperature; Soil texture; Soils; Spatial distribution; Thickness

G0813
Sverdrup Pass, Nunavut; Teardrop Glacier, Nunavut


Observation of rapid drainage system development by thermal erosion of ice wedges on Bylot Island, Canadian Arctic Archipelago   /   Fortier, D.   Allard, M.   Shur, Y.
(Permafrost and periglacial processes, v. 18, no. 3, July/Sept. 2007, p. 229-243, ill., maps)
(PCSP/PPCP contribution, no. 023-07)
References.
ASTIS record 74229.
Languages: English
Web: doi:10.1002/ppp.595
Libraries: ACU

Rapid development of a new drainage system was observed on Bylot Island. A 750-m long gully system was eroded in four years. The process was initiated by the formation of sinkholes eroded in ice wedges by runoff flowing into open frost cracks. The sinkholes evolved into underground tunnels cut in the ice-wedge network and the ice-rich permafrost. Widening of tunnels was followed by subsidence and collapse of their roofs and the development of open gullies. The drainage generally developed as the shortest line along the regional slope with some deviations caused by collapse of blocks of soil which temporarily obstructed the water flow. Retrogressive scarps exposed to flowing water retreated at maximum rates of up to 5 m/day for a total of 15 to 50m during the summer. Scarps exposed to atmospheric heat and solar radiation retreated between 2.5 and 40m over four summers with a mean of 15.5 m. Such slopes had nearly stabilised after four years with a retreat rate of only a few centimetres per year in the last year of observation. (Au)

C, F, E, A
Boreholes; Drainage; Erosion; Frost action; Frozen ground; Ice wedges; Mapping; Mass wasting; Patterned ground; Permafrost; Precipitation (Meteorology); River discharges; Runoff; Slopes; Snowmelt; Solar radiation; Stratigraphy; Thaw settlement; Thermal regimes

G0813
Bylot Island, Nunavut


Identification of coherent links between interannual sedimentary structures and daily meteorological observations in Arctic proglacial lacustrine varves : potentials and limitations   /   Chutko, K.J.   Lamoureux, S.F.
(Canadian journal of earth sciences, v. 45, no. 1, Jan. 2008, p. 1-13, ill., maps)
(PCSP/PPCP contribution, no. 025-07)
References.
ASTIS record 74146.
Languages: English
Web: doi:10.1139/e07-070
Libraries: ACU

Proglacial lacustrine sediments from High Arctic Lake R (76°17.9'N, 90°59.3'W, unofficial name) are shown to be annually laminated (varved) and contain a variety of subannual structures. The formation of the subannual structures (and overall varve) was controlled by a combination of meteorologic (temperature and rainfall) and geomorphic factors. Using a training set of the ten thickest varves in the 38-year sedimentary record, a heuristic model was developed to link subannual structures with regional meteorological conditions. Within the training set, significant correlations were shown between subannual structure thickness and the magnitude of the corresponding melt event, defined as a period of continuously positive temperature. However, these correlations deteriorated as the varves progressively thinned, and several varves exhibited no relationship between their subannual structures and respective meteorological conditions. Grain size analyses showed that the thin varves were significantly finer than the thick varves and are inferred to reflect changed sediment inflow patterns that altered deposition and reduced the fidelity of the model. Despite these complexities, this study identified the potential to produce long-term, subannual reconstructions of weather conditions. Model results revealed the limitations of simple varve-meteorology relationships, as well as identified necessary environmental and sampling conditions required to produce a more robust model for future applications. (Au)

B, E, F, A
Atmospheric temperature; Bathymetry; Bottom sediments; Cesium; Clay; Cores; Effects of climate on ice; Effects of climate on snow; Geomorphology; Glacial melt waters; Glacier lakes; Glaciers; Melting; Radioactive dating; Rain; River discharges; Runoff; Seasonal variations; Sediment transport; Sedimentary structures; Sedimentation; Silt; Size; Snowmelt; Stratigraphy; Stream flow; Thickness

G0813
Colin Archer Peninsula, Nunavut


Systematics of North American Arctic diploid Puccinellia (Poaceae) : morphology, DNA content, and AFLP markers   /   Consaul, L.L.   Gillespie, L.J.   Waterway, M.J.
(Systematic botany, v. 33, no. 2, 2008, p. 251-261, ill., maps)
(PCSP/PPCP contribution, no. 027-07)
Appendices.
References.
ASTIS record 76130.
Languages: English
Web: doi:10.1600/036364408784571662
Libraries: ACU

Alkali grasses (Puccinellia) are temperate and arctic grasses of coastal and alkaline habitats, with ploidy levels that range from diploid to octoploid. This paper investigates the species limits of diploid alkali grasses in the North American Arctic. We used flow cytometry to confirm that four to seven of the 13–19 initially recognized taxa in the North American Arctic are diploid. Multivariate analyses of both morphological and amplified fragment length polymorphism (AFLP) data were congruent in resolving five or six diploid species: 1) P. arctica of northern and western distribution, including P. agrostidea and P. poacea; 2) a new diploid species from Banks Island, N.W.T., Canada; 3) P. tenella subsp. langeana; 4) P. alaskana, which had been previously treated as a subspecies of P. tenella; and 5) circumpolar (except coastal Beringia) P. vahliana, from which 6) the coastal Beringian endemic P. wrightii is distinguishable only on size and for which subspecies status may be more appropriate. In common garden experiments, eleven of 21 quantitative morphological characters varied significantly between field and common garden, showing phenotypic plasticity that explains much of the difficulty in identification. We present a map showing known geographic ranges of diploid Puccinellia species in the North American Arctic. (Au)

H, C
Biological sampling; Coasts; Genetics; Grasses; Greenhouses; Plant anatomy; Plant collections; Plant distribution; Plant taxonomy; Refugia; Soil pH; Testing; Wildlife habitat

G0812, G081, G06, G10, G0811
Banks Island, N.W.T.; North American Arctic; Yukon


The influence of low-level thermal inversions on estimated melt-season characteristics in the central Canadian Arctic   /   Chutko, K.J.   Lamoureux, S.F.
(International journal of climatology, v. 29, no. 2, Feb. 2009, p. 259-268, ill., map)
(PCSP/PPCP contribution, no. 028-07)
References.
ASTIS record 74230.
Languages: English
Web: doi:10.1002/joc.1722
Libraries: ACU

Daily vertical temperature gradients were examined in order to infer melt-event characteristics at an elevation relevant to basin-scale snow and plateau ice-melt studies in the Canadian Arctic. Surface and upper-air temperature data from Resolute, Cornwallis Island, was used to estimate vertical lapse rates up to 300 m asl, and to identify the presence of inversions at that altitude. Lapse rates vary throughout the melt season and are substantially less than typically published generalized values. Thermal inversions are more frequent during the melt season than in the periods immediately before and after, suggesting a strong control on intraseasonal temperature patterns. In July, the period of maximum temperature in the Arctic, inversion frequency is highest and closely related to calculated melting degree-days. Results show that increased summer mean temperature resulted in a substantial lengthening of estimated melt events, as opposed to increased event intensity. Increased inversion frequency leading to shallower vertical lapse rates since the late 1980s is speculated to be the result of synoptic-scale climate patterns, and is potentially an important meteorological mechanism for enhanced glacial melt since the late 1980s. (Au)

F, A, E
Ablation; Atmospheric pressure; Atmospheric temperature; Effects of climate on ice; Glaciers; Ice caps; Mass balance; Melting; Seasonal variations; Snow; Snowmelt; Spatial distribution; Synoptic climatology; Temporal variations; Thermal regimes; Weather stations; Winds

G0813, G0812
Devon Ice Cap, Nunavut; Manson Icefield, Nunavut; Meighen Ice Cap, Nunavut; Melville South Ice Cap, N.W.T.; North Kent Island, Nunavut; Prince of Wales Icefield, Nunavut; Resolute, Nunavut; White Glacier, Nunavut


Combined oceanic and atmospheric influences on net accumulation of Devon Ice Cap, Nunavut, Canada   /   Colgan, W.   Sharp, M.
(Journal of glaciology, v. 54, no.184, Jan. 2008, p. 28-40, ill., maps)
(PCSP/PPCP contribution, no. 029-07)
References.
ASTIS record 74032.
Languages: English
Web: http://arctic.eas.ualberta.ca/downloads/Colgan%20and%20Sharp%20JGlac%202008.pdf
Web: doi:10.3189/002214308784409044
Libraries: ACU

An annual net accumulation history of the high-elevation region of Devon Ice Cap, Nunavut, Canada, was reconstructed for the period 1963-2003 using five shallow firn cores. Annual net accumulation decreased significantly after 1989. To explain variability in the reconstructed annual net accumulation record, monthly and seasonal moisture-source probabilities were calculated for gridcells throughout the Arctic during 1979-2003. Seasonally, moisture-source probabilities reach a maximum in northern Baffin Bay in late summer/early fall and approach zero throughout the Arctic in winter. Late-summer/early-fall moisture-source probabilities were significantly higher around the North Open Water (NOW) Polynya during the 4 year period of highest annual net accumulation during the 1979-2003 period (1984-87), than during the 4 year period with the lowest annual net accumulation (1994-97). This is due to both a significant decrease in the sea-ice fraction and a significant increase in low-elevation atmospheric transport over the NOW area during the high net accumulation period. Anomalously low net accumulation and anomalously high firnification rates during the 1989-2003 period suggest that a change in ice dynamics, rather than a change in surface mass balance, may explain recent ice-cap thickening observed by laser altimetry. (Au)

F, E, D, G
Accumulation; Atmospheric circulation; Cesium; Chlorine; Cores; Density; Evaporation; Firn; Glacial melt waters; Glacial stratigraphy; Ice caps; Ice cover; Isotopes; Laser profilometry; Mass balance; Mathematical models; Melting; Nitrogen oxides; Ocean-atmosphere interaction; Oxygen; Radioactive dating; Radionuclides; Sea ice; Seasonal variations; Size; Snow metamorphism; Sulphates; Temporal variations; Thickness

G0813, G09, G0815
Baffin Bay-Davis Strait; Devon Ice Cap, Nunavut; Labrador Sea; North Water Polynya, Baffin Bay; Queen Elizabeth Islands waters, N.W.T./Nunavut


Is the high-elevation region of Devon Ice Cap thickening?   /   Colgan, W.   Davis, J.   Sharp, M.
(Journal of glaciology, v. 54, no.186, July 2008, p. 428-436, ill., maps)
(PCSP/PPCP contribution, no. 030-07)
Appendix.
References.
ASTIS record 74033.
Languages: English
Web: http://arctic.eas.ualberta.ca/downloads/colgan%20et%20al%20JGlac%202008.pdf
Web: doi:10.3189/002214308785837084
Libraries: ACU

Devon Ice Cap, Nunavut, Canada, has been losing mass since at least 1960. Laser-altimetry surveys, however, suggest that the high-elevation region (>1200 m) of the ice cap thickened between 1995 and 2000, perhaps because of anomalously high accumulation rates during this period. We derive an independent estimate of thickness change in this region by comparing ~40 year mean annual ne accumulation rates to mean specific outflow rates for 11 drainage basins. The area-averaged rate of thickness change across the whole region is within error of zero (0.01 ±0.12 m w.e./a), but two drainage basins in the northwest are thickening significantly, and two basins in the south are thinning significantly. The laser-altimetry observations are biased towards the drainage basins where we find thickening. Recent changes in the rate of accumulation or the rate of firnification cannot explain the observed thickening, but decreased ice outflow, due to the penetration of Neoglacial cooling to, and subsequent stiffening of, the basal ice, may provide an explanation. Thinning in the south may result from increased ice outflow from basins in which fast flow and basal sliding extend above 1200 m. (Au)

F, A
Accumulation; Cores; Density; Evaporation; Firn; Flow; Geographical positioning systems; Glacial melt waters; Ice caps; Laser profilometry; Mass balance; SAR; Size; Snow metamorphism; Spatial distribution; Temporal variations; Thickness; Topography; Velocity

G0813
Devon Ice Cap, Nunavut


Abrupt environmental change in Canada's northernmost lake inferred from fossil diatom and pigment stratigraphy   /   Antoniades, D.   Crawley, C.   Douglas, M.S.   Pienitz, R.   Andersen, D.   Doran, P.T.   Hawes, I.   Pollard, W.   Vincent, W.F.
(Geophysical research letters, v. 34, no. 18, L18708, Sept. 2007, 5 p., ill., maps)
(PCSP/PPCP contribution, no. 031-07)
References.
ASTIS record 65002.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/218.pdf
Web: doi:10.1029/2007GL030947
Libraries: ACU

An analysis of diatoms and fossil pigments in a sediment core from perennially ice-covered Ward Hunt Lake at latitude 83°N in Nunavut, Canada revealed striking changes in diatom communities and sedimentary pigment concentrations during the last two centuries. Diatoms were found only in the upper 2.5 cm of the sedimentary record, and where present, diatom assemblages were composed almost entirely of Staurosirella pinnata. Photosynthetic pigments were present in low concentrations throughout the sedimentary profile, consistent with the ultra-oligotrophic nutrient status of the lake. Pigment concentrations varied slightly in the lower sections of the core, and began to increase gradually at the 4 cm horizon followed by an increase of two orders of magnitude in the uppermost 2.5 cm. The changes observed in the sedimentary record of Ward Hunt Lake had similar trajectories to those observed post-1850 elsewhere in the circumpolar Arctic, and imply that aquatic communities even in the most extreme northern lakes have been strongly impacted by recent climate warming. (Au)

E, F, J, B, H
Algae; Bottom sediments; Chlorophyll; Climate change; Cores; Cyanophyceae; Diatoms; Effects of temperature on plants; Fresh-water ecology; Growing season; History; Lake ice; Lakes; Palaeoclimatology; Palaeoecology; Palaeontology; Photosynthesis; Phytoplankton; Plant growth; Plant taxonomy; Sedimentation; Stratigraphy; Trace elements

G0813
Alert region, Nunavut; Ward Hunt Island, Nunavut


Multi-proxy record of postglacial environmental change, south-central Melville Island, Northwest Territories, Canada   /   Peros, M.   Gajewski, K.   Paull, T.   Ravindra, R.   Podritske, B.
(Quaternary research, v. 73, no. 2, Mar. 2010, p. 247-258, ill., maps)
(PCSP/PPCP contribution, no. 033-07)
References.
ASTIS record 70567.
Languages: English
Web: doi:10.1016/j.yqres.2009.11.010
Libraries: ACU

A sediment core from Lake BC0l (75°10.945'N, 111°55.181W, 225 m asl) on south-central Melville Island, NWT, Canada, provides the first continuous postglacial environmental record for the region. Fossil pollen results indicate that the postglacial landscape was dominated by Poaceae and Salix, typical of a High Arctic plant community, whereas the Arctic herb Oxyria underwent a gradual increase during the late Holocene. Pollen-based climate reconstructions suggests the presence of a cold and dry period ~12,000 cal yr BP, possibly representing the Younger Dryas, followed by warmer and wetter conditions from 11,000 to 5000 cal yr BP, likely reflective of the Holocene Thermal Maximum. The climate then underwent a gradual cooling and drying from 5000 cal yr BP to the present, suggesting a late Holocene neoglacial cooling. Diatom preservation was poor prior to 5000 cal yr BP, when conditions were warmest, suggesting that diatom dissolution may in part be climatically controlled. Diatom concentrations were highest ~4500 cal yr BP but then decreased substantially by 3500 cal yr BP and remained low before recovering slightly in the 20th century. An abrupt warming occurred during the past 70 yr at the site, although the magnitude of this warming did not exceed that of the early Holocene. (Au)

B, A, E, J, H, F
Alders; Bottom sediments; Carbonates; Chemical properties; Climate change; Cores; Deglaciation; Diatoms; Effects of climate on plants; Grasses; Lakes; Lead; Mosses; Palaeobotany; Palaeoclimatology; Palaeoecology; Palynology; Plant distribution; Polar deserts; Pollen; Primary production (Biology); Radiocarbon dating; Recent epoch; Sedimentation; Silica; Water pH; Willows

G0812, G0813
Baffin Island, Nunavut; Liddon Gulf region, N.W.T.


A new species of alkali grass (Puccinellia, Poaceae) from the western North American Arctic   /   Consaul, L.L.   Gillespie, L.J.   Waterway, M.J.
(Novon (Saint Louis, Mo.), v. 18, no. 1, Feb. 2008, p. 16-20, ill.)
(PCSP/PPCP contribution, no. 035-07)
References.
ASTIS record 73756.
Languages: English
Web: doi:10.3417/2007029
Libraries: ACU

A new species of alkali grass, Puccinellia banksiensis Consaul from Banks Island, Northwest Territories, in the Canadian Arctic, is described and illustrated. This diploid species is most similar to the Russian and Alaskan tetraploid P. hauptiana (Trinius ex V.I. Krecznetowicz) Kitagawa, from which it differs by having dense panicles with erect branches and palea keels with curly hairs in the proximal half; to the Siberian species P. neglecta (Tzvelev) Bubnova, which is larger with less dense inflorescences and wider leaves; and to the circumpolar hexaploid P. angustata (R. Br.) E. L. Rand & Redfield, from which it differs by having smaller spikelets and florets. It differs from other Puccinellia Parlatore species on Banks Island and the northern coast of Alaska by having lemmas shorter than 2.7 mm with scabrous apical margins and anthers shorter than 0.9 mm. Although morphology suggests a close relationship with P. angustata, P. hauptiana, and P. neglecta, genetic evidence suggests it is a distinct species. It is local and rare, and grows in low-elevation, Dryas L.-dominated tundra beside coastal lakes. (Au)

H, J
Endangered species; Genetics; Grasses; Identification; Plant anatomy; Plant collections; Plant distribution; Plant ecology; Plant growth; Plant taxonomy; Tundra ecology

G0812, G06, G14
Alaska, Northern; Egg River region, N.W.T.; Masik River region, N.W.T.; Russian Arctic


Finding the right home : distribution of food resources and terrain characteristics influence selection of denning sites and reproductive dens in arctic foxes   /   Szor, G.   Berteaux, D.   Gauthier, G.
(Polar biology, v. 31, no. 3, Feb. 2008, p. 351-362, ill., maps)
(PCSP/PPCP contribution, no. 037-07)
References.
Supplementary material available online.
ASTIS record 74034.
Languages: English
Web: doi:10.1007/s00300-007-0364-1
Libraries: ACU

We examined 83 arctic fox (Alopex lagopus) dens on Bylot Island (Canada) during the summers of 2003-2005, to determine how arctic foxes select a denning site among potential sites, and a breeding den among existing dens. We compared denning sites to random locations in a 425 km² study area (landscape scale) and to other potential denning sites in a 100 m radius (local scale). Dens were located on mounds or in slopes and were closer to streams than expected. Sites with low snow cover in spring, high ground temperature, high depth to permafrost, and steep and southerly exposed slopes were preferred. Of the 83 dens, 27 were used at least once for reproduction from 2003 to 2005. We show with a resource selection function analysis that an attractive force (distribution of food resources) and an apparently repulsive one (presence of other dens in the vicinity) affected selection of dens for reproduction. We generate testable hypotheses regarding the influence of food and social factors on the denning ecology of arctic foxes. (Au)

I, J, A, C, F
Active layer; Animal distribution; Animal ecology; Animal food; Animal reproduction; Animal waste products; Arctic foxes; Aspect; Bird nesting; Denning; Geographical positioning systems; Greater Snow Geese; Lemmings; Plant distribution; Plants (Biology); Rivers; Slopes; Snow; Soil moisture; Soil temperature; Soil texture; Thickness; Topography; Wildlife habitat

G0813
Bylot Island, Nunavut


Simulated heat storage in a perennially ice-covered High Arctic lake : sensitivity to climate change   /   Vincent, A.C.   Mueller, D.R.   Vincent, W.F.
(Journal of geophysical research, v.113, no. C4, C04036, Apr. 2008, 11 p., ill., maps)
(PCSP/PPCP contribution, no. 038-07)
References.
ASTIS record 65003.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/230.pdf
Web: doi:10.1029/2007JC004360
Libraries: ACU

Perennially ice-covered, meromictic lakes occur along the northern coast of Ellesmere Island in the Canadian high Arctic and have distinctive conductivity and temperature profiles. They are salinity stratified and have deep thermal maxima that persist throughout the year at temperatures up to 60°C above the winter minimum in the overlying atmosphere. Heat transfer in one of these lakes (Lake A, latitude 83.0°N, longitude 75.4°W) was simulated using a high spatial resolution model based on a one-dimensional heat diffusion and radiative transfer equation, which was solved through numerical integration. Boundary conditions were forced using climate data from an automated weather station installed next to the lake. There was a good fit between simulated and observed water column temperatures, including the midwater temperature maximum of 8.5°C, after 63 years of heating (RMSE = 0.10°C). This suggests that Lake A became ice-free in the 1940s, a known period of intense warming of the circumpolar Arctic. The model was sensitive to forcing by photosynthetically active radiation (PAR, 400-700 nm), in addition to optically related parameters such as surface reflectance, snow and ice cover, and the PAR diffuse attenuation coefficient. The unusual thermal structure is affected by stratified layers of pigmented microbial communities, which enhance the absorption of solar radiation. Simulation of ice-free summers revealed that the lake's thermal profile would lose its characteristic shape over several decades and that ongoing climate change could reduce the thermal maximum from 8.5° to 4°C within 50 years. (Au)

E, G, F, H, V, J
Ablation; Boundary layers; Climate change; Heat budgets; Heat transmission; History; Lake ice; Lake stratification; Lakes; Mathematical models; Melting; Microbial ecology; Oligotrophic lakes; Optical properties; Photosynthesis; Seasonal variations; Snow; Solar radiation; Surface properties; Temperature; Temporal variations; Thermal properties; Thermal regimes; Thickness; Weather stations

G0813, G15
Bonney, Lake, Antarctic regions; Ellesmere Island, Nunavut; Marvin Peninsula, Nunavut; Vanda, Lake, Antarctic regions


Evaluating the influence of environmental and spatial variables on diatom species distributions from Melville Island (Canadian High Arctic)   /   Keatley, B.E.   Douglas, M.S.V.   Smol, J.P.
(Botany, v. 86, no. 1, Jan. 2008, p. 76-90, ill., maps)
(PCSP/PPCP contribution, no. 039-07)
References.
ASTIS record 65816.
Languages: English
Web: doi:10.1139/B07-118
Libraries: ACU

Diatom species assemblages were identified and enumerated from the surface sediments of 45 lakes and ponds across a wide spectrum of spatial and environmental gradients on Melville Island, Nunavut/N.W.T, Arctic Canada. Whereas the most common taxa were similar to those recorded elsewhere in the Canadian High Arctic, significant differences in assemblages existed between sites located in the different bioclimatic zones of Melville Island. For example, taxa recorded in the most lushly vegetated bioclimatic zone were similar to those found in lushly vegetated regions elsewhere in the Canadian Arctic Archipelago, and generally different from diatoms in the poorly vegetated regions on Melville Island. Of the measured environmental variables, pH, specific conductivity, surface area, elevation, and chlorophyll a explained significant portions of the variance in diatom assemblage composition at the scale of the entire island. However, only total dissolved nitrogen was an important explanatory variable within the most lushly vegetated bioclimatic zone. The strongest ecological relationship was between diatoms and pH, and regression and calibration by weighted averaging produced predictive models with r²boot of 0.432 to 0.746 and RMSEP of 0.341 to 0.242. Spatial factors were of little importance, confirming that diatoms are not likely to be dispersal limited, at least at the landscape scale explored in this study. (Au)

H, F, J, B
Benthos; Bioclimatology; Bottom sediments; Carbon; Chlorophyll; Diatoms; Electrical properties; Fresh-water biology; Lakes; Nitrogen; Palaeoclimatology; Phosphorus; Plant distribution; Silica; Size; Temperature; Topography; Tundra ponds; Water pH

G0813, G0812
Melville Island, N.W.T./Nunavut


Inflow and lake controls on short-term mass accumulation and sedimentary particle size in a High Arctic lake : implications for interpreting varved lacustrine sedimentary records   /   Cockburn, J.M.H.   Lamoureux, S.F.
(Journal of paleolimnology, v. 40, no. 3, Oct. 2008, p. 923-942, ill., maps)
(PCSP/PPCP contribution, no. 041-07)
References.
ASTIS record 65620.
Languages: English
Web: doi:10.1007/s10933-008-9207-5
Libraries: ACU

Sedimentary processes were monitored in a varved lake in the Canadian High Arctic through three melt seasons and revealed that seasonal sediment deposition rates were highly dependent on short-lived inflow events driven by high suspended sediment concentrations that varied with runoff intensity. Our results illustrate that in accordance with the suspended sediment discharge into the lake, the rate of sediment accumulation changed over short distances down-lake, in a given year. This result indicates that there is a rate and accumulation dependence on short-lived, intense inflow conditions. In addition, there was strong evidence for substantial decoupling between deposition rate and mean grain size of sedimentary deposits. These results have important implications for paleoclimate interpretation of annually laminated sedimentary records from dynamic lake environments and suggest that grain size measures may not be representative proxies of inflow competence. Grain size indices based on a measure of the coarser fraction, rather than the bulk sediment, may be more appropriate to use as a link between contemporary runoff processes and sedimentary characteristics. (Au)

B, F, C, E
Atmospheric temperature; Bottom sediments; Lake ice; Lakes; Meteorology; Palaeoclimatology; River discharges; Runoff; Seasonal variations; Sedimentation; Snow; Snow hydrology; Snow water equivalent; Snowmelt; Soil texture; Suspended solids; Temporal variations

G0813
Bounty, Cape, region, Nunavut


Limnological properties of permafrost thaw ponds in northeastern Canada   /   Breton, J.   Vallières, C.   Laurion, I.
(Canadian journal of fisheries and aquatic sciences, v. 66, no. 10, Oct. 2009, p.1635-1648, ill., map)
(PCSP/PPCP contribution, no. 042-07)
References.
ASTIS record 70400.
Languages: English
Web: doi:10.1139/F09-108
Libraries: ACU

Arctic warming has recently accelerated, triggering the formation of thaw ponds and the mobilization of a carbon pool that has accumulated over thousands of years. A survey of 46 thaw ponds in the Canadian arctic and subarctic regions showed that these ecosystems have high concentrations of dissolved organic matter (DOM) and nutrients and are relatively productive. This activity was reflected in the optical properties of DOM that indicated a dominance of allochthonous sources but a significant contribution of low molecular weight compounds. Several subarctic ponds were stratified in summer, resulting in a hypoxic hypolimnion. Most ponds were supersaturated in CO2 and CH4, with higher gas concentrations in bottom waters. However, arctic thaw ponds colonized by benthic microbial mats showed lower CO2 concentrations, likely caused by active photosynthesis. CO2 was correlated with both the quantity and the optical properties of DOM, suggesting the significant role of dissolved compounds from melting organic soils and catchment vegetation on the balance between heterotrophy and autotrophy. The large variability observed in limnological properties of this series of ponds precludes generalisations about their role in greenhouse gas production. However, the fact that all thaw ponds were supersaturated in CH4 underscores the importance of estimating their global significance. (Au)

C, F, E, I, H, J, A
Algae; Bacteria; Bathymetry; Biological sampling; Carbon; Carbon dioxide; Chlorophyll; Climate change; Cyanophyceae; Dissolved organic carbon; Effects of climate on permafrost; Environmental impacts; Fresh-water ecology; Gases; Lake stratification; Lakes; Metabolism; Methane; Microbial ecology; Microorganisms; Nitrogen oxides; Optical properties; Oxygen; Palsas; Peat; Permafrost; Phosphorus; Photosynthesis; Plankton; Plant distribution; Plant nutrition; Plants (Biology); Soils; Spatial distribution; Suspended solids; Taiga ecology; Temperature; Thawing; Thermokarst; Tundra ecology; Tundra ponds; Water pH

G0826, G0813
Boniface, Rivière, region, Québec; Bylot Island, Nunavut; Kuujjuarapik region, Québec; Sheldrake, Rivière, region, Québec


A simple and effective method for preserving the sediment-water interface of sediment cores during transport   /   Tomkins, J.D.   Antoniades, D.   Lamoureux, S.F.   Vincent, W.F.
(Journal of paleolimnology, v. 40, no. 1, July 2008, p. 577-582, ill.)
(PCSP/PPCP contribution, no. 043-07)
References.
ASTIS record 65001.
Languages: English
Web: doi:10.1007/s10933-007-9175-1
Libraries: ACU

We describe a method for preserving the upper sediments of fragile sediment cores during transport from field sites and assess potential effects on subsequent laboratory analyses. This method addresses the need to minimize disturbance to the surfaces of unfrozen sediment cores used for paleoenvironmental or other high-resolution sedimentological analyses during transport. A polymer gel (sodium polyacrylate) applied above the sediment surface acts as a barrier to movement while also preserving surface undulations. The gel seal can preserve even exceptionally fine sedimentary structures (<0.2 mm) in the upper sediments of lacustrine and fiord sediment cores, but may react with organic material (e.g. algal mats) present on some sediment surfaces. This reaction creates an adhesive layer at the gel's base but it can be handled effectively during sampling. The gel seal minimizes surface deformation and preserves surficial sediments better than traditional seals made of water-absorbent floral foam, wax or paper towel. In addition to permitting detailed sedimentary and subfossil investigations of the sediment-water interface, this method shows no detectable effects on measurements of total organic carbon or total nitrogen values in the sediment. This method is inexpensive, non-hazardous and applicable to many coring systems and sediment types. (Au)

B, J, L
Bottom sediments; Carbon; Composition; Cores; Coring; Deformation; Density; Equipment and supplies; Fjords; Lakes; Logistics; Measurement; Nitrogen; Palaeoecology; Soil chemistry; Soil moisture; Stratigraphy; Testing; Transportation

G03, G0813
Ayles Fiord, Nunavut; Ellesmere Island, Nunavut; Markham Fiord, Nunavut


Predator behaviour and predation risk in the heterogeneous Arctic environment   /   Lecomte, N.   Careau, V.   Gauthier, G.   Giroux, J.-F.
(Journal of animal ecology, v. 77, no. 3, May 2008, p. 439-447, ill.)
(PCSP/PPCP contribution, no. 044-07)
References.
ASTIS record 74035.
Languages: English
Web: doi:10.1111/j.1365-2656.2008.01354.x
Libraries: ACU

SUMMARY: 1) Habitat heterogeneity and predator behaviour can strongly affect predator-prey interactions but these factors are rarely considered simultaneously, especially when systems encompass multiple predators and prey. 2) In the Arctic, greater snow geese Anser caerulescens atlanticus L. nest in two structurally different habitats: wetlands that form intricate networks of water channels, and mesic tundra where such obstacles are absent. In this heterogeneous environment, goose eggs are exposed to two types of predators: the arctic fox Vulpes lagopus L. and a diversity of avian predators. We hypothesized that, contrary to birds, the hunting ability of foxes would be impaired by the structurally complex wetland habitat, resulting in a lower predation risk for goose eggs. 3) In addition, lemmings, the main prey of foxes, show strong population cycles. We thus further examined how their fluctuations influenced the interaction between habitat heterogeneity and fox predation on goose eggs. 4) An experimental approach with artificial nests suggested that foxes were faster than avian predators to find unattended goose nests in mesic tundra whereas the reverse was true in wetlands. Foxes spent 3.5 times more time between consecutive attacks on real goose nests in wetlands than in mesic tundra. Their attacks on goose nests were also half as successful in wetlands than in mesic tundra whereas no difference was found for avian predators. 5) Nesting success in wetlands (65%) was higher than in mesic tundra (56%) but the difference between habitats increased during lemming crashes (15%) compared to other phases of the cycle (5%). Nests located at the edge of wetland patches were also less successful than central ones, suggesting a gradient in accessibility of goose nests in wetlands for foxes. 6 Our study shows that the structural complexity of wetlands decreases predation risk from foxes but not avian predators in arctic-nesting birds. Our results also demonstrate that cyclic lemming populations indirectly alter the spatial distribution of productive nests due to a complex interaction between habitat structure, prey-switching and foraging success of foxes. (Au)

I, J
Animal behaviour; Animal distribution; Animal food; Animal population; Bird nesting; Birds; Greater Snow Geese; Lemmings; Predation; Temporal variations; Wetlands; Wildlife habitat

G0813
Bylot Island, Nunavut


Seasonal dynamics of dissolved nitrogen exports from two High Arctic watersheds, Melville Island, Canada   /   Lafrenière, M.   Lamoureux, S.
(Hydrology research, v. 39, no. 4, 2008, p. 323-335, ill., maps)
(PCSP/PPCP contribution, no. 045-07)
References.
ASTIS record 65647.
Languages: English
Web: doi:10.2166/nh.2008.008
Libraries: ACU

This study examines the magnitude and seasonal patterns of dissolved N export during the 2006 melt season from two small watersheds on Melville Island, in the Canadian High Arctic. The dominant N species was dissolved organic nitrogen (DON), comprising >80% of the seasonal nitrogen flux from both rivers. The total DON and dissolved inorganic nitrogen (DIN, (NH4)+ + (NO3)-) yields from the catchments were similar (183 and 204 kg DON, and 46-42 kg DIN): however, on a per unit area basis the West catchment had greater yields of both DON and DIN. There were also differences in the temporal patterns and concentrations of the N species between the catchments, which may be a function of inter-catchment differences in vegetation cover. Low end-of-season DIN concentrations in the West river suggest there is strong biogeochemical retention of inorganic N in this catchment during the growing season relative to the East catchment, where stream (NO3)- concentrations increase through July. A decrease in DOC:DON ratios in the East river at the end of season also indicates a change in the composition of dissolved organic matter in this river that is not evident in the West river. The results illustrate that there can be large differences in the processes controlling nitrogen between two adjacent and similar catchments. (Au)

F, H, J, E
Atmospheric temperature; Carbon; Chromatography; Dissolved organic carbon; Fresh-water ecology; Growing season; Hydrology; Microorganisms; Nitrogen; Nitrogen cycling; Plant distribution; Plant growth; Plant nutrition; Precipitation (Meteorology); River discharges; Runoff; Seasonal variations; Snow; Snow hydrology; Snow water equivalent; Snowmelt; Spatial distribution; Stream flow; Temporal variations; Thickness; Watersheds; Weather stations

G0813
Bounty, Cape, region, Nunavut


Hoarding of pulsed resources : temporal variations in egg-caching by arctic fox   /   Careau, V.   Lecomte, N.   Bêty, J.   Giroux, J.-F.   Gauthier, G.   Berteaux, D.
(Écoscience, v. 15, no 2, June 2008, p. 268-276, ill.)
(PCSP/PPCP contribution, no. 046-07)
References.
ASTIS record 74036.
Languages: English
Web: doi:10.2980/15-2-3097
Libraries: ACU

Resource pulses are common in various ecosystems and often have large impacts on ecosystem functioning. Many animals hoard food during resource pulses, yet how this behaviour affects pulse diffusion through trophic levels is poorly known because of a lack of individual-based studies. Our objective was to examine how the hoarding behaviour of arctic foxes (Alopex lagopus) preying on a seasonal pulsed resource (goose eggs) was affected by annual and seasonal changes in resource availability. We monitored foraging behaviour of foxes in a greater snow goose (Chen caerulescens atlanticus) colony during 8 nesting seasons that covered 2 lemming cycles. The number of goose eggs taken and cached per hour by foxes declined 6-fold from laying to hatching, while the proportion of eggs cached remained constant. In contrast, the proportion of eggs cached by foxes fluctuated in response to the annual lemming cycle independently of the seasonal pulse of goose eggs. Foxes cached the majority of eggs taken (>90%) when lemming abundance was high or moderate but only 40% during the low phase of the cycle. This likely occurred because foxes consumed a greater proportion of goose eggs to fulfill their energy requirement at low lemming abundance. Our study clearly illustrates a behavioural mechanism that extends the energetic benefits of a resource pulse. The hoarding behaviour of the main predator enhances the allochthonous nutrients input brought by migrating birds from the south into the arctic terrestrial ecosystem. This could increase average predator density and promote indirect interactions among prey. (Au)

I, J
Animal behaviour; Animal ecology; Animal food; Animal population; Arctic foxes; Bird nesting; Greater Snow Geese; Lemmings; Predation; Seasonal variations; Temporal variations

G0813
Bylot Island, Nunavut


A record of climate over the last millennium based on varved lake sediments from the Canadian High Arctic   /   Besonen, M.R.   Patridge, W.   Bradley, R.S.   Francus, P.   Stoner, J.S.   Abbott, M.B.
(Holocene, v. 18, no. 1, Jan. 2008, p. 169-180, ill., maps)
(PCSP/PPCP contribution, no. 048-07)
Indexed a PDF file from the Web.
References.
ASTIS record 73525.
Languages: English
Web: doi:10.1177/0959683607085607
Libraries: ACU

A varved sediment record that extends back over the last millennium was recovered from Lower Murray Lake, northern Ellesmere Island, Nunavut, Canada (81°20'N, 69°30'W). Flatbed scan images and backscattered electron images were analysed to provide varve thickness and other quantitative sedimentary indices on an annual basis. In many studies of lakes from the High Arctic, varve thickness is a good proxy for summer temperature and we interpret the Lower Murray Lake varves in this way. On that basis, the Lower Murray Lake varve thickness record suggests that summer temperatures in recent decades were among the warmest of the last millennium, comparable with conditions that last occurred in the early twelfth and late thirteenth centuries, but estimates based on the sediment accumulation rate do not show such a recent increase. The coldest conditions of the 'Little Ice Age' were experienced from ~AD 1700 to the mid-nineteenth century, when extensive ice cover on the lake led to widespread anoxic conditions in the deepest parts of the lake basin. An overall decline in median grain size over the last 1000 years indicates a reduction in the energy available to transport sediment to the lake. Many of these features of the record are also observed in other palaeoclimatic records from the North American Arctic. The very recent appearance of the diatom Campylodiscus, which was not observed throughout the record of the last millennium, suggests that a new threshold in the ontogenetic development of the lake has now been passed. (Au)

B, F, C, E, H, I, G
Atmospheric temperature; Bottom sediments; Climate change; Climatology; Cores; Diatoms; Erosion; Glacial deposits; Hydrology; Ice cover; Instruments; Lake ice; Lakes; Mathematical models; Palaeobotany; Palaeoclimatology; Palaeomagnetism; Palaeontology; Petrography; Physical properties; Precipitation (Meteorology); Radioactive dating; Radiocarbon dating; Radionuclides; Runoff; Seasonal variations; Sediment transport; Sedimentation; Sediments (Geology); Snow hydrology; Snowmelt; Stratigraphy; Temporal variations; Weather stations

G0813
Ellesmere Island, Nunavut; Eureka, Nunavut; Murray Lake (81 20 N, 69 34 W), Nunavut; Resolute, Nunavut; Sawtooth Lake, Nunavut; Tuborg, Lake, Nunavut


Holocene climate change and its effect on lake ecosystem production on northern Victoria Island, Canadian Arctic   /   Fortin, M.-C.   Gajewski, K.
(Journal of paleolimnology, v. 43, no. 2, Feb. 2010, p. 219-234, ill., maps)
(PCSP/PPCP contribution, no. 049-07)
References.
ASTIS record 70560.
Languages: English
Web: doi:10.1007/s10933-009-9326-7
Libraries: ACU

A multi-proxy paleoenvironmental study from Lake WB02 (72.29°N, 109.87°W) on Northern Victoria Island, Nunavut, Canada provides an 8.4-ka record of chironomid and ecosystem production. Mean July air temperatures for this region during the Holocene were inferred from the fossil record. The chironomid assemblages contained 33 taxa and were dominated by Paracladius and Heterotrissocladius maeaeri-type. Primary production and chironomid food availability inferred from sediment biogenic silica and loss on ignition at 550°C, and chironomid concentrations, all exhibited synchronous patterns of change through time. Similar to other climate records from across the Arctic, the sediment and fossil data from Lake WB02 support the hypothesis of a warm and productive early to middle Holocene, a cool and generally unproductive middle to late Holocene and a return to a warmer, more productive environment in the past 100 years. Mean July air temperature reconstructions based on both the modern analogue technique (MAT) and weighted averaging partial least squares regression (WAPLS), however, failed to reflect these same changes. The difference between the qualitative and quantitative environmental reconstructions may be due to the restrictions associated with the use of these inference tools, the effects of which are more significant in unproductive ecosystems such as Arctic lakes. (Au)

B, E, F, J, H, I
Animal taxonomy; Atmospheric temperature; Biological productivity; Bottom sediments; Carbonates; Cesium; Chironomidae; Climate change; Cores; Diatoms; Fresh-water ecology; Lakes; Lead; Mosses; Palaeoclimatology; Palaeoecology; Palaeontology; Pollen; Primary production (Biology); Radiocarbon dating; Recent epoch; Seasonal variations; Sedimentation; Temporal variations; Trophic levels; Water pH

G0813, G0812
Baffin Island, Nunavut; Ulukhaktok, N.W.T.; Victoria Island, N.W.T./Nunavut


Breeding status, contaminant burden and helminth parasites of Northern Fulmars "Fulmarus glacialis" from the Canadian High Arctic   /   Mallory, M.L.   McLaughlin, J.D.   Forbes, M.R.
(Ibis, v.149, no. 2, Apr. 2007, p. 338-344, ill.)
(PCSP/PPCP contribution, no. 053-07)
References.
ASTIS record 75259.
Languages: English
Web: doi:10.1111/j.1474-919X.2006.00636.x
Libraries: ACU

We studied the relationship between contaminant concentrations in livers, endohelminth prevalence and physiological indices of chronic stress (spleen size, heterophil/lymphocyte ratios) in Northern Fulmars "Fulmarus glacialis" collected during the breeding season in Nunavut, Canada. No blood parasites were found, similar to reports for other petrel species elsewhere. However, 54% of Fulmars had gastrointestinal helminths, principally cestodes (52% prevalence, mean intensity of 11 worms), nematodes (34% prevalence, 3.6 worms) and acanthocephalans (3%, eight worms). Both prevalence and intensity of helminth infections were lower for Arctic Fulmars than for Fulmars and other petrels found in southern parts of the species' range. Spleen size was not significantly related to either contaminant concentration or presence of parasites, suggesting that Fulmar health was generally unaffected by contaminant and parasite levels at the colony. However, we cannot rule out the possibility that Fulmars with higher parasitaemias or contaminant loads were in poorer condition and did not attend the breeding colony. (Au)

J, I
Acanthocephala; Animal health; Animal physiology; Animal reproduction; Biological sampling; Bird nesting; Blood; Chlordanes; DDT; Dieldrin; Fulmars; Gender differences; HCB; HCH; Internal organs; Mirex; Necropsy; Nematoda; Parasites; PCBs; Pollution; POPs; Size; Tapeworms; Toxicity

G0813
Vera, Cape, Nunavut


Temporal trends of organochlorines and mercury in seabird eggs from the Canadian Arctic, 1975-2003   /   Braune, B.M.
(Environmental pollution, v.148, no. 2, July 2007, p. 599-613, ill., maps)
(PCSP/PPCP contribution, no. 054-07)
References.
ASTIS record 62427.
Languages: English
Web: doi:10.1016/j.envpol.2006.11.024
Libraries: ACU

Organochlorine pesticides, PCBs, total mercury and selenium were measured in eggs of thick-billed murres, northern fulmars and black-legged kittiwakes collected from Prince Leopold Island in the Canadian High Arctic between 1975 and 2003. The primary organochlorines found were Sigma PCB, p,p'-DDE, oxychlordane, and hexachlorobenzene (HCB). Most of organochlorines analyzed showed either significant declines or no significant change between 1975 and 2003 in all three species. However, significant increases were observed for Sigma HCH in the kittiwakes and fulmars, and ß-HCH in the murres and fulmars. Mercury increased significantly in eggs of murres and fulmars, whereas mercury in the kittiwakes did not change significantly over the study period. Statistical analyses included stable-nitrogen isotope ratios (delta 15N) to control for any variation in trophic level over time. Although the contaminant concentrations reported in this study are below published threshold values, mercury and ß-HCH concentrations continue to increase suggesting that continued monitoring is warranted. (Au)

I, J
Animal food; Animal health; Animal migration; Animal reproduction; Bioaccumulation; Biomagnification; Bird nesting; Chlordanes; Chromatography; DDT; Dieldrin; Effects monitoring; Environmental impacts; Fulmars; HCB; HCH; Isotopes; Kittiwakes; Lipids; Logistics; Measurement; Mercury; Mirex; Nitrogen; Organochlorines; PCBs; Pollution; Selenium; Spectroscopy; Temporal variations; Thick-billed Murres; Toxicity; Trophic levels

G0813
Prince Leopold Island, Nunavut


Prevalence of long-chained perfluorinated carboxylates in seabirds from the Canadian Arctic between 1975 and 2004   /   Butt, C.M.   Mabury, S.A.   Muir, D.C.G.   Braune, B.M.
(Environmental science & technology, v. 41, no. 10, May 15, 2007, p.3521-3528, ill.)
(PCSP/PPCP contribution, no. 055-07)
References.
Supporting information available on-line.
ASTIS record 62583.
Languages: English
Web: doi:10.1021/es062710w
Libraries: ACU

Temporal trends in perfluoroalkyl compounds (PFCs) were investigated in liver samples from two seabird species, thick-billed murres (Uria lomvia) and northern fulmars (Fulmaris glacialis), from Prince Leopold Island in the Canadian Arctic. Thick-billed murre samples were from 1975, 1993, and 2004, whereas northern fulmars were from 1975, 1987, 1993, and 2003. Between 8 and 10 individuals were analyzed per year. Analytes included C7-C15 perfluorinated carboxylates (PFCAs) and their suspected precursors, the 8:2 & 10:2 fluorotelomer saturated and unsaturated carboxylates (FTCAs, FTUCAs), C6, C8 (perfluorooctane sulfonate, PFOS), C10 sulfonates, and perfluorooctane sulfonamide (PFOSA). Liver samples were homogenized, liquid-liquid extracted with methyl tert-butyl ether, cleaned-up using hexafluoropropanol, and analyzed by LC-MS/MS. Overall, concentrations in seabirds were lower than those in other marine animals that occupy similar or higher trophic positions. In contrast to most other wildlife samples, PFC profiles were dominated by the PFCAs which comprised 81% and 93% of total PFC profiles in the 2004 thick-billed murre and 2003 northern fulmar samples, respectively. As well, the PFCA profiles were mainly comprised of the C11-C15 PFCAs, which appears to be unique among other wildlife species. PFC concentrations were found to increase significantly from 1975 to 2003/2004. Doubling times in thick-billed murres ranged from 2.3 yrs for perfluoropentadecanoate (PFPA) to 9.9 yrs for perfluorododecanoate (PFDoA), and from 2.5 yrs for PFPA to 11.7 yrs for perfluorodecanoate (PFDA) in northern fulmars. PFCA concentration increases in thick-billed murres were significant for both time periods (1975-1993, 1993-2004), but in northern fulmars appeared to remain steady after 1993. Differences in the temporal trends observed may be the result of differing migratory patterns of the seabirds. Finally, the detection of the 8:2 and 10:2 FTUCAs in seabirds is suggestive of fluorotelomer alcohols as a source of some PFCAs. (Au)

J, I
Animal food; Animal migration; Biological sampling; Environmental impacts; Food chain; Fulmars; Gender differences; Internal organs; Necropsy; Organofluorines; Pollution; Temporal variations; Thick-billed Murres; Trophic levels

G0813
Prince Leopold Island Migratory Bird Sanctuary, Nunavut


Modern and late Holocene retrogressive thaw slump activity on the Yukon Coastal Plain and Herschel Island, Yukon Territory, Canada   /   Lantuit, H.   Pollard, W.H.   Couture, N.   Fritz, M.   Schirrmeister, L.   Meyer, H.   Hubberten, H.-W.
(Permafrost and periglacial processes, v. 23, no. 1, Jan. 2012, p. 39-51, ill., maps)
(PCSP/PPCP contribution, no. 001-08)
References.
Two publications have PCSP/PPCP contribution number 001-08. The other publication is described by ASTIS record 76132.
ASTIS record 76086.
Languages: English
Web: doi:10.1002/ppp.1731
Libraries: ACU

Four retrogressive thaw slumps (RTS) located on Herschel Island and the Yukon coast (King Point) in the western Canadian Arctic were investigated to compare the environmental, sedimentological and geochemical setting and characteristics of zones in active and stabilised slumps and at undisturbed sites. In general, the slope, sedimentology and biogeochemistry of stabilised and undisturbed zones differ, independent of their age or location. Organic carbon contents were lower in slumps than in the surrounding tundra, and the density and compaction of slump sediments were much greater. Radiocarbon dating showed that RTS were likely to have been active around 300 a BP and are undergoing a similar period of increased activity now. This cycle is thought to be controlled more by local geometry, cryostratigraphy and the rate of coastal erosion than by variation in summer temperatures. (Au)

C, B, A, D, H, E, J
Active layer; Aerial photography; Bryophytes; Carbon; Climate change; Coast changes; Density; Dryas; Effects of climate on permafrost; Erosion; Geochemistry; Geographical positioning systems; Geomorphology; Glacial deposits; Grasses; Ground ice; Ocean waves; Permafrost; Plant distribution; Radiocarbon dating; Recent epoch; Satellite photography; Size; Slopes; Soil mechanics; Soil moisture; Soil profiles; Soil texture; Spatial distribution; Storms; Strength; Temporal variations; Thaw flow slides; Thawing; Thermokarst; Thickness; Topography; Willows

G0811
Herschel Island, Yukon; King Point region, Yukon


Origin and characteristics of massive ground ice on Herschel Island (western Canadian Arctic) as revealed by stable water isotope and hydrochemical signatures   /   Fritz, M.   Wetterich, S.   Meyer, H.   Schirrmeister, L.   Lantuit, H.   Pollard, W.H.
(Special issue : stable isotopes and geochemistry of ground ice. Permafrost and periglacial processes, v. 22, no. 1, Jan. 2011, p. 26-38, ill., maps)
(PCSP/PPCP contribution, no. 001-08)
References.
Two publications have PCSP/PPCP contribution number 001-08. The other publication is described by ASTIS record 76086.
ASTIS record 76132.
Languages: English
Web: doi:10.1002/ppp.714
Libraries: ACU

Herschel Island in the southern Beaufort Sea is a push moraine at the northwestern-most limit of the Laurentide Ice Sheet. Stable water isotope (delta 18O, delta D) and hydrochemical studies were applied to two tabular massive ground ice bodies to unravel their genetic origin. Buried glacier ice or basal regelation ice was encountered beneath an ice-rich diamicton with strong glaciotectonic deformation structures. The massive ice isotopic composition was highly depleted in heavy isotopes (mean delta 18O: -33‰; mean delta D: -258‰), suggesting full-glacial conditions during ice formation. Other massive ice of unknown origin with a very large delta 18O range (from -39 to -21‰) was found adjacent to large, striated boulders. A clear freezing slope was present with progressive depletion in heavy isotopes towards the centre of the ice body. Fractionation must have taken place during closed-system freezing, possibly of a glacial meltwater pond. Both massive ground ice bodies exhibited a mixed ion composition suggestive of terrestrial waters with a marine influence. Hydrochemical signatures resemble the Herschel Island sediments that are derived from near-shore marine deposits upthrust by the Laurentide ice. A prolonged contact between water feeding the ice bodies and the surrounding sediment is therefore inferred. (Au)

C, B, A
Active layer; Calcium; Chlorine; Deformation; Deuterium; Folds (Geology); Formation; Geochemistry; Glacial deposits; Glacial epoch; Glacial melt waters; Ground ice; Isotopes; Laurentide Ice Sheet; Magnesium; Moraines; Oxygen-18; Permafrost; Pleistocene epoch; Potassium; Sediments (Geology); Size; Sodium; Spatial distribution; Sulphates; Thaw flow slides; Thermokarst; Thickness

G0811
Herschel Island, Yukon


Climatic effects on the breeding phenology and reproductive success of an Arctic-nesting goose species   /   Dickey, M.-H.   Gauthier, G.   Cadieux, M.-C.
(Global change biology, v. 14, no. 9, Sept. 2008, p.1973-1985, ill.)
(PCSP/PPCP contribution, no. 002-08)
References.
ASTIS record 74239.
Languages: English
Web: doi:10.1111/j.1365-2486.2008.01622.x
Libraries: ACU

Climate warming is pronounced in the Arctic and migratory birds are expected to be among the most affected species. We examined the effects of local and regional climatic variations on the breeding phenology and reproductive success of greater snow geese (Chen caerulescens atlantica), a migratory species nesting in the Canadian Arctic. We used a long-term dataset based on the monitoring of 5447 nests and the measurements of 19 234 goslings over 16 years (1989-2004) on Bylot Island. About 50% of variation in the reproductive phenology of individuals was explained by spring climatic factors. High mean temperatures and, to a lesser extent, low snow cover in spring were associated with an increase in nest density and early egg-laying and hatching dates. High temperature in spring and high early summer rainfall were positively related to nesting success. These effects may result from a reduction in egg predation rate when the density of nesting geese is high and when increased water availability allows females to stay close to their nest during incubation recesses. Summer brood loss and production of young at the end of the summer increased when values of the summer Arctic Oscillation (AO) index were either very positive (low temperatures) or very negative (high temperatures), indicating that these components of the breeding success were most influenced by the regional summer climate. Gosling mass and size near fledging were reduced in years with high spring temperatures. This effect is likely due to a reduced availability of high quality food in years with early spring, either due to food depletion resulting from high brood density or a mismatch between hatching date of goslings and the timing of the peak of plant quality. Our analysis suggests that climate warming should advance the reproductive phenology of geese, but that high spring temperatures and extreme values of the summer AO index may decrease their reproductive success up to fledging. (Au)

I, J, E, F
Age; Animal distribution; Animal food; Animal growth; Animal live-capture; Animal mortality; Animal reproduction; Animal tagging; Atmospheric pressure; Atmospheric temperature; Bioclimatology; Bird nesting; Climate change; Databases; Effects monitoring; Environmental impacts; Greater Snow Geese; Predation; Rain; Seasonal variations; Size; Snow; Temporal variations; Thickness

G0815
Bylot Island, Nunavut


Paleoenvironmental reconstruction of a Middle Miocene forest from the western Canadian Arctic   /   Williams, C.J.   Mendell, E.K.   Murphy, J.   Court, W.M.   Johnson, A.H.   Richter, S.L.
(Palaeogeography, palaeoclimatology, palaeoecology, v.261, no. 1-2, Apr. 2008, p. 160-176, ill., maps)
(PCSP/PPCP contribution, no. 004-08)
References.
ASTIS record 73758.
Languages: English
Web: doi:10.1016/j.palaeo.2008.01.014
Libraries: ACU

Abundant fossil plant remains are preserved in deposits of Middle Miocene age of the Ballast Brook Formation on Banks Island, Northwest Territories, Canada. Intact seed cones, logs, and stumps are preserved in situ as mummified remains and present an opportunity to reconstruct the composition, structure, and productivity of a Pinaceae-dominated forest that once grew north of the Arctic Circle (paleolatitude ca. 74°N). We mapped and measured 78 tree stumps exposed in three dimensions on a 0.12 ha peat layer. An analysis of the wood anatomy and seed cones indicates that a haploxylon pine dominated this lowland forest, although species of both Picea and Glyptostrobus were growing in the swamp as well. Stump diameters ranged from 7 cm to 108 cm (average = 42 cm). We utilized allometric relationships to predict tree heights based on the stump diameters in the fossil forest. Our results indicate that the average tree height of this Miocene forest may have been as large as 21 m. We used stump diameter data and predicted tree height to calculate the parabolic stem volume and stem biomass for the exposed area of fossil forest. Stem biomass (assuming an average wood density of 410 kg/m³) may have been as great as 259 Mg/ha or as little at 202 Mg/ha. The annual ring width of the stem wood sampled in the field was 1.26 mm for Pinus, 1.20 mm for Picea and 0.21 mm for Glyptostrobus. Based on these growth rates, our estimate of biomass sequestered aboveground as wood is at most 3.8 Mg/ha/y. Based on our estimates, these lowland forest communities were of moderate biomass and productivity typical of modern cool temperate forests in North America. (Au)

B, H, E, J
Atmospheric chemistry; Biological productivity; Biomass; Carbon cycling; Cenozoic era; Dendrochronology; Fossil forests; Geology; Mapping; Measurement; Miocene epoch; Palaeobotany; Palaeoclimatology; Palaeoecology; Pines; Plant distribution; Plant growth; Plant physiology; Pliocene epoch; Seeds; Size; Stratigraphy; Taiga ecology; Trees

G0812
Ballast Brook region, N.W.T.; Banks Island, N.W.T.


Systematics of three North American polyploid arctic alkali grasses (Puccinellia, Poaceae) : morphology, ploidy, and AFLP markers   /   Consaul, L.L.   Gillespie, L.J.   Waterway, M.J.
(Botany, v. 86, no. 8, Aug. 2008, p. 916-937, ill., map)
(PCSP/PPCP contribution, no. 006-08)
Appendix.
References.
ASTIS record 66568.
Languages: English
Web: doi:10.1139/B08-073
Libraries: ACU

We used flow cytometry, amplified fragment length polymorphisms (AFLP), and macromorphology from field and common garden specimens to delimit and identify parental taxa of three polyploid species of Puccinellia from the North American Arctic. Tetraploid Puccinellia bruggemannii T.J. Sørensen, hexaploid Puccinellia angustata (R. Br.) E.L. Rand & Redfield, and octoploid Puccinellia andersonii Swallen were generally separable based on ploidy and AFLP pattern, and showed allopolyploid origin. All three shared AFLP bands with at least two diploids and with Puccinellia phryganodes (Trin.) Scribn. & Merr., shown here to have both triploid and tetraploid populations in Canada. Approximately 10% of hexaploid individuals had AFLP patterns that were intermediate between P. angustata and P. bruggemannii, or P. angustata and P. andersonii, and occupied corresponding intermediate positions in morphological ordinations. Geographic distributions provide better support for introgression than for multiple polyploid events to account for these intermediate patterns. In common garden experiments, half of the characters had significantly different values between field and common garden specimens, but these plastic characters varied depending on the species pair analyzed and between experiments. Moreover, several characters were significantly different among species, but these characters were also different in each of the two experiments. Given this variation, we pooled the field and common garden data to determine important key characters by discriminant analysis of species pairs. (Au)

H
Biological sampling; Genetics; Grasses; Identification; Plant anatomy; Plant collections; Plant distribution; Plant growth; Plant taxonomy; Pollen; Size

G0812, G0813, G0827, G0824, G0811, G06, G10
Axel Heiberg Island, Nunavut; Banks Island, N.W.T.; Beechey Island, Nunavut; Churchill region, Manitoba; Cunningham Inlet region, Nunavut; Ellesmere Island, Nunavut; Labrador; Mould Bay region, N.W.T.; Nain region, Labrador; North American Arctic; Resolute region, Nunavut; Tarr Inlet region, Nunavut


Electrical freezing potentials during permafrost aggradation at the Illisarvik drained-lake experiment, western Arctic coast, Canada   /   Parameswaran, V.R.   Burn, C.R.
In: Ninth International Conference on Permafrost / Edited by Douglas L. Kane and Kenneth M. Hinkel. - Fairbanks, Alaska : University of Alaska, Fairbanks, 2008, v. 2, p.1363-1368, ill., maps
(PCSP/PPCP contribution, no. 008-08)
References.
Proceedings available on paper, CD-ROM and the Web.
ASTIS record 73755.
Languages: English
Web: http://www.blue-europa.org/nicop_proceedings/6%20Vol%202%20(1281-1530).pdf
Libraries: ACU

A probe containing a series of electrodes spaced at regular intervals was used to monitor electrical potentials developed across the freezing front during permafrost aggradation at depth in the talik of the Illisarvik drained lake bed. Data were collected from 2000 to 2007. The electrode located at the freezing interface showed a peak electrical potential, commonly of tens of mV, when measured with respect to reference electrodes in the unfrozen or the completely frozen region. The location of the freezing front was consistent with temperature measurements using thermistors installed at these depths. This experiment suggests that, with proper electrode probes and frequent measurements, electrical freezing potentials can be used for monitoring the movement of the freezing front in permafrost areas. (Au)

C
Active layer; Design and construction; Effects monitoring; Electrical properties; Formation; Frozen ground; Ground ice; Instruments; Measurement; Moisture transfer; Permafrost beneath lakes; Soil freezing; Soil temperature; Temporal variations; Testing; Thawing

G0812
Illisarvik Lake, N.W.T.; Richards Island, N.W.T.


Permafrost response to climate warming south of treeline, Mackenzie Delta, Northwest Territories, Canada   /   Kanigan, J.C.N.   Burn, C.R.   Kokelj, S.V.
In: Ninth International Conference on Permafrost / Edited by Douglas L. Kane and Kenneth M. Hinkel. - Fairbanks, Alaska : University of Alaska, Fairbanks, 2008, v. 1, p. 901-906, ill., map
(PCSP/PPCP contribution, no. 009-08)
References.
Proceedings available on paper, CD-ROM and the Web.
ASTIS record 68580.
Languages: English
Web: http://www.blue-europa.org/nicop_proceedings/4%20Vol%201%20(753-xl).pdf
Libraries: ACU

The mean annual ground temperature (MAGT) at two sites in the Mackenzie Delta, south of treeline, has increased by 0.3°C and 0.7°C over the past 40 years. This ground warming is less than reported from the adjacent tundra uplands. The hypothesis that MAGTs in the boreal forest region of the delta may have a reduced response to climate warming due to the thermal influence of numerous water bodies has been investigated with an equilibrium geothermal model. The model indicates that water bodies have a warming influence on MAGTs up to 750 m from the lake or channel. If lake-bottom temperatures do not respond to climate warming, or warm more slowly than ground surface temperatures, then MAGTs at sites close to water bodies will warm more slowly than sites located greater than 750 m away. This may partly explain the apparent dampening of ground thermal responses to climate change in the delta. (Au)

C, F, E, H, J
Bottom sediments; Climate change; Effects of climate on permafrost; Heat transmission; Lakes; Mathematical models; Measurement; Plant cover; Rivers; Soil temperature; Surface temperature; Taiga ecology; Temporal variations; Thermal regimes; Tundra ecology; White spruces

G0812
Inuvik region, N.W.T.; Mackenzie Delta, N.W.T.; Reindeer Station region, N.W.T.


Hydroclimatic and channel snowpack controls over suspended sediment and grain size transport in a High Arctic catchment   /   McDonald, D.M.   Lamoureux, S.F.
(Earth surface processes and landforms, v. 34, no. 3, 15 Mar. 2009, p. 424-436, ill., maps)
(PCSP/PPCP contribution, no. 010-08)
References.
ASTIS record 71850.
Languages: English
Web: doi:10.1002/esp.1751
Libraries: ACU

Temporal variability in suspended sediment delivery processes was studied during three seasons in a 7·9 km² catchment at Cape Bounty, Melville Island, Nunavut in the Canadian High Arctic. Discharge was controlled primarily by the magnitude of snowmelt, with limited inputs from ground ice melt and precipitation. Years with greater snowpack non-linearly increased sediment yield and resulted in seasonal counter-clockwise hysteresis, while a year with low snowpack resulted in reduced sediment yield and clockwise hysteresis, and indicates that sediment was increasingly available after the onset of streamflow. In addition to the event-scale hysteresis observed during the nival discharge peak, diurnal clockwise hysteresis was observed during all three seasons and suggests daily exhaustion of sediment supplies. These results indicate that the channel snowpack plays a primary role over sediment accessibility during the nival discharge peak. Similarly, grain size analysis of suspended material in the river showed that the coarsest mean grain size was transported during the early phase of peak nival discharge and indicates that isolated sources of coarse material were being accessed by high velocity flow. Snowpack is present through the peak nival period and conditions sediment availability by isolating channel sediments from high-energy flow. These results indicate sediment delivery characteristics in small High Arctic catchments reflect complex interactions with channel snowpack and disproportionate responses to flow conditions that differ from glacial and temperate settings. (Au)

F, E, A
Climate change; Diurnal variations; Erosion; Floods; Hydrology; Meteorology; River discharges; Rivers; Seasonal variations; Sediment transport; Sedimentation; Snow; Snow cover; Snow hydrology; Snowmelt; Soil texture; Stream flow; Suspended solids; Temporal variations; Velocity; Watersheds

G0813
Bounty, Cape, region, Nunavut


Paleoecological evidence for transitions between contrasting landforms in a polygon-patterned High Arctic wetland   /   Ellis, C.J.   Rochefort, L.   Gauthier, G.   Pienitz, R.
(Arctic, antarctic, and alpine research, v. 40, no. 4, Nov. 2008, p. 624-637, ill., maps)
(PCSP/PPCP contribution, no. 012-08)
References.
ASTIS record 74253.
Languages: English
Web: doi:10.1657/1523-0430(07-059)[ELLIS]2.0.CO;2
Libraries: ACU

The formation of many arctic wetlands is associated with the occurrence of polygon-patterned permafrost. Existing scenarios to describe and explain surface landforms in arctic wetlands (low-center and high-center polygons and polygon ponds) invoke competing hypotheses: a cyclic succession (the thaw-lake hypothesis) or a linear succession (terrestrialization). Both hypotheses infer the predictable development of polygon-patterned wetlands over millennia. However, very few studies have applied paleoecological techniques to reconstruct long-term succession in tundra wetlands and thereby test the validity of existing hypotheses. This paper uses the paleoecological record of diatoms to investigate long-term development of individual polygons in a High Arctic wetland. Two landform processes were examined: (1) the millennial-scale development of a polygon-pond, and (2) the transition from low-center to erosive high-center polygons. Diatom assemblages were quantified from habitats associated with contrasting landforms in the present-day landscape, and used as an analog to reconstruct past transitions between polygon types. On the basis of this evidence, the paleoecological record does not support either of the existing models describing the predictable succession of polygon landforms in an arctic wetland. Our results indicate a need for greater paleoecological understanding, in combination with in situ observations in present-day geomorphology, in order to identify patterns of polygon wetland development and elucidate the long-term drivers of these landform transitions. (Au)

C, H, J, B, A
Active layer; Algae; Bottom sediments; Cores; Diatoms; Formation; Frost action; Geomorphology; Growth; Ice wedges; Mosses; Palaeoecology; Patterned ground; Peat; Permafrost; Plant distribution; Radiocarbon dating; Soil moisture; Soil profiles; Thawing; Topography; Tundra ponds; Wetlands

G0813
Bylot Island, Nunavut


Fluvial impact of extensive active layer detachments, Cape Bounty, Melville Island, Canada   /   Lamoureux, S.F.   Lafrenière, M.J.
(Arctic, antarctic, and alpine research, v. 41, no. 1, Feb. 2009, p. 59-68, ill., maps)
(PCSP/PPCP contribution, no. 013-08)
References.
ASTIS record 66372.
Languages: English
Web: doi:10.1657/1938-4246(08-030)[LAMOUREUX]2.0.CO;2
Libraries: ACU

Exceptional and persistent warm temperatures recorded during July 2007 at Cape Bounty, Melville Island, Canada (74°54N, 109°35W), resulted in rapid and deep active layer formation. The thickened active layer, together with up to 10.8 mm of rainfall in late July, resulted in widespread active layer detachments across the West watershed during 23-31 July. Mapping indicates that approximately 1.9% of the watershed was directly impacted by disturbances. By contrast, only two small detachments occurred in the adjacent East watershed. The immediate fluvial impact of the detachments was primarily in the form of abrupt, short-lived rises in river turbidity, along with a more gradual increase in discharge and overall turbidity. Sediment transport pulses resulted from the hydrological connection of major detachment slides, most of which were upslope from the main channel. The largest detachment dammed the river over a length of 200 m, and resulted in an upstream pond and prolonged increased sediment transport. In total, the increased sediment transport during the last week of July amounted to an estimated 44.3 Mg, or 18% of the seasonal yield. While the detachments had an immediate and substantial impact on river conditions, erosion of unstable material is likely to have a sustained impact on watershed fluxes in future years. (Au)

F, C, E, A, J
Active layer; Aspect; Atmospheric temperature; Carbon; Climate change; Effects monitoring; Effects of climate on permafrost; Environmental impacts; Erosion; Ground ice; Instruments; Lakes; Mass wasting; Measurement; Permafrost; Rain; River discharges; Rivers; Runoff; Seasonal variations; Sediment transport; Snow; Snow hydrology; Snow surveys; Snowmelt; Soil moisture; Spatial distribution; Stream flow; Suspended solids; Temporal variations; Thaw flow slides; Thawing; Watersheds

G0813
Bounty, Cape, region, Nunavut


Sedimentary pellets as an ice-cover proxy in a High Arctic ice-covered lake   /   Tomkins, J.D.   Lamoureux, S.F.   Antoniades, D.   Vincent, W.F.
(Late Holocene climate and environmental change inferred from Arctic lake sediment / Edited by Darrell Kaufman. Journal of paleolimnology, v. 41, no. 1, Jan. 2009, p. 225-242, ill., maps)
(PCSP/PPCP contribution, no. 014-08)
References.
ASTIS record 66168.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/244.pdf
Web: doi:10.1007/s10933-008-9255-x
Libraries: ACU

Sediment aggregates ("sedimentary pellets") within the sedimentary record of Lake A (83°00' N, 75°30' W), Ellesmere Island, Canada, are used to construct a 1000 year proxy record of ice-cover extent and dynamics on this perennially ice-covered, High Arctic lake. These pellets are interpreted to form during fall or early winter when littoral sediment adheres to ice forming around the lake’s periphery or during summer through the development of anchor ice. The sediment likely collects in ice interstices and is concentrated in the upper ice layers through summer surface ice melt and winter basal ice growth. The pellets remain frozen in the ice until a summer or series of summers with reduced ice cover allows for their deposition across the lake basin. Sedimentary pellet frequency within multiple sediment cores is used to develop a chronology of ice-cover fluctuations. This proxy ice-cover record is largely corroborated by a record of unusual sedimentation in Lake A involving iron-rich, dark-orange to red laminae overlying more diffuse laminae with a lighter hue. This sediment sequence is hypothesized to represent years with reduced ice cover through increased chemocline ventilation and iron deposition. During the past millennium, the most notable period of inferred reduced ice cover is ca. 1891 AD to present. Another period of ice cover mobility is suggested ca. 1582-1774 AD, while persistent ice cover is inferred during the 1800s and prior to 1582 AD. The proxy ice-cover record corresponds well with most regional melt-season proxy temperature and paleoecological records, especially during the 1800s and 1900s. (Au)

B, E, F, J, I, G
Anchor ice; Atmospheric temperature; Bottom sediments; Climate change; Cores; Density; Foraminifera; Formation; Ice caps; Ice cover; Instruments; Lake ice; Lake stratification; Lakes; Measurement; Melting; Meteorology; Palaeoclimatology; Palaeoecology; Palaeomagnetism; Radioactive dating; Radiocarbon dating; Radionuclides; Recent epoch; Sediment transport; Sedimentary structures; Sedimentation; Sediments (Geology); Spectroscopy; Temporal variations; Thickness

G0813
Agassiz Ice Cap, Nunavut; Alert, Nunavut; Devon Ice Cap, Nunavut; Marvin Peninsula, Nunavut; Soper Lake, Nunavut; Tuborg, Lake, Nunavut


Field observations of recent transgression on northern and eastern Melville Island, western Canadian Arctic Archipelago   /   Lajeunesse, P.   Hanson, M.A.
(Geomorphology, v.101, no. 4, 1 Nov. 2008, p. 618-630, ill., maps)
(PCSP/PPCP contribution, no. 015-08)
References.
ASTIS record 73757.
Languages: English
Web: doi:10.1016/j.geomorph.2008.03.002
Libraries: ACU

After ~ 11,000 years of glacio-isostatically induced forced regression, geomorphological evidence indicates that the coastline of eastern Melville Island, western Canadian Arctic Archipelago, is now being transgressed. Recently developed coastal features associated with this transgression include: drowned gullies and small estuaries, barriers and lagoons, barrier islands, erosional notches, backstepping beaches, and drowned tundra vegetation and vehicle tracks dating from the 1970s. We mainly attribute this relative sea-level rise to the eastward migration of a peripheral crustal forebulge. Furthermore, the reported transgression also includes a component from recent eustatic sea-level rise during the 20th century. Recent earthquakes recorded in the Gustav-Lougheed Arch Seismic Zone located in Byam Martin Channel, 70 km east of Melville Island, suggest that neotectonics could also be involved in local relative sea-level adjustments. Other factors associated with global warming, especially the formation of an earlier shore-ice lead coupled with increased storm activity might also be responsible for some of the coastal changes. Our study indicates that the current zero isobase, separating areas of net transgression from those of net regression, is now located off the east coast of the island. Our field observations support recent glacio-isostatic modelling that shows the island is presently undergoing a transgression. (Au)

A, B, G, E, J, F, D
Barrier islands; Beach erosion; Beaches; Climate change; Coast changes; Coasts; Deglaciation; Diapirs; Drainage; Earthquakes; Environmental impacts; Estuaries; Floods; Geomorphology; Gravel; Ice leads; Ice ride-up; Ocean waves; Palaeoclimatology; Permafrost; Plate tectonics; Quaternary period; River deltas; Rivers; Sand; Sea ice; Sea level; Sedimentary rocks; Sediments (Geology); Shore ice; Shorelines; Silt; Snowmelt; Storms; Temporal variations; Thawing; Wetlands

G0813, G0815
Byam Martin Channel, Nunavut; Melville Island, N.W.T./Nunavut; Sabine Peninsula, N.W.T./Nunavut


Abundance and diversity of picocyanobacteria in High Arctic lakes and fjords   /   Van Hove, P.   Vincent, W.F.   Galand, P.E.   Wilmotte, A.
(Algological studies, v.126, no. 1, Apr. 2008, p. 209-227, ill., maps)
(PCSP/PPCP contribution, no. 016-08)
References.
ASTIS record 69297.
Languages: English
Web: http://132.203.57.253/warwickvincent/PDFfiles/239.pdf
Web: doi:10.1127/1864-1318/2008/0126-0209

A series of meromictic lakes, stratified fjords and freshwater lakes at the northern limit of the Canadian High Arctic (northern coastline of Ellesmere Island, Nunavut) were sampled at different depths to quantify the presence of cyanobacteria and to describe their molecular diversity. The sampled ecosystems spanned a wide span of physico-chemical conditions, with conductivities ranging from freshwater (0.2 mS/cm) to seawater (48 mS/cm) and temperatures ranging from -1.91 to 12°C. Fluorescence microscopy cell counts showed that picocyanobacteria occurred in high concentrations (10³ to 2.5 × 10**4 cells/ml) in the oxic and suboxic zones of all of these waters. Molecular analysis of the 16S rRNA gene using Denaturating Gradient Gel Electrophoresis (DGGE) and clone libraries of samples from 8 different lakes and fjords revealed a low diversity of picocyanobacteria affiliated to the genus Synechococcus. In total, 132 short sequences from DGGE bands, clones and strains were obtained. Most of the sequences (83%) clustered in two closely related groups that tend to separate according to saline or freshwater conditions. However, some representatives of each OTU were found in different types of habitat, suggesting some degree of tolerance. These results show that picocyanobacteria are widely distributed under a broad range of physical and chemical conditions in the Arctic environment, and that some genotypes may be specialists that occupy specific habitat types. (Au)

H, F, D, J
Biological sampling; Carbon; Chlorophyll; Cyanophyceae ; Fjords; Fresh-water ecology; Genetics; Iron; Lake ice; Lake stratification; Lakes; Manganese; Marine ecology; Microbial ecology; Ocean temperature; Oligotrophic lakes; Oxygen; Phosphorus; Plant distribution; Plant nutrition; Plant taxonomy; Salinity; Size; Temperature; Water masses; Watersheds

G0813, G03
Char Lake, Nunavut; Disraeli Fiord, Nunavut; Marvin Peninsula, Nunavut; Meretta Lake, Nunavut; Romulus Lake, Nunavut; Taconite Inlet region, Nunavut; Taconite Inlet, Nunavut; Taconite River region, Nunavut; Ward Hunt Ice Shelf, Nunavut


Pollen-based reconstructions of late Holocene climate from the central and western Canadian Arctic   /   Peros, M.C.   Gajewski, K.
(Late Holocene climate and environmental change inferred from Arctic lake sediment / Edited by Darrell Kaufman. Journal of paleolimnology, v. 41, no. 1, Jan. 2009, p. 161-175, ill., maps)
(PCSP/PPCP contribution, no. 017-08)
References.
ASTIS record 66163.
Languages: English
Web: doi:10.1007/s10933-008-9256-9
Libraries: ACU

Two lake-sediment cores from the western and central Canadian Arctic were used to investigate late Holocene climate variability in the region. Both cores were analyzed for pollen, organic matter, biogenic silica, and magnetic susceptibility, and were dated using a combination of 210Pb and 14C techniques. Core MB01, from southwestern Victoria Island, provides a 2600-year-long record. Fossil pollen percentages, along with other parameters, suggest the occurrence of a cold period around 2400 cal year BP (450 BC), followed by slightly warmer conditions by 1800 cal year BP (150 AD), and a return to cooler conditions throughout much of the last millennium. Core SL06, from southern Boothia Peninsula, shows more subtle changes in pollen percentages over its 2500-year duration, but an increase in Cyperaceae and decrease in Oxyria pollen around 1400 cal year BP (550 AD) are indicative of warmer conditions at that time. Quantitative climate reconstructions from these pollen sequences were compared to two other pollen-based climate records from the region and indicate the presence of a widespread wet period ~1500 cal year BP (450 AD), and a cool and dry Little Ice Age. In the reconstructions based on pollen percentage data, the twentieth century summer temperature and annual precipitation in the central and western Canadian Arctic were comparable to that which occurred over the last 2500 years. However, pollen-influx values increase in the most recent sediments, suggesting high plant productivity during the late twentieth century. (Au)

B, E, F, J, H, I
Atmospheric temperature; Bottom sediments; Chironomidae; Climate change; Cores; Databases; Density; Dryas; Effects of climate on plants; Growing season; Instruments; Lakes; Leaves; Measurement; Palaeobotany; Palaeoclimatology; Palaeoecology; Palynology; Plant cover; Plants (Biology); Pollen; Precipitation (Meteorology); Primary production (Biology); Radiocarbon dating; Recent epoch; Sedimentation; Silica; Spectroscopy; Thickness; Tundra ecology; Weather stations

G0812, G0813
Banks Island, N.W.T.; Boothia Peninsula, Nunavut; Ellesmere Island, Nunavut; Prince of Wales Island, Nunavut; Simpson Lake region, Nunavut; Somerset Island, Nunavut; Soper Lake, Nunavut; Victoria Island, N.W.T./Nunavut; Wollaston Peninsula, N.W.T./Nunavut


Cyclic dynamics of sympatric lemming populations on Bylot Island, Nunavut, Canada   /   Gruyer, N.   Gauthier, G.   Berteaux, D.
(Canadian journal of zoology, v. 86, no. 8, Aug. 2008, p. 910-917, ill.)
(PCSP/PPCP contribution, no. 018-08)
References.
ASTIS record 74049.
Languages: English
Web: doi:10.1139/Z08-059
Libraries: ACU

We characterized the fluctuations (amplitude, periodicity) of two sympatric species, the brown lemming (Lemmus sibiricus (Kerr, 1792)) and the northern collared lemming (Dicrostonyx groenlandicus (Traill, 1823)), in a High Arctic area. Our objective was to determine if these populations were cyclic, and if fluctuations in numbers were synchronized between the two species temporally and spatially. An annual index of lemming abundance was obtained using snap-traps at two sites 30 km apart on Bylot Island (Nunavut, Canada) over 13 years (1993-2005) and 9 years (1997-2005), respectively. The time series were analyzed by spectral analyses and autoregressive modelling. At the site with the longest record, brown lemming showed regular population fluctuations of large amplitude (>40-fold), but collared lemming fluctuations were of much smaller amplitude (4-fold). At the other site, the collared lemming population was higher than at the main site, but brown lemmings were still most abundant in the peak year. Models with a second-order function obtained from a spectral analysis were highly correlated with the observed abundance index in both species at the site with the longest time series, and provide evidence of cyclic dynamic. The periods of the cycles were estimated at 3.69 ±0.04 (SE) years for brown lemmings and 3.92 ±0.24 (SE) years for collared lemmings, but the amplitude of the cycle was weak in the latter species. Fluctuations in abundance at the same site were relatively well synchronized between the two species, but the evidence for synchrony between sites was equivocal. (Au)

I, J
Animal distribution; Animal ecology; Animal food; Animal live-capture; Animal population; Lemmings; Mathematical models; Predation; Temporal variations; Wildlife habitat

G0813
Bylot Island, Nunavut


Biolaminated sedimentation in a High Arctic freshwater lake   /   Chutko, K.J.   Lamoureux, S.F.
(Sedimentology, v. 56, no. 6, Oct. 2009, p.1642-1654, ill., maps)
(PCSP/PPCP contribution, no. 019-08)
References.
ASTIS record 74351.
Languages: English
Web: doi:10.1111/j.1365-3091.2009.01049.x
Libraries: ACU

A laminated sequence of lacustrine sediment from an Arctic coastal lake was examined for potential chronological and successional information. The laminae are microbially induced sedimentary structures, the unlithified precursor of stromatolites and are previously unreported in the Arctic. The inferred annual sequence was interpreted to contain a basal clastic unit, overlain with successive cyanobacterial and extracellular polymeric substance units. The complex succession of laminae and inconclusive dating provide a challenge for identifying the chronological nature of the sedimentary structures. Markov chain and time series analyses suggest that a plausible, quasi-annual sequence can be identified to provide a context for palaeoenvironmental reconstruction. Recognition of sedimentary structure in recent biolaminated sediments offers a first step towards the palaeo-environmental evaluation of the geomicrobiological sequence. (Au)

B, H, F, A, J, G
Bathymetry; Bottom sediments; Cesium; Cores; Cyanophyceae; Geochemistry; Geological time; Ice cover; Lake ice; Lakes; Mathematical models; Palaeobotany; Palaeoecology; Precipitation (Meteorology); Radioactive dating; Runoff; Seasonal variations; Sediment transport; Sedimentary structures; Sedimentation; Sediments (Geology); Snowmelt; Stratigraphy; Stream flow; Thickness

G0813
Colin Archer Peninsula, Nunavut


Five thousand years of sediment transfer in a High Arctic watershed recorded in annually laminated sediments from lower Murray Lake, Ellesmere Island, Nunavut, Canada   /   Cook, T.L.   Bradley, R.S.   Stoner, J.S.   Francus, P.
(Late Holocene climate and environmental change inferred from Arctic lake sediment / Edited by Darrell Kaufman. Journal of paleolimnology, v. 41, no. 1, Jan. 2009, p. 77-94, ill., maps)
(PCSP/PPCP contribution, no. 024-08)
References.
ASTIS record 66158.
Languages: English
Web: doi:10.1007/s10933-008-9252-0
Libraries: ACU

Sediments in Lower Murray Lake, northern Ellesmere Island, Nunavut Canada (81°21 N, 69°32 W) contain annual laminations (varves) that provide a record of sediment accumulation through the past 5000+ years. Annual mass accumulation was estimated based on measurements of varve thickness and sediment bulk density. Comparison of Lower Murray Lake mass accumulation with instrumental climate data, long-term records of climatic forcing mechanisms and other regional paleoclimate records suggests that lake sedimentation is positively correlated with regional melt season temperatures driven by radiative forcing. The temperature reconstruction suggests that recent temperatures are ~2.6°C higher than minimum temperatures observed during the Little Ice Age, maximum temperatures during the past 5200 years exceeded modern values by ~0.6°C, and that minimum temperatures observed approximately 2900 varve years BC were ~3.5°C colder than recent conditions. Recent temperatures were the warmest since the fourteenth century, but similar conditions existed intermittently during the period spanning ~4000–1000 varve years ago. A highly stable pattern of sedimentation throughout the period of record supports the use of annual mass accumulation in Lower Murray Lake as a reliable proxy indicator of local climatic conditions in the past. (Au)

B, E, F, J
Atmospheric temperature; Bottom sediments; Climate change; Cores; Density; Ice caps; Instruments; Lakes; Measurement; Melting; Meteorology; Palaeoclimatology; Palaeomagnetism; Precipitation (Meteorology); Radioactive dating; Radionuclides; Recent epoch; Sedimentation; Thickness; Weather stations

G0813
Agassiz Ice Cap, Nunavut; Alert, Nunavut; Eureka, Nunavut; Murray Lake (81 20 N, 69 34 W), Nunavut; Tuborg, Lake, Nunavut


Statistical power : an important consideration in designing community-based monitoring programs for Arctic and sub-Arctic subsistence fisheries   /   VanGerwen-Toyne, M.   Gillis, D.M.   Tallman, R.F.
(Polar biology, v. 37, no. 10, Oct. 2014, p.1435-1444, ill., maps)
(PCSP/PPCP contribution, no. 025-08)
References.
ASTIS record 83183.
Languages: English
Web: doi:10.1007/s00300-014-1533-7
Libraries: ACU

Polar communities and management agencies require well-designed monitoring systems to determine whether harvesting is biologically sustainable. While it is known that life history traits such as length-at-age and fecundity will vary with population density, cost-efficient monitoring requires that these metrics be incorporated into monitoring programs only if their statistical power is high to detect change due to fishing. We present a simple computer-simulated power analysis technique to compare the ability of monitoring designs to detect changes in fish length-at-age and fecundity, after adding effects of exploitation. We developed a methodology for estimating statistical power from first principles using computer simulation techniques which can be applied regardless of the statistical variance pattern in the data. Statistical power increased when more fish were sampled and when larger effects were added. Initially, power increased rapidly by increasing the sample size, regardless of the effect added. However, after 40–50 fish were included in the sample, smaller increments of increased power were obtained; highlighting that a cost-benefit analysis would be necessary. When compared to exploitation experiments in the literature, the stock-specific power analysis used here was able to correctly predict the outcome (significant change observed or not) of the literature studies in most cases. This technique advances the ability of designers of monitoring programs to assess the efficiency of any type of monitoring metric. Further, the simplicity of this power analysis technique allows it to be tailored to different species, life history traits, or potential disturbances to the population. (Au)

I, J, N
Age; Animal growth; Animal mortality; Animal population; Broad whitefish; Effects monitoring; Electronic data processing; Fish management; Fishing; Mathematical models; Size; Subsistence

G0812
Gwich'in Settlement Area, N.W.T.; Peel River, N.W.T./Yukon


Monitoring spawning populations of migratory coregonids in the Peel River, NT : the Peel River Fish Study 1998-2002   /   VanGerwen-Toyne, M.   Walker-Larsen, J.   Tallman, R.F.
Winnipeg, Man. : Central and Arctic Region, Dept. of Fisheries and Oceans, 2008.
vi, 56 p. : ill., maps ; 28 cm.
(Canadian manuscript report of fisheries and aquatic sciences, no. 2851)
(PCSP/PPCP contribution, no. 025-08)
References.
French abstract provided.
Indexed a PDF file from the Web.
ASTIS record 83186.
Languages: English
Web: http://www.grrb.nt.ca/pdf/fisheries/Toyne_Larsen_Tallman%20MR%202851.pdf

The Peel River provides spawning habitat for migratory Inconnu, Arctic Cisco, Broad Whitefish, Lake Whitefish, and Least Cisco. From 1998 to 2002, the Peel River Fish Study collected information on species migration timing, spawning timing, fecundity, sex ratio, fork length, and age. In general, pre-spawning fish were caught migrating up the Peel River from mid-July until river freeze-up; after which spent fish were caught migrating downstream. Species fecundity was highly variable, but all were positively correlated to fork length. In all species, male fish were caught more frequently than female fish. Length-frequency distributions were similar to those reported by previous literature for all species, except Broad Whitefish; which had a greater proportion of larger fish. Age-frequency distributions of all species had a greater range with a higher proportion of older fish than those reported by previous studies. (Au)

I, N, T
Age; Animal live-capture; Animal migration; Animal population; Coregoninae; Fish management; Fish spawning; Seasonal variations; Size; Temporal variations; Wildlife habitat

G0812
Gwich'in Settlement Area, N.W.T.; Peel River, N.W.T./Yukon


A link between water availability and nesting success mediated by predator-prey interactions in the Arctic   /   Lecomte, N.   Gauthier, G.   Giroux, J.-F.
(Ecology, v. 90, no. 2, Feb. 2009, p. 465-475, ill.)
(PCSP/PPCP contribution, no. 026-08)
References.
ASTIS record 74051.
Languages: English
Web: doi:10.1890/08-0215.1
Libraries: ACU

Although water availability is primarily seen as a factor affecting food availability (a bottom-up process), we examined its effect on predator-prey interactions through an influence on prey behavior (a top-down process). We documented a link between water availability, predation risk, and reproductive success in a goose species (Chen caerulescens atlantica) inhabiting an Arctic environment where water is not considered a limited commodity. To reach water sources during incubation recesses, geese nesting in mesic tundra (low water availability) must move almost four times as far from their nest than those nesting in wetlands, which reduced their ability to defend their nest against predators and led to a higher predation rate. Nesting success was improved in high rainfall years due to increased water availability, and more so for geese nesting in the low water availability habitat. Likewise, nesting success was improved in years where the potential for evaporative water loss (measured by the atmospheric water vapor pressure) was low, presumably because females had to leave their nest less often to drink. Females from water-supplemented nests traveled a shorter distance to drink, and their nesting success was enhanced by 20% compared to the control. This shows that water availability and rainfall can have a strong effect on predator-prey dynamics and that changes in precipitation brought by climate change could have an impact on some Arctic species through a top-down effect. (Au)

I, F, J
Animal behaviour; Animal distribution; Animal ecology; Animal food; Animal physiology; Animal reproduction; Arctic foxes; Atmospheric humidity; Biological productivity; Bird nesting; Evaporation; Greater Snow Geese; Predation; Rain; Temporal variations; Tundra ecology; Tundra ponds; Wetlands; Wildlife habitat

G0813
Bylot Island, Nunavut


Arctic epishelf lakes as sentinel ecosystems : past, present and future   /   Veillette, J.   Mueller, D.R.   Antoniades, D.   Vincent, W.F.
(Journal of geophysical research, v.113, no. G4, G04014, Oct. 2008, 11 p., ill., maps)
(PCSP/PPCP contribution, no. 028-08)
References.
ASTIS record 65478.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/243.pdf
Web: doi:10.1029/2008JG000730
Libraries: ACU

Ice shelves are a prominent but diminishing feature of the northern coastline of Ellesmere Island in the Canadian High Arctic (latitude 82-83°N). By blocking embayments and fiords, this thick coastal ice can create epishelf lakes, which are characterized by a perennially ice-capped water column of freshwater overlying seawater. The goal of this study was to synthesize new, archived, and published data on Arctic epishelf lakes in the context of climate change. Long-term changes along this coastline were evaluated using historical reports, cartographic analysis, RADARSAT imagery, and field measurements. These data, including salinity-temperature profiling records from Disraeli Fiord spanning 54 years, show the rapid decline and near disappearance of this lake type in the Arctic. Salinity-temperature profiling of Milne Fiord, currently blocked by the Milne Ice Shelf, confirmed that it contained an epishelf lake composed of a 16-m thick freshwater layer overlying seawater. A profiling survey along the coast showed that there was a continuum of ice-dammed lakes from shallow systems dammed by multiyear landfast sea ice to deep epishelf lakes behind ice shelves. The climate warming recently observed in this region likely contributed to the decline of epishelf lakes over the last century, and the air temperature trend predicted for the Arctic over the next several decades implies the imminent loss of this ecosystem type. Our results underscore the distinctive properties of coastal ice-dammed lakes and their value as sentinel ecosystems for the monitoring of regional and global climate change. (Au)

F, G, D, E, J
Aerial photography; Atmospheric temperature; Climate change; Coast changes; Environmental impacts; Fast ice; Ice shelves; Lake stratification; Lakes; Melting; Ocean currents; Ocean temperature; Runoff; Salinity; SAR; Satellite photography; Sea ice; Sea water; Temperature; Temporal variations; Thickness; Tides; Water masses

G03, G0813
Ayles Fiord, Nunavut; Disraeli Fiord, Nunavut; Ellesmere Island, Nunavut; Kulutingwak Fiord, Nunavut; M'Clintock Inlet, Nunavut; Markham Fiord, Nunavut; Milne Fiord, Nunavut; Milne Glacier, Nunavut; Milne Ice Shelf, Nunavut; Moss Bay, Nunavut; Nansen Sound region, Nunavut; Phillips Inlet, Nunavut; Serson Ice Shelf, Nunavut; Taconite Inlet, Nunavut; Ward Hunt Ice Shelf, Nunavut


Trace element and metallothionein concentrations in seabirds from the Canadian Arctic   /   Braune, B.M.   Scheuhammer, A.M.
(Environmental toxicology and chemistry, v. 27, no. 3, Mar. 2008, p. 645-651, ill., maps)
(PCSP/PPCP contribution, no. 033-08)
References.
ASTIS record 65075.
Languages: English
Web: doi:10.1897/07-269.1
Libraries: ACU

Livers and kidneys were collected for five seabird species from the Canadian Arctic during the 1983 and 1991 to 1993 breeding seasons. Livers were analyzed for Cd, Hg, Pb, and Se, and kidneys were analyzed for Cd, Cu, Zn, and metallothionein (MT). Concentrations of the essential elements, Cu and Zn, were in agreement with those previously published in the literature. Thick-billed murres (Uria lomvia) from Ivujivik on the Hudson Strait/Hudson Bay coast in northwestern Quebec (Canada) had the highest mean renal concentrations of Cu, Zn, and Cd. Among the four species collected from Prince Leopold Island, northern fulmars (Fulmarus glacialis) had the highest hepatic concentrations of both Cd and Hg. The highest Se concentrations were found in northern fulmars and black-legged kittiwakes (Rissa tridactyla) from Prince Leopold Island. Hepatic Pb concentrations were low (<0.3 µg/g dry wt) in all species at all locations. Metallothionein concentrations were positively correlated with Cd and Zn for all species combined but were not correlated with Cu in any species. No significant relationships were found between MT and Cu or Zn in black guillemots (Cepphus grylle) or glaucous gulls (Larus hyperboreus). To our knowledge, this is the first report of MT concentrations and their relationships with trace metals in Arctic seabirds. (Au)

I
Biological sampling; Black Guillemots; Cadmium; Copper; Fulmars; Glaucous Gulls; Internal organs; Kittiwakes; Lead; Mercury; Metals; Necropsy; Proteins; Sea birds; Selenium; Spectroscopy; Thick-billed Murres; Toxicity; Trace elements; Zinc

G0813, G0826
Akpatok Island, Nunavut; Coats Island, Nunavut; Nuvuk Islands, Nunavut; Prince Leopold Island Migratory Bird Sanctuary, Nunavut; Salluit region, Québec


Estimation of grain size variability with micro X-ray fluorescence in laminated lacustrine sediments, Cape Bounty, Canadian High Arctic   /   Cuven, S.   Francus, P.   Lamoureux, S.F.
(Journal of paleolimnology, v. 44, no. 3, Oct. 2010, p. 803-817, ill., maps)
(PCSP/PPCP contribution, no. 034-08)
References.
The online version of this article contains supplementary material which is available to authorized users.
ASTIS record 71856.
Languages: English
Web: doi:10.1007/s10933-010-9453-1
Libraries: ACU

Finely laminated sediment cores from two Arctic lakes were investigated using the ItraxTM Core Scanner that provides micro X-ray fluorescence (µ-XRF) measurements with a spatial resolution of 100 µm. We compared these chemical measurements with standard geochemical methods using, at the macroscopic scale, inductively coupled plasma-atomic emission spectrometry (ICP-AES) and, at the microscopic scale, energy dispersive spectroscopy (EDS). We also investigated the relationship between the chemical profiles and the grain size of sediments at macro-scale using laser particle-size analysis, and at microscopic scale, using thin section image analysis techniques. Results show a link between grain size and the relative abundance of several elements. Silicon and zirconium are associated with very coarse silt and sand deposits, K and Fe with clay-rich layers, and Ti with silty facies. Four sedimentary facies are characterised based on sedimentary structure and texture, and interpreted in terms of known seasonal hydroclimatic processes. We show that it is possible to identify these sedimentary facies using µ-XRF element abundance or ratio variations. The K/Ti ratio is the best marker of the upper varve boundary, and it might be used for varve identification and counting of Cape Bounty sediments in future. More generally, this study demonstrates new applications for paleohydrological reconstructions from laminated sediments. (Au)

B, E, F, A
Bottom sediments; Chemical properties; Clay; Climate change; Cores; Fluorometry; Geochemistry; Ice cover; Lakes; Lasers; Measurement; Minerals; Nivation; Palaeoclimatology; Palaeogeography; Physical properties; Precipitation (Meteorology); Runoff; Sand; Seasonal variations; Sediment transport; Sedimentation; Sediments (Geology); Silicon; Silt; Snowmelt; Soil texture; Spectroscopy; Surface properties; Thickness; X-rays; Zircon

G0813
Bounty, Cape, region, Nunavut


Hydrological and sediment yield response to summer rainfall in a small High Arctic watershed   /   Dugan, H.A.   Lamoureux, S.F.   Lafrenière, M.J.   Lewis, T.
(Hydrological processes, v. 23, no. 10, 15 May 2009, p.1514-1526, ill., map)
(PCSP/PPCP contribution, no. 036-08)
References.
ASTIS record 68608.
Languages: English
Web: doi:10.1002/hyp.7285
Libraries: ACU

In cold regions, the response and related antecedent mechanisms that produce flood flows from rainfall events have received limited study. In 2007, a small watershed at Cape Bounty, Melville Island, Nunavut, was studied in detail during the melt season. Two rainfall events on June 30 and July 22, totalling 9.2 and 10.8 mm, respectively, represented significant contributions to seasonal discharge and sediment transport in a year with a low winter snowpack. The precipitation events elevated discharge and suspended sediment concentrations to twice the magnitude of the nival melt, and generated the only measurable downstream lacustrine turbidity current of the season. In two days, rainfall runoff transported 35% of the seasonal suspended sediment load, in contrast to 29% transported over the nival freshet. The magnitude and intensity of the rain events were not unusual in this setting, but the rainfall response was substantial in comparison with equivalent past events. Exceptional temperatures of July 2007 generated early, deep permafrost thaw, and ground ice melt. The resultant increase in soil moisture amplified the subsequent rainfall runoff and sediment transport response. These results demonstrate the importance of antecedent moisture conditions and the role of permafrost active layer development as an important factor in the rainfall runoff and sediment transport response to precipitation events. (Au)

F, E, J, C
Active layer; Atmospheric temperature; Floods; Ground ice; Hydrology; Meteorology; Permafrost; Polar deserts; Rain; River discharges; Runoff; Seasonal variations; Sediment transport; Snow; Snow hydrology; Snow surveys; Snowmelt; Soil moisture; Soil temperature; Suspended solids; Temporal variations; Thawing; Watersheds

G0813
Bounty, Cape, region, Nunavut


Assessment of a time-integrated fluvial suspended sediment sampler in a High Arctic setting   /   McDonald, D.M.   Lamoureux, S.F.   Warburton, J.
(Special issue : sedimentary fluxes and budgets in changing cold environments : quantitative analysis and scaling issues. Geografiska annaler. Series A, Physical geography, v. 92A, no. 2, June 2010, p. 225-235, ill., maps)
(PCSP/PPCP contribution, no. 039-08)
References.
ASTIS record 71847.
Languages: English
Web: doi:10.1111/j.1468-0459.2010.00391.x
Libraries: ACU

Two versions of a fluvial sediment trap designed to collect integrated samples of ambient suspended sediment load were deployed in a small river at Cape Bounty, Melville Island, Nunavut in the Canadian High Arctic. Daily and bi-daily sediment capture in the traps was broadly proportionate with suspended loads estimated directly from daily sediment flux measurements but showed highly variable trap capture rates. Grain size analysis showed that the median grain size (D50) of the captured material was significantly coarser than the ambient material, although the D50 of the two trap versions deployed was not significantly different. These results suggest that the traps did not consistently collect a representative mass or particle size sample in a river environment with highly variable conditions. This is explained by consideration of the hydraulic design of the traps and a highly dynamic stream environment. Hence, deployment of fluvial traps in small ephemeral Arctic rivers will require further testing and refinement of the hydraulic design. (Au)

C, F, E, A
Bottom sediments; Climate change; Coast changes; Coasts; Design and construction; Effects of climate on permafrost; Equipment and supplies; Erosion; Floods; Hydrology; Meteorology; Permafrost; River discharges; Sediment transport; Sedimentation; Snow hydrology; Snowmelt; Soil texture; Stream flow; Suspended solids; Temporal variations; Thawing; Thermal regimes; Watersheds

G0813
Bounty, Cape, region, Nunavut


Biogeography of freshwater ostracodes in the Canadian Arctic Archipelago   /   Bunbury, J.   Gajewski, K.
(Arctic, v. 62, no. 3, Sept. 2009, p. 324-332, ill., maps)
(PCSP/PPCP contribution, no. 046-08)
References.
ASTIS record 68346.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic62-3-324.pdf
Web: doi:10.14430/arctic153
Libraries: ACU

Seven species of freshwater ostracodes were identified from the sediments of 43 lakes on eight islands across the Canadian Arctic Archipelago. No ostracodes were encountered in the sediments of almost half of the lakes, and most were found at sites that had higher alkalinity. Several taxa endemic to Arctic regions are found across the Arctic Archipelago, including Candona rectangulata Alm, Limnocythere liporeticulata Delorme, and Tonnacypris glacialis Sars. The distributions of Cytherissa lacustris Sars, Cyclocypris globosa Sars, Limnocythere sappaensis Staplin, and Limnocythere (Limnocytherina) camera Delorme are more limited; this fact is attributed to differences in ion composition and concentrations. (Au)

B, I, F, J, E
Animal distribution; Bottom sediments; Chemical properties; Climatology; Cores; Fresh-water ecology; Geology; Hydrology; Lakes; Ostracoda; Palaeoclimatology; Palaeoecology; Palaeohydrology; Palaeontology

G0813, G0812
Axel Heiberg Island, Nunavut; Bathurst Island, Nunavut; Canadian Arctic Islands; Devon Island, Nunavut; Ellesmere Island, Nunavut; Melville Island, N.W.T./Nunavut; Prince of Wales Island, Nunavut; Somerset Island, Nunavut; Victoria Island, N.W.T./Nunavut


Biogeographic distributions and environmental controls of stream diatoms in the Canadian Arctic Archipelago   /   Antoniades, D.   Douglas, M.S.V.   Smol, J.P.
(Botany, v. 87, no. 5, May 2009, p. 443-454, ill., map)
(PCSP/PPCP contribution, no. 051-08)
Appendix.
References.
ASTIS record 74047.
Languages: English
Web: doi:10.1139/B09-001
Libraries: ACU

Streams are amongst the most sensitive ecosystems in Arctic regions to environmental change. Although diatoms are excellent indicators of environmental change, little information is available about stream diatom distributions across the vast Canadian High Arctic. We sampled 42 streams from nine islands in the Canadian Arctic Archipelago to study their diatom floras and evaluate the influences of biogeography and environmental variables on species distributions. Highly divergent diatom communities were identified, with 100% species overturn between the most dissimilar communities. Taxa including Hannaea arcus (Ehrenberg) Patrick were characteristic of streams from all regions; other common taxa included Nitzschia perminuta (Grunow) Peragallo, Rossithidium petersenii (Hustedt) Round & Bukhtiyarova, Achnanthidium minutissimum (Kutzing) Czarnecki, and Eucocconeis laevis (Ostrup) H. Lange-Bertalot. Canonical correspondence analysis indicated that diatom assemblages were significantly related to differences in pH, temperature, latitude, and longitude, which together explained 14.7% of species variability. Analysis of similarities indicated that communities did not differ significantly between epilithic and epiphytic samples and that there were weak but significant differences between the diatom communities in our three regions. These data provide important baseline information for future biomonitoring efforts as well as for paleolimnological studies of past stream hydrology. (Au)

H, F, E, J
Atmospheric temperature; Classification; Diatoms; Electrical properties; Fresh-water ecology; Identification; Plant distribution; Plant taxonomy; Precipitation (Meteorology); Rivers; Stream flow; Temperature; Water pH

G0812, G0813
Alert region, Nunavut; Axel Heiberg Island, Nunavut; Banks Island, N.W.T.; Cornwallis Island, Nunavut; Ellef Ringnes Island, Nunavut; Eureka region, Nunavut; Herschel, Cape, region, Nunavut; Melville Island, N.W.T./Nunavut; Pim Island, Nunavut; Prince Patrick Island, N.W.T.; Victoria Island, N.W.T./Nunavut


Surviving on cached foods - the energetics of egg-caching by arctic foxes   /   Careau, V.   Giroux, J.-F.   Gauthier, G.   Berteaux, D.
(Canadian journal of zoology, v. 86, no. 10, Oct. 2008, p.1217-1223, ill.)
(PCSP/PPCP contribution, no. 052-08)
References.
ASTIS record 74050.
Languages: English
Web: doi:10.1139/Z08-102
Libraries: ACU

Food-caching by arctic foxes (Vulpes lagopus (L., 1758)) is a behavioural adaptation thought to increase winter survival, especially in bird colonies where a large number of eggs can be cached during a short nesting season. In this paper, we measured the energy content of greater snow goose (Chen caerulescens atlantica Kennard, 1927) eggs and evaluated their perishability when cached in tundra soil for a whole summer. We estimated that eggs lost only ~8% of their dry mass over 60 days of storage in the ground. We used published estimates on digestibility of nutrients by arctic foxes to estimate that fresh and stored goose eggs contained 816 and 730 kJ of metabolizable energy, respectively, a difference of 11%. Using information on arctic fox energetics, we evaluated that 145 stored eggs were required to sustain the growth of one pup from the age of 1 to 3 months (nutritional independence). Moreover, 23 stored eggs were energetically equivalent to the average fat deposit of an arctic fox during winter. Finally, we calculated that an adult arctic fox would need to recover 160-220 stored eggs to survive 6 months in resting conditions during cold winter temperatures. This value increased to 480 when considering activity cost. Based on egg acquisition and caching rates observed in many goose colonies, we conclude that cached eggs represent an important source of energy relative to the needs of an arctic fox during winter, and have thus a high fitness value. (Au)

I, J, C
Animal behaviour; Animal ecology; Animal food; Animal growth; Animal physiology; Animal reproduction; Arctic foxes; Bird nesting; Density; Energy budgets; Fats; Greater Snow Geese; Mathematical models; Metabolism; Predation; Proteins; Seasonal variations; Soil temperature; Survival

G0813
Bylot Island, Nunavut


Redefining walrus stocks in Canada   /   Stewart, R.E.A.
(Arctic, v. 61, no. 3, Sept. 2008, p. 292-308, ill., maps)
(PCSP/PPCP contribution, no. 054-08)
References.
Abstract in English and French.
ASTIS record 64911.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic61-3-292.pdf
Web: doi:10.14430/arctic26
Libraries: ACU

Defining management units is basic to the sound management of resources. Walrus (Odobenus rosmarus rosmarus) are hunted throughout their range in Canada and are subject to other human activities requiring management decisions. Current management units are based on a comprehensive review and a stock assessment completed in the mid 1990s. Between 1993 and 2004, satellite-linked radio tags provided information on the movements of walrus in Canada's High Arctic. These data were incorporated with other information that has become available since 1995 to reassess walrus management units in Canada. Tagging data and other information suggest that some finer discrimination of walrus populations is needed as a precautionary approach and to formulate testable hypotheses. Specifically, the previous North Water/Baffin Bay walrus stock may be considered to be three stocks: Baffin Bay, west Jones Sound, and Penny Strait-Lancaster Sound stocks. The Foxe Basin population appears to comprise two stocks (North Foxe Basin and Central Foxe Basin) rather than one. Previously suspected subdivisions in the Hudson Bay-Davis Strait population are substantiated by isotopic evidence although sampling on a finer geographic scale is required before this stock can be partitioned. There is new evidence to support the previously postulated separation of the walrus in the Southern and Eastern Hudson Bay stock from all others, but no evidence to warrant subdivision. (Au)

I, J, N, D, G, T
Animal behaviour; Animal diseases; Animal distribution; Animal live-capture; Animal mortality; Animal population; Animal tagging; Biological sampling; Evolution (Biology); Food; Gender differences; Genetics; Hunting; Inuit; Isotopes; Lead; Marine pollution; Organochlorines; Polynyas; Radio tracking of animals; Satellite communications; Sea ice; Seasonal variations; Subsistence; Telemetry; Temporal variations; Trace elements; Walruses; Wildlife management

G0815, G0814, G09, G0826, G0813, G10
Baffin Bay-Davis Strait; Baffin Island waters, Nunavut; Canadian Arctic Islands waters; Foxe Basin, Nunavut; Hudson Bay; Hudson Strait, Nunavut/Québec; Jones Sound, Nunavut; Labrador waters; Lancaster Sound, Nunavut; North Water Polynya, Baffin Bay; Nunavik, Québec; Nunavut; Penny Strait, Nunavut; Sisimiut, Greenland; Ungava, Baie d', Québec


Fungal endorhizal associates of Equisetum species from western and Arctic Canada   /   Hodson, E.   Shahid, F.   Basinger, J.   Kaminskyj, S.
(Mycological progress, v. 8, no. 1, 2009, p. 19-27, ill., map)
(PCSP/PPCP contribution, no. 055-08)
References.
ASTIS record 75900.
Languages: English
Web: doi:10.1007/s11557-008-0574-0
Libraries: ACU

We describe endorhizal fungi associated with Equisetum species collected from Ellesmere Island (82°N), Axel Heiberg Island (80°N), and from sites in Yukon Territory and the Prairie Provinces (51-67°N). Fungal colonization was assessed using a multiple quantitation microintersect method for lactofuchsin-stained roots examined with wide-field and confocal epifluorescence microscopy. Equisetum roots host abundant and diverse endorhizal fungal associates. For 85 specimens from 14 sites, total colonization averaged 30±3%, range 0-97%. Colonization rates for wide aseptate hyphae characteristic of arbuscular mycorrhizae (5±1%) was significantly less than for fine endophytes (20±3%) or septate endophytes (17±2%). Equisetum spp. are abundant in tundra and an important understory plant in boreal forests, where they are particularly common on burned or disturbed sites. Endorhizal fungi associated with Equisetum may have broad ecological relevance. (Au)

H, J, C
Equisetum; Fluorometry; Fungi; Microscopes; Mycorhizal fungi; Plant collections; Plant distribution; Plant growth; Revegetation; Soil microorganisms; Taiga ecology; Temporal variations; Tundra ecology

G0813, G0811, G0821, G0822, G0823, G0812
Alberta; Axel Heiberg Island, Nunavut; British Columbia; Ellesmere Island, Nunavut; Inuvik region, N.W.T.; Saskatchewan; Yukon


Permafrost and climate change at Herschel Island (Qikiqtaruq), Yukon Territory, Canada   /   Burn, C.R.   Zhang, Y.
(Journal of geophysical research, v.114, F02001, 2009, 17 p., ill., maps)
(PCSP/PPCP contribution, no. 056-08)
References.
ASTIS record 68603.
Languages: English
Web: doi:10.1029/2008JF001087

Herschel Island, in the southern Beaufort Sea, is dominantly a glacier ice thrust feature composed of ice-rich, perennially frozen sediments. Climate data are available for Herschel Island from 1899 to 1905 and 1995-2006. Air temperatures at Herschel Island are similar to sites on the adjacent mainland. Late winter snow depth is only about 20 cm, or half the depth on the mainland, and local topography defines the sites of annually recurring snowdrifts. Near-surface ground temperatures, thaw depths, and ground ice contents have been investigated over a 750m transect leading up Collinson Head, the easternmost part of the island. The ground temperature profile to 42m depth indicates recent warming of permafrost because the temperature decreases with depth. The temperature at 15m depth is -8.0°C, the same as the annual mean temperature at 1m depth at windswept sites along the transect. A simulation of the ground thermal regime, calibrated with local ground properties, equilibrated with the climate of 1899-1905, and driven by the climate of the region during the 20th century reproduces the present ground temperature profile and the annual temperature cycle for 1m depth at windswept sites. The model indicates that the mean annual temperatures at the top of permafrost and at 20m depth have increased by 2.6 and 1.9°C, respectively, since 1899-1905, and the perturbation in ground temperature has reached about 120m depth. Active layer thickness measured in the terrain types studied on Herschel Island is about 55 cm, 15 to 25 cm greater than field data from these units collected in 1985. (Au)

C, E, J, V, F, H
Active layer; Atmospheric temperature; Boreholes; Climate change; Effects of climate on permafrost; Ground ice; Mass wasting; Mathematical models; Permafrost; Plant distribution; River discharges; Snow cover; Soil temperature; Spatial distribution; Subsidence; Surface temperature; Temporal variations; Thawing; Thermal regimes

G0811
Collinson Head, Yukon; Herschel Island, Yukon; Komakuk Beach, Yukon; Mackenzie Delta, Yukon; Mackenzie River, N.W.T.; Shingle Point, Yukon


After whom is Herschel Island named?   /   Burn, C.R.
(Arctic, v. 62, no. 3, Sept. 2009, p. 317-323, maps, ports.)
(PCSP/PPCP contribution, no. 057-08)
References.
ASTIS record 68345.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic62-3-317.pdf
Web: doi:10.14430/arctic152
Libraries: ACU

Herschel Island (Qikiqtaruk) is a seasonally inhabited island off the western Arctic coast of Canada. It was designated as a Yukon territorial park under the Inuvialuit Final Agreement (1987) in recognition of its physical and cultural significance. The island was named by Captain John Franklin of the Royal Navy on 15 July 1826, during his second voyage of Arctic exploration. Unlike entries for other features named by Franklin along this coast, the journal record of this event does not indicate the specific person after whom he named the island. Franklin's journal and his published account state only that he wished to honour the name Herschel, borne most prominently by Sir William Herschel, who discovered the planet Uranus, Sir William's sister Caroline Herschel, who discovered eight comets, and Sir William's son Sir John Herschel, the brilliant polymath; in other words, he wished to honour this preeminent late Georgian scientific family. (Au)

V, Y, A
Astronomy; Exploration; Franklin, Sir John, 1786-1847; Geographical names; History; Natural history; Science

G0811
Herschel Island, Yukon


Estimating the extent of near-surface permafrost using remote sensing, Mackenzie Delta, Northwest Territories   /   Nguyen, T.-N.   Burn, C.R.   King, D.J.   Smith, S.L.
(Special issue : permafrost in the Mackenzie Delta, Canada. Permafrost and periglacial processes, v. 20, no. 2, Apr./June 2009, p. 141-153, ill., map)
(PCSP/PPCP contribution, no. 058-08)
References.
This paper is a contribution from the Environmental Studies Across Treeline project, ESS contribution no. 20080003.
The PCSP/PPCP contribution number is incorrectly given as 058-05 in the Acknowledgments of this article. The correct number is 058-08.
ASTIS record 68583.
Languages: English
Web: doi:10.1002/ppp.637
Libraries: ACU

The extent of near-surface permafrost, or perennially frozen ground within 3 m of the surface, was estimated for the Mackenzie River delta by determining its association with riparian vegetation communities in the field, and by subsequently mapping these vegetation communities using SPOT-5 data and the supervised maximum-likelihood classification technique. Near-surface permafrost was absent beneath willow-horsetail (Salix-Equisetum) vegetation communities on point bars and alluvial islands throughout the delta and beneath horsetail (Equisetum) communities in the southern and central delta. Near-surface permafrost was found beneath all other vegetation communities and land surface types. Multispectral SPOT-5 data were classified with overall accuracies greater than 80 per cent. Using the remotely sensed vegetation community data, near-surface permafrost was estimated to occur beneath 93 per cent, 95 per cent and 96 per cent of the land surface within the investigation areas of the southern, central and northern delta, respectively. In contrast to the most recent Permafrost Map of Canada, these results indicate that the Mackenzie Delta is part of the continuous permafrost zone. (Au)

C, H, A, F
Active layer; Alders; Drilling; Equisetum; Floods; Islands; Land classification; Mapping; Mathematical models; Measurement; Permafrost; Permafrost surveys; Plant distribution; Plant succession; Plant-soil relationships; Plant-water relationships; Remote sensing; Rivers; Satellite photography; Sedges; Snowdrifts; Soil temperature; Spatial distribution; Spruces; Taiga ecology; Thermal regimes; Thickness; Treeline; Willows

G0812
Mackenzie Delta, N.W.T.


Vertical structure of archaeal communities and the distribution of ammonia monooxygenase A gene variants in two meromictic High Arctic lakes   /   Pouliot, J.   Galand, P.E.   Lovejoy, C.   Vincent, W.F.
(Polar microbiology / Edited by C. Cary, A. Murray, and I. McDonald. Environmental microbiology, v. 11, no. 3, Mar. 2009, p. 687-699, ill., maps)
(PCSP/PPCP contribution, no. 059-08)
References.
ASTIS record 70385.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/245.pdf
Web: doi:10.1111/j.1462-2920.2008.01846.x
Libraries: ACU

The distribution of archaeal amoA and 16S rRNA genes was evaluated in two marine-derived, meromictic lakes in the Canadian High Arctic: Lake A and Lake C1 on the northern coast of Ellesmere Island. The amoA gene was recorded in both lakes, with highest copy numbers in the oxycline. Sequence analysis showed that amoA from the two lakes shared 94% similarity, indicating at least two phylogenetically distinct clusters. Clone libraries of archaeal 16S rRNA genes from Lake A revealed strong vertical differences in archaeal community diversity and composition down the water column. The oxic layer was dominated by one group of Euryarchaeota affiliated to the Lake Dagow Sediment (LDS) cluster. This group was absent from the oxycline, which had an extremely low archaeal diversity of two phylotypes. Both belonged to the Crenarchaeota Marine Group I (MGI), the marine group that has been linked to archaeal amoA; however, there was a low ratio of amoA to MGI copy numbers, suggesting that many MGI Archaea did not carry the amoA gene. The anoxic zone contained representatives of the RC-V (Rice Cluster-V) and LDS clusters of Euryarchaeota. These results show the strong vertical differentiation of archaeal communities in polar meromictic lakes, and they suggest archaeal nitrification within the oxycline of these highly stratified waters. (Au)

H, I, F, J
Animal distribution; Archaea; Bacteria; Biological sampling; Carbon; Chlorophyll; Enzymes; Fresh-water ecology; Genetics; Lake stratification; Lakes; Microbial ecology; Nitrogen; Nitrogen cycling; Nitrogen oxides; Oxygen; Phosphorus; Plant distribution; Salinity; Temperature; Water pH

G0813
Marvin Peninsula, Nunavut; Taconite Inlet region, Nunavut


Tug of war between continental gene flow and rearing site philopatry in a migratory bird : the sex-biased dispersal paradigm reconsidered   /   Lecomte, N.   Gauthier, G.   Giroux, J.-F.
(Molecular ecology, v. 18, no. 4, Feb. 2009, p. 593-602, ill., maps)
(PCSP/PPCP contribution, no. 060-08)
References.
ASTIS record 74342.
Languages: English
Web: doi:10.1111/j.1365-294X.2008.04067.x
Libraries: ACU

Nonrandom dispersal has been recently advanced as a mechanism promoting fine-scale genetic differentiation in resident populations, yet how this applies to species with high rates of dispersal is still unclear. Using a migratory species considered a classical example of male-biased dispersal (the greater snow goose, Chen caerulescens atlantica), we documented a temporally stable fine-scale genetic clustering between spatially distinct rearing sites (5-30 km apart), where family aggregates shortly after hatching. Such genetic differentiation can only arise if, in both sexes, dispersal is restricted and nonrandom, a surprising result considering that pairing occurs among mixed flocks of birds more than 3000 km away from the breeding grounds. Fine-scale genetic structure may thus occur even in migratory species with high gene flow. We further show that looking for genetic structure based on nesting sites only may be misleading. Genetically distinct individuals that segregated into different rearing sites were in fact spatially mixed during nesting. These findings provide new, scale-dependent links between genetic structure, pairing, and dispersal and show the importance of sampling different stages of the breeding cycle in order to detect a spatial genetic structure. (Au)

I, J
Animal behaviour; Animal distribution; Animal ecology; Animal migration; Animal population; Biological sampling; Bird nesting; Blood; Evolution (Biology); Gender differences; Genetics; Greater Snow Geese; Mathematical models; Snowy Owls; Tundra ecology

G0813
Bylot Island, Nunavut


Sedimentology of perennial ice-covered, meromictic Lake A, Ellesmere Island, at the northern extreme of Canada   /   Tomkins, J.D.   Lamoureux, S.F.   Antoniades, D.   Vincent, W.F.
(Canadian journal of earth sciences, v. 46, no. 2, Feb. 2009, p. 83-100, ill., maps)
(PCSP/PPCP contribution, no. 001-09)
References.
ASTIS record 68468.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/251.pdf
Web: doi:10.1139/E09-008
Libraries: ACU

The sedimentology of coastal, meromictic Lake A, Ellesmere Island (83°00'N, 75°30'W), was investigated to understand the linkages between the extreme lake environment and its sedimentary features. Four facies were identified within the sedimentary record that represent stages of the lake's development from a marine embayment to a meromictic lake. Despite low ecosystem productivity, both clastic and biogenic materials contribute substantially, and highly seasonal sedimentation, pervasive ice cover, and anoxia in the saline bottom water (monimolimnion) act to preserve annual sedimentary units (varves) within the upper part of the sedimentary record. Sediment texture is predominantly silt and clay, but the irregular presence of sand indicates past episodes of higher energy stream discharge to the lake. Oxygen incursions into the chemocline likely cause bacteria mortality and provide elemental sulphur for iron sulphides that are deposited in the sediments. Millimetre-scale sedimentary pellets are also a conspicuous feature in the sediments and are interpreted to result from littoral sediment transport by ice-rafting. Many of Lake A's notable sedimentary features are also evident in other High Arctic meromictic lakes, particularly those on the northern coast of Ellesmere Island. These similarities and the important biogenic component identified in Lake A suggest that processes in these sedimentary environments are more complex than previously thought. (Au)

B, E, F, J, I, G, H
Bacteria; Bathymetry; Bottom sediments; Carbon; Clay; Climate change; Coast changes; Cores; Crystals; Cyanophyceae; Electrical properties; Foraminifera; Formation; Ice cover; Instruments; Iron; Lake ice; Lake stratification; Lakes; Measurement; Melting; Meteorology; Microbial ecology; Nitrogen; Palaeoclimatology; Palaeoecology; Photosynthesis; Pyrite; Radioactive dating; Radiocarbon dating; Radionuclides; Recent epoch; River discharges; Runoff; Sand; Seasonal variations; Sediment transport; Sedimentary structures; Sedimentation; Sediments (Geology); Silt; Snowmelt; Spectroscopy; Sulphur; Temperature; Temporal variations; Thickness; Water pH

G0813
Alert, Nunavut; Marvin Peninsula, Nunavut; Quttinirpaaq National Park, Nunavut; Ward Hunt Ice Shelf, Nunavut


Has early ice clearance increased predation on breeding birds by polar bears?   /   Smith, P.A.   Elliott, K.H.   Gaston, A.J.   Gilchrist, H.G.
(Polar biology, v. 33, no. 8, Aug. 2010, p.1149-1153, ill., maps)
(PCSP/PPCP contribution, no. 003-09)
References.
ASTIS record 74777.
Languages: English
Web: doi:10.1007/s00300-010-0791-2
Libraries: ACU

Past studies suggest that polar bears (Ursus maritimus) consume terrestrial food only opportunistically and derive little nutritional benefit from it. Here, we present observations of at least 6 bears consuming large numbers of snow goose (Chen caerulescens) eggs at two locations in the eastern low Arctic in 2004 and 2006. We also report two records of a polar bear eating the eggs and chicks of cliff-nesting thick-billed murres (Uria lomvia) in 2000 and 2003. Climatic warming has resulted in progressively earlier ice break-up in Hudson Bay, forcing bears ashore much earlier than historical records indicate. Advancement in the nesting dates of birds has been more modest, and this mismatch in timing could lead to an increasing overlap between the nesting period of birds and the period during which bears are on land. At these sites in these years, bears were on land prior to the hatch of nests, and the predation that ensued was catastrophic for the birds at a local scale. Although anecdotal, our observations highlight the complexity of trophic interactions that may occur in a changing Arctic. (Au)

I, E, G, J
Adaptability (Psychology); Animal behaviour; Animal distribution; Animal food; Animal mortality; Animal population; Bird nesting; Breakup; Climate change; Melting; Polar bears; Predation; Sea ice; Sea ice ecology; Snow Geese; Survival; Temporal variations; Thick-billed Murres; Trophic levels

G0813, G0814
Coats Island waters, Nunavut; Coats Island, Nunavut; Southampton Island waters, Nunavut; Southampton Island, Nunavut


Inter-annual variation in the breeding chronology of Arctic shorebirds : effects of weather, snow melt and predators   /   Smith, P.A.   Gilchrist, H.G.   Forbes, M.R.   Martin, J.-L.   Allard, K.
(Journal of avian biology, v. 41, no. 3, May 2010, p. 292-304, ill., map)
(PCSP/PPCP contribution, no. 004-09)
References.
ASTIS record 74369.
Languages: English
Web: doi:10.1111/j.1600-048X.2009.04815.x
Libraries: ACU

Arctic breeding shorebirds travel thousands of kilometres between their wintering and breeding grounds, yet the period over which they arrive and begin to initiate nests spans only several weeks. We investigated the role of local conditions such as weather, snow cover and predator abundance on the timing of arrival and breeding for shorebirds at four sites in the eastern Canadian arctic. Over 11 years, we monitored the arrival of 12 species and found 821 nests. Weather was highly variable over the course of this study, and the date of 50% snow cover varied by up to three weeks between years. In contrast, timing of arrival varied by one week or less at our sites, and was not well predicted by local conditions such as temperature, wind or snow melt. Timing of breeding was related to the date of 50% snow melt, with later snow melt resulting in delayed breeding. Higher predator abundance resulted in earlier nesting than would be predicted by snow cover alone. We hypothesise that when predation risk is high, the value of potential re-nesting exceeds the energetic risks of early breeding. Synchrony of breeding was significantly higher in late breeding years suggesting a relatively fixed date for the termination of nest initiation, after which nesting is no longer profitable. (Au)

I, E, F, J
Animal food; Animal migration; Animal mortality; Arctic foxes; Atmospheric temperature; Bird nesting; Effects monitoring; Jaegers; Lemmings; Meteorology; Plovers; Predation; Sandpipers; Shorebirds; Snow; Snowmelt; Temporal variations; Tundra ecology; Turnstones; Winds

G0813
Coats Island, Nunavut; East Bay Migratory Bird Sanctuary, Nunavut; Prince Charles Island, Nunavut; Southampton Island, Nunavut


Ground temperatures in permafrost south of treeline, Mackenzie Delta, Northwest Territories   /   Kanigan, J.C.N.   Burn, C.R.   Kokelj, S.V.
(Special issue : permafrost in the Mackenzie Delta, Canada. Permafrost and periglacial processes, v. 20, no. 2, Apr./June 2009, p. 127-139, ill., map)
(PCSP/PPCP contribution, no. 015-09)
References.
This paper is a contribution from the Environmental Studies Across Treeline project of INAC.
ASTIS record 68578.
Languages: English
Web: doi:10.1002/ppp.643
Libraries: ACU

Surface conditions and ground temperatures from 50-cm to 20-m depth were measured at 26 forested sites in the Mackenzie Delta, to determine if differences in forest structure and organic cover between four common white spruce forest community types were associated with variations in ground temperature. The mean annual temperature at 1-m depth was lowest (-4.4°C) in the closed/spruce-feathermoss (CSF) community associated with a thick canopy and thin snow cover, and highest in the recent permafrost of the spruce/alder-bearberry (SAB) community (-1.0°C) with an open canopy and deep snow. The open-canopy spruce/crowberry-lichen (SCL) forest, with a thick surface organic cover and deep snow, had a higher mean annual temperature at 1-m depth (-2.1°C) than the CSF forest, indicating the importance of canopy cover for snow accumulation and ground heat loss in winter. Seasonal and inter-annual variation of 4-m ground temperatures was greatest beneath the CSF community, highlighting the importance of greater winter cooling due to a thin snow cover and a lower unfrozen water content. Temperatures at 20-m depth ranged from -0.6°C to -1.5°C in SAB forests, and were significantly lower in CSF, open/spruce-feathermoss and SCL communities (-1.6°C to -2.9°C). Variation in near-surface temperatures between spruce forest types diminishes with depth due to the thermal influence of water bodies. There was no significant variation of ground temperatures at 20-m depth within spruce forest communities in different parts of the delta. (Au)

C, H, J, F, E
Active layer; Atmospheric temperature; Crowberries; Heat transmission; Ice wedges; Lichens; Mathematical models; Measurement; Meteorology; Mosses; Permafrost; Plant cover; Plant succession; Plant-soil relationships; Seasonal variations; Snow; Soil temperature; Spruces; Taiga ecology; Thermal properties; Thickness; Winter ecology

G0812
Aklavik, N.W.T.; Fort McPherson, N.W.T.; Inuvik, N.W.T.; Mackenzie Delta, N.W.T.


Near-surface ground-ice distribution, Kendall Island Bird Sanctuary, western Arctic coast, Canada   /   Morse, P.D.   Burn, C.R.   Kokelj, S.V.
(Special issue : permafrost in the Mackenzie Delta, Canada. Permafrost and periglacial processes, v. 20, no. 2, Apr./June 2009, p. 155-171, ill., maps)
(PCSP/PPCP contribution, no. 016-09)
References.
ASTIS record 68585.
Languages: English
Web: doi:10.1002/ppp.650
Libraries: ACU

The variation in near-surface ground-ice content of the uppermost 1 m of permafrost was examined by drilling at 71 sites within the Kendall Island Bird Sanctuary of the outer Mackenzie Delta, Northwest Territories. Permafrost has aggraded in coastal low-lying alluvial wetlands during the last 1500 to 500 years, and high near-surface ground-ice contents have developed in this saturated environment. In contrast, the ground ice in upland terrain has accumulated since the early Holocene. Permafrost in these uplands has a mean excess-ice content of 24%, lower than in the alluvial wetlands (34%), and ground-ice distribution is inherently more variable in upland terrain than in lowlands. Gravimetric moisture content is statistically related to soil organic-matter content, but the organic-matter content confounds the relation between gravimetric moisture and excess-ice content due to its low bulk density. Topographically controlled moisture availability and soil organic-matter content are important to ground-ice distribution in uplands, given the order of magnitude increase in gravimetric moisture contents downslope, and the occurrence of massive ice lenses over 50 cm thick at the base of slopes. The potential mean subsidence of alluvial wetlands due to thawing of the uppermost 1 m of permafrost is 34 cm. Such subsidence would substantially increase the frequency of flooding for portions of this area. (Au)

C, A, F, Q, D
Active layer; Boreholes; Density; Design and construction; Drilling; Floods; Geomorphology; Gravel; Ground ice; Islands; Mackenzie Gas Project; Mathematical models; Measurement; Natural gas processing facilities; NGL pipelines; Permafrost; Permafrost surveys; Runoff; Sand; Sea level; Slopes; Soil moisture; Soil temperature; Spatial distribution; Subsidence; Thawing; Thermokarst; Thickness; Wetlands

G0812
Kendall Island Migratory Bird Sanctuary, N.W.T.; Mackenzie Delta, N.W.T.


The thermal regime of permafrost and its susceptibility to degradation in upland terrain near Inuvik, N.W.T.   /   Burn, C.R.   Mackay, J.R.   Kokelj, S.V.
(Special issue : permafrost in the Mackenzie Delta, Canada. Permafrost and periglacial processes, v. 20, no. 2, Apr./June 2009, p. 221-227, ill., map)
(PCSP/PPCP contribution, no. 017-09)
References.
ASTIS record 68590.
Languages: English
Web: doi:10.1002/ppp.649
Libraries: ACU

Mean near-surface ground temperatures in upland terrain near Inuvik range between -4°C and -1.2°C and the thickness of permafrost is about 90 m. The warm permafrost is due to the relatively deep snow cover that accumulates in the open-canopy forest. Changes in surface conditions may lead to permafrost degradation in this environment, as is evident from elevated ground temperatures beneath disturbed surfaces in a gravel pit, in terrain burned by forest fire and where the snow depth has been increased by fencing. The values for mean annual ground temperature near Inuvik are lower end-members of the distribution of ground temperatures in the boreal forests of northwest Canada. The range in the mean temperature of near-surface permafrost throughout this 1200-km wide belt (from 0°C to about -4°C) is comparable to the range over 100 km northwards from Inuvik across the treeline (from about -4°C to -8°C). (Au)

C, H, F, B, J, E
Active layer; Climate change; Density; Drilling; Effects monitoring; Fire ecology; Forest fires; Granular resources extraction; Ice wedges; Instruments; Measurement; Patterned ground; Peat; Permafrost; Plant cover; Plant-soil relationships; Snow; Snow fences; Soil temperature; Subsidence; Taiga ecology; Thawing; Thermal properties; Thermal regimes; Thickness

G0812, G0811
Inuvik region, N.W.T.; Mackenzie Delta, N.W.T.; Yukon


Habitat selection and the scale of ghostly coexistence among Arctic rodents   /   Ale, S.B.   Morris, D.W.   Dupuch, A.   Moore, D.E.
(Oikos, v.120, no. 8, Aug. 2011, p.1191-1200, ill.)
(PCSP/PPCP contribution, no. 018-09)
References.
ASTIS record 75144.
Languages: English
Web: doi:10.1111/j.1600-0706.2010.18933.x
Libraries: ACU

Competition between coexisting species existing near their stable equilibrium can be obscured if they occupy separate habitats. Theories of habitat selection promise an ability to reveal the underlying ghost of competition by using isodars to infer the behavioural map of habitat selection. We tested the theory with two years of data on abundance and habitat preference by three Arctic rodent species living at low density along a gradient of wet to dry tundra on Herschel Island in Canada's western Arctic. Generalist brown lemmings exhibited a constant partial preference toward wet tundra whereas specialist collared lemmings and voles occupied the driest and wettest zones respectively. Although both lemming species compete for habitats elsewhere in the Canadian Arctic, isodar analyses suggest that the three species occupy wet and dry habitats independently of one another on Herschel Island. Competition at this large scale may be hidden at low densities, however, if the wet-dry dichotomy is too coarse. Analyses at a finer subdivision of habitat revealed that these species coexist by using different microhabitats. Collared lemmings shifted their niche towards even drier habitat as the abundance of brown lemmings increased. We were thus able to reveal the ghost of competition lurking at large scales through a more refined analysis at smaller scales of density-dependent habitat use. (Au)

I, J, H, A
Animal behaviour; Animal distribution; Animal live-capture; Animal population; Chipmunks; Evolution (Biology); Hummocks; Lemmings; Meadows; Mice; Plant cover; Plants (Biology); Sedges; Temporal variations; Tundra ecology; Voles; Weasels; Wildlife habitat

G0811
Herschel Island, Yukon


Phytoplankton and phytobenthos pigment strategies : implications for algal survival in the changing Arctic   /   Bonilla, S.   Rautio, M.   Vincent, W.F.
(Polar biology, v. 32, no. 9, Sept. 2009, p.1293-1303, ill., maps)
(PCSP/PPCP contribution, no. 019-09)
References.
Electronic supplementary material is contained in the online version of this article and is available to authorized users.
ASTIS record 71788.
Languages: English
Web: http://www.springerlink.com/content/y2214n13425p980g/fulltext.pdf
Web: doi:10.1007/s00300-009-0626-1
Libraries: ACU

We compared phytoplankton and phytobenthos pigment strategies in 17 shallow lakes and ponds from northern Canada and Alaska, sampled during mid to late summer. [4/17 were located in Alaska, 3 were near Resolute, 6 were on Ellesmere and Ward Hunt Island, and 4 sites were in N. Québec.] Benthic chlorophyll a concentrations (8-261 mg/m²) greatly exceeded those of the phytoplankton (0.008-1.4 mg/m²) in all sites. Cyanobacteria dominated the phytobenthos, while green algae and fucoxanthin-groups characterized the plankton. Both communities had higher photoprotection in cold, UV-transparent, high latitude waters. Phytoplankton had higher concentrations of photoprotective carotenoids per unit chlorophyll a than the phytobenthos. The planktonic photoprotective pigments were positively correlated with UV-penetration, and inversely correlated with temperature and coloured dissolved organic matter. A partial redundancy analysis showed that the benthic pigments were related to latitude, area and temperature. The UV-screening compound scytonemin occurred in high concentrations in the phytobenthos and was inversely related to temperature, while benthic carotenoids per unit chlorophyll a showed much lower variability among sites. These differing pigment strategies imply divergent responses to environmental change between the phytobenthos and phytoplankton in high latitude lakes. (Au)

E, F, G, J, I, H
Adaptation (Biology); Algae; Atmospheric temperature; Benthos; Biological sampling; Biomass; Carbon cycling; Carotenoids; Chlorophyll; Chromatography; Climate change; Cold adaptation; Colored dissolved organic matter; Cyanophyceae; Diatoms; Evaporation; Fresh-water ecology; Ice cover; Lake stratification; Lakes; Light; Microbial ecology; Photosynthesis; Plankton; Primary production (Biology); Solar radiation; Spectroscopy; Suspended solids; Temperature; Thermal regimes; Tundra ponds; Ultraviolet radiation

G06, G0813, G0826
Alaska, Northern; Hazen, Lake, region, Nunavut; Nouveau-Québec; Resolute region, Nunavut; Ward Hunt Island, Nunavut


Integrating traditional ecological knowledge and ecological science : a question of scale   /   Gagnon, C.A.   Berteaux, D.
(Ecology and society : a journal of integrative science for resilience and sustainability, v. 14, no. 2, Dec. 2009, [26] p., ill., maps)
(PCSP/PPCP contribution, no. 020-09)
References.
Three appendices may be downloaded by clicking on the links provided in the article.
This free access online journal is available on the Web.
ASTIS record 70394.
Languages: English
Web: http://www.ecologyandsociety.org/vol14/iss2/art19/
Libraries: ACU

The benefits and challenges of integrating traditional ecological knowledge and scientific knowledge have led to extensive discussions over the past decades, but much work is still needed to facilitate the articulation and co-application of these two types of knowledge. Through two case studies, we examined the integration of traditional ecological knowledge and scientific knowledge by emphasizing their complementarity across spatial and temporal scales. We expected that combining Inuit traditional ecological knowledge and scientific knowledge would expand the spatial and temporal scales of currently documented knowledge on the arctic fox (Vulpes lagopus) and the greater snow goose (Chen caerulescens atlantica), two important tundra species. Using participatory approaches in Mittimatalik (also known as Pond Inlet), Nunavut, Canada, we documented traditional ecological knowledge about these species and found that, in fact, it did expand the spatial and temporal scales of current scientific knowledge for local arctic fox ecology. However, the benefits were not as apparent for snow goose ecology, probably because of the similar spatial and temporal observational scales of the two types of knowledge for this species. Comparing sources of knowledge at similar scales allowed us to gain confidence in our conclusions and to identify areas of disagreement that should be studied further. Emphasizing complementarities across scales was more powerful for generating new insights and hypotheses. We conclude that determining the scales of the observations that form the basis for traditional ecological knowledge and scientific knowledge represents a critical step when evaluating the benefits of integrating these two types of knowledge. This is also critical when examining the congruence or contrast between the two types of knowledge for a given subject. (Au)

T, I, N, J, L
Aerial surveys; Aircraft disturbance; Animal distribution; Animal ecology; Animal food; Animal migration; Animal population; Arctic foxes; Biology; Bird nesting; Co-management; Common Eiders; Denning; Ecology; Elders; Fur trade; Greater Snow Geese; Helicopters; Hunting; Inuit; Natural area preservation; Noise; Participatory action research; Plumage; Red foxes; Research; Research personnel; Science; Snowmobiles; Social surveys; Temporal variations; Traditional knowledge; Wildlife habitat; Wildlife management; Winter ecology

G0813
Bylot Island, Nunavut; Pond Inlet (Hamlet), Nunavut; Sirmilik National Park, Nunavut


The environment and permafrost of the Mackenzie Delta area   /   Burn, C.R.   Kokelj, S.V.
(Special issue : permafrost in the Mackenzie Delta, Canada. Permafrost and periglacial processes, v. 20, no. 2, Apr./June 2009, p. 83-105, ill., maps)
(PCSP/PPCP contribution, no. 021-09)
References.
ASTIS record 68574.
Languages: English
Web: doi:10.1002/ppp.655
Libraries: ACU

The Mackenzie Delta, prograding northwestwards into the Beaufort Sea, is North America's largest arctic delta. This Holocene feature is bounded by rolling uplands to the east and the Richardson Mountains to the west. Treeline traverses the region, separating the subarctic boreal forest in southern parts from low-shrub tundra and sedge wetlands at the coast. The region is experiencing rapid climate change, and mean annual air temperature has increased by more than 2.5°C since 1970. The area was at the margin of the Wisconsinan ice sheet, so that in the uplands the mean annual ground temperature and glacial history control permafrost thickness, which varies from >700m to <100m. Ground temperatures in the delta are distinct from the uplands due to the thermal influence of numerous lakes and shifting channels. In the uplands, ground temperatures decrease northwards across treeline in association with a decrease in the thickness of snow cover. Ground temperatures have increased since 1970 in the uplands by approximately 1.5°C in association with rising annual mean air temperature. The increase has been less in the delta south of treeline due to the extensive thermal influence of water bodies on ground temperature. However, in the outer delta, the ground is currently more than 2.5°C warmer than in 1970. The impact of climate change on permafrost is also evident in the thickness of the active layer, which increased on average by 8 cm at 12 tundra sites on northern Richards Island from 1983-2008. (Au)

C, Q, E, F, A, H
Active layer; Atmospheric temperature; Climate change; Design and construction; Gas pipelines; Glacial geology; Glaciation; Ground ice; Hydrology; Ice wedges; Lakes; Laurentide Ice Sheet; Mackenzie Gas Project; Mapping; Measurement; Meteorology; Permafrost; Permafrost surveys; Pingos; Plant-soil relationships; Research; River deltas; Rivers; Seasonal variations; Sedimentation; Snow; Soil temperature; Temporal variations; Thaw flow slides; Thawing; Treeline; Water level

G0812, G0811
Mackenzie Delta, N.W.T.; Mackenzie Delta, Yukon; Mackenzie River region, N.W.T.; Richards Island, N.W.T.


Postglacial environmental history of western Victoria Island, Canadian Arctic   /   Fortin, M.-C.   Gajewski, K.
(Quaternary science reviews, v. 29, no. 17-18, Aug. 2010, p.2099-2110, ill., maps)
(PCSP/PPCP contribution, no. 022-09)
References.
ASTIS record 73167.
Languages: English
Web: doi:10.1016/j.quascirev.2010.05.004
Libraries: ACU

Changes in chironomid species assemblages and community dynamics at Lake KR02, western Victoria Island were analysed to produce a record of environmental change over the Holocene for the western Arctic. Past air temperatures were inferred from the chironomid record using transfer function and modern analogue techniques, and past lake water pH was reconstructed using sediment carbonate and biogenic silica content. The early-Holocene (10.2-6.5 ka) was a warm period of high aquatic and terrestrial production. A further change in environmental conditions occurred at 4 ka and lasted for the next two millennia. Conditions warmed abruptly at 1.6 ka, and rapidly cooled at 1.0 ka. A warming then started at 0.14 ka and continued through to recent times, although temperatures still remained cooler than those experienced prior to 6.5 ka. The climatic changes over the Holocene as recorded at Lake KR02 are consistent with those inferred from independent records from other sites on Victoria Island and across the Arctic. (Au)

B, E, I, F, H, J
Animal taxonomy; Bottom sediments; Carbonates; Chironomidae; Cores; Diatoms; Lakes; Palaeobotany; Palaeoclimatology; Palaeoecology; Palaeohydrology; Palaeontology; Palynology; Plant taxonomy; Radioactive dating; Radiocarbon dating; Recent epoch; Sedimentation; Water pH

G0812
Kuujjua River region, N.W.T.


High Arctic lakes as sentinel ecosystems : cascading regime shifts in climate, ice cover, and mixing   /   Mueller, D.R.   Van Hove, P.   Antoniades, D.   Jeffries, M.O.   Vincent, W.F.
(Special issue 2009 : lakes and reservoirs as sentinels, integrators, and regulators of climate change / Edited by C.W. Williamson and J.E.G. Saros (coordinating editors) and W.F. Vincent and J.P. Smol (issue editors). Limnology and oceanography, v. 54, no. 6/2, Nov. 2009, p.2371-2385, ill., maps)
(PCSP/PPCP contribution, no. 023-09)
References.
The American Geophysical Union Chapman Conference is also associated with this special issue.
ASTIS record 71785.
Languages: English
Web: http://www.aslo.org/lo/toc/vol_54/issue_6_part_2/2371.pdf
Web: doi:10.4319/lo.2009.54.6_part_2.2371
Libraries: ACU

Climate and cryospheric observations have shown that the high Arctic has experienced several decades of rapid environmental change, with warming rates well above the global average. In this study, we address the hypothesis that this climatic warming affects deep, ice-covered lakes in the region by causing abrupt, threshold-dependent shifts rather than slow, continuous responses. Synthetic aperture radar (SAR) data show that lakes (one freshwater and four permanently stratified) on Ellesmere Island at the far northern coastline of Canada have experienced significant reductions in summer ice cover over the last decade. The stratified lakes were characterized by strong biogeochemical gradients, yet temperature and salinity profiles of their upper water columns (5-20 m) indicated recent mixing, consistent with loss of their perennial ice and exposure to wind. Although subject to six decades of warming at a rate of 0.5°C/decade, these lakes were largely unaffected until a regime shift in air temperature in the 1980s and 1990s, when warming crossed a critical threshold forcing the loss of ice cover. This transition from perennial to annual ice cover caused another regime shift whereby previously stable upper water columns were subjected to mixing. Far northern lakes are responding discontinuously to climate-driven change via a cascade of regime shifts and have an indicator value beyond the regional scale. (Au)

E, F, G, J
Atmospheric temperature; Climate change; Electrical properties; Fresh-water ecology; Ice cover; Lake ice; Lake stratification; Lake-atmosphere interaction; Lakes; Meteorology; Numeric databases; Salinity; SAR; Snow cover; Temperature; Temporal variations; Winds

G0813
Alert, Nunavut; Eureka, Nunavut; Marvin Peninsula, Nunavut


Variability in greenhouse gas emissions from permafrost thaw ponds   /   Laurion, I.   Vincent, W.F.   MacIntyre, S.   Retamal, L.   Dupont, C.   Francus, P.   Pienitz, R.
(Limnology and oceanography, v. 55, no. 1, Jan. 2010, p. 115-133, ill., map)
(PCSP/PPCP contribution, no. 024-09)
References.
ASTIS record 69271.
Languages: English
Web: http://www.cen.ulaval.ca/paleo/Publications/Articles/Laurion.2010.pdf
Web: doi:10.4319/lo.2010.55.1.0115
Libraries: ACU

Arctic climate change is leading to accelerated melting of permafrost and the mobilization of soil organic carbon pools that have accumulated over thousands of years. Photochemical and microbial transformation will liberate a fraction of this carbon to the atmosphere in the form of CO2 and CH4. We quantified these fluxes in a series of permafrost thaw ponds in the Canadian Subarctic and Arctic and further investigated how optical properties of the carbon pool, the type of microbial assemblages, and light and mixing regimes influenced the rate of gas release. Most ponds were supersaturated in CO2 and all of them in CH4. Gas fluxes as estimated from dissolved gas concentrations using a wind-based model varied from -20.5 to 114.4 mmol CO2/m²/d, with negative fluxes recorded in arctic ponds colonized by benthic microbial mats, and from 0.03 to 5.62 mmol CH4/m²/d. From a time series set of measurements in a subarctic pond over 8 d, calculated gas fluxes were on average 40% higher when using a newly derived equation for the gas transfer coefficient developed from eddy covariance measurements. The daily variation in gas fluxes was highly dependent on mixed layer dynamics. At the seasonal timescale, persistent thermal stratification and gas buildup at depth indicated that autumnal overturn is a critically important period for greenhouse gas emissions from subarctic ponds. These results underscore the increasingly important contribution of permafrost thaw ponds to greenhouse gas emissions and the need to account for local and regional variability in their limnological properties for global estimates. (Au)

C, F, E, J, I, H
Active layer; Atmospheric humidity; Atmospheric temperature; Bacteria; Biodegradation; Biological productivity; Carbon; Carbon dioxide; Chlorophyll; Climate change; Environmental impacts; Gases; Heat transmission; Lake stratification; Lake-atmosphere interaction; Light; Methane; Microorganisms; Optical properties; Oxygen; Peat; Permafrost; Phosphorus; Seasonal variations; Size; Soils; Solar radiation; Spatial distribution; Spectroscopy; Suspended solids; Temperature; Temporal variations; Thawing; Thermokarst; Thickness; Tundra ponds; Velocity; Water pH; Winds

G0826, G0813
Kuujjuarapik region, Québec; Sirmilik National Park, Nunavut


Diversité microbienne des mares générées par la fonte du pergélisol en régions arctique et subarctique   /   Dupont, C.   Laurion, I. [Supervisor]
Québec, Québec : Université du Québec, 2009.
xvi, 142 p. : ill., maps ; 28 cm.
(PCSP/PPCP contribution, no. 024-09)
References.
Thesis (M.Sc.) - Université du Québec, INRS, Québec, Québec, 2009.
Indexed a PDF file.
Chapter 2 consists of a manuscript entitled: Microbial diversity of Arctic and Subarctic thaw ponds: characterization using different biological indicators, which is intended to be published separately at a later date.
Partial contents: Appendix: Variability in greenhouse gas omissions from permafrost thaw ponds, as separately published in Limnology and oceanography, and described in ASTIS record 69271.
The Résumé, Chapitre 1, and Discussion Générale et Conclusion, are in French; Chapitre 2 and the Appendix, are in English.
ASTIS record 76346.
Languages: English or French
Web: http://www1.ete.inrs.ca/pub/theses/T000512.pdf
Libraries: OONL

Les mares de fonte sont formées par la dégradation locale du pergélisol en hautes latitudes. Les bouleversements climatiques actuels favorisent leur apparition dans les zones nordiques autour du globe. Les mares subarctiques en zone de pergélisol discontinu ont été échantillonnées au Nunavik au nord du Québec et résultent de l'affaissement de buttes pergélisolées. Elles sont caractérisées par une grande turbidité et une stratification thermique importante. Les mares arctiques en zone de pergélisol continu sont situées au Nunavut sur l'Île Bylot et sont des mares au creux de polygones à coin de glace et des canaux adjacents. Les mares arctiques sont moins profondes, plus transparentes et donc plus illuminées, entraînant la formation de tapis microbiens. Ces deux types de mare nordiques émettent des gaz à effet de serre (principalement du CO2 et du CH4) vers l'atmosphère et attirent de plus en plus l'attention des scientifiques. La diversité microbienne de ces plans d 'eau reste par contre grandement méconnue, de même que les variables limnologiques qui la régissent. Trois approches complémentaires ont été déployées pour caractériser la flore microbienne des mares de fonte : la taxinomie du phytoplancton, l'analyse de pigments diagnostiques et l'analyse moléculaire des picoeukaryotes via le DGGE (denaturing gradient gel electrophoresis). Les mares se sont avérées être très différentes au niveau physique, optique et chimique, tant au sein d'un même site qu'au niveau inter-site. Les mares subarctiques sont souvent dominées par les Chlorophyceae et les Chrysophyceae alors que les Cyanophyceae sont prépondérantes dans les mares arctiques. La diversité microbienne est sensiblement plus faible en zone arctique, tant au niveau phytoplanctonique que pigmentaire. Les assemblages picoeukaryotes (avec le DGGE) varient au sein d'une même mare subarctique entre la surfacee et le fond puisque les conditions limnologiques y sont très différentes. Des analyses statistiques révèlent que parmi les variables mesurées, le KdPAR (la lumière) et la pente spectrale (indice de qualité de la matière organique) seraient les deux facteurs influençant les patrons de répartition phytoplanctoniques. La diversité microbienne des mares de fonte s'est donc un peu dévoilée et des suggestions d'études futures sont finalement abordées. (Au)

C, F, E, J, I, H
Active layer; Atmospheric humidity; Atmospheric temperature; Bacteria; Biodegradation; Biological productivity; Carbon; Carbon dioxide; Chlorophyll; Climate change; Environmental impacts; Gases; Heat transmission; Lake stratification; Lake-atmosphere interaction; Light; Methane; Microorganisms; Optical properties; Oxygen; Peat; Permafrost; Phosphorus; Seasonal variations; Size; Soils; Solar radiation; Spatial distribution; Spectroscopy; Suspended solids; Temperature; Temporal variations; Thawing; Thermokarst; Theses; Thickness; Tundra ponds; Velocity; Water pH; Winds

G0826, G0813
Kuujjuarapik region, Québec; Sirmilik National Park, Nunavut


UV photoprotectants in Arctic zooplankton   /   Rautio, M.   Bonilla, S.   Vincent, W.F.
(Aquatic biology, v. 7, no. 1-2, Nov. 2009, p. 93-105, ill., maps)
(PCSP/PPCP contribution, no. 029-09)
References.
Indexed a PDF file from the Web.
ASTIS record 71786.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/256.pdf
Web: doi:10.3354/ab00184

High latitude zooplankton must contend with continuous ultraviolet (UV) exposure in summer, increased UVB fluxes as a result of stratospheric ozone depletion and little UV protection from their transparent waters. In the present study, we evaluated the presence and concentration of 4 types of UV-protectants in arctic zooplankton: carotenoids, melanins, scytonemin and mycosporine-like amino acids (MAAs). We analysed 12 commonly occurring crustacean species from 27 [sic] freshwater bodies in northern Canada and Alaska. [9 of the 28 water bodies examined were in northern Alaska, 5 were on Ellesmere Island, 5 on Cornwallis Island, 4 in the Mackenzie Delta, and 5 in coastal subarctic northern Quebec.] Pigments were detected in all species, and most populations had multiple pigments, suggesting a combination of photoprotection strategies, including broadband screening of UV radiation and carotenoid quenching of reactive oxygen species. Scytonemin, a UVA-screening pigment of cyanobacterial origin that has not been previously detected in zooplankton, was found in 2 crustacean species: the cladoceran Daphnia middendorffiana and the fairy shrimp Branchinecta paludosa. MAAs were detected in all populations, providing the first records of high concentrations of these compounds in the genus Daphnia (1 µg/mg) and in the fairy shrimp Artemiopsis stefanssoni (up to 37 µg/mg). Concurrent analyses of food sources showed that scytonemin, carotenoids and MAAs in zooplankton originated in phytoplankton or benthic algal mats. Thus, in addition to providing a measure of UV protection, the pigments also indicate zooplankton food sources and potential benthic-pelagic coupling. (Au)

I, F, E, J, G, H
Adaptation (Biology); Amino acids; Animal food; Benthos; Carotenoids; Chromatography; Crustacea; Cyanophyceae; Daphnia; Food chain; Fresh-water ecology; Lake ice; Lakes; Ozone; Phytoplankton; Seasonal variations; Shrimp; Trophic levels; Tundra ponds; Ultraviolet radiation; Zooplankton

G06, G081
Alaska, Northern; Canadian Arctic; Cornwallis Island, Nunavut; Ellesmere Island, Nunavut; Kuujjuarapik region, Québec; Mackenzie Delta, N.W.T.; Umiujaq region, Québec


Bacterial dominance of phototrophic communities in a High Arctic lake and its implications for paleoclimate analysis   /   Antoniades, D.   Veillette, J.   Martineau, M.-J.   Belzile, C.   Tomkins, J.   Pienitz, R.   Lamoureux, S.   Vincent, W.F.
(MERGE / Edited by H. Kanda, P. Convey, T. Naganuma, W. Vincent, and A. Wilmotte. Polar science, v. 3, no. 3, Nov. 2009, p. 147-161, ill., maps)
(PCSP/PPCP contribution, no. 031-09)
References.
ASTIS record 70402.
Languages: English
Web: doi:10.1016/j.polar.2009.05.002
Libraries: ACU

The phototrophic communities in meromictic, perennially ice-covered Lake A, on Ellesmere Island in the Canadian High Arctic, were characterized by pigment analysis using high performance liquid chromatography. Samples were taken to determine the vertical changes down the water column as well as a variation between years. These analyses showed that Lake A had distinct phototrophic communities in its oxic and anoxic layers. The pigment analyses indicated that phototrophic biomass in the upper, oxic waters was dominated by picocyanobacteria, while in the lower, anoxic layer photosynthetic green sulphur bacteria were dominant. Interannual variation in pigment concentrations was related to the penetration of photosynthetically active radiation in the water column, suggesting that light availability may be limiting the net accumulation of photosynthetic bacterial biomass in Lake A. Pigment analysis of the surface sediments indicated that deposition was dominated by the photosynthetic sulphur bacterial contribution. The sedimentary record of bacterial pigments in polar meromictic lakes offers a promising tool for the reconstruction of past changes in ice cover and therefore in climate. (Au)

F, H, I, J, G, B, E
Albedo; Atmospheric temperature; Bacteria; Biological sampling; Bottom sediments; Carotenoids; Chlorophyll; Chromatography; Climate change; Cyanophyceae; Environmental impacts; Fluorometry; Ice cover; Lake ice; Lake stratification; Lakes; Light; Microbial ecology; Oxygen; Palaeoclimatology; Palaeoecology; Photosynthesis; Phytoplankton; Salinity; Sedimentation; Snow; Snow cover; Spatial distribution; Spectroscopy; Sulphur; Temperature; Temporal variations; Thickness; Water pH; Zooplankton

G0813
Marvin Peninsula, Nunavut


Arctic microbial ecosystems and impacts of extreme warming during the International Polar Year   /   Vincent, W.F.   Whyte, L.G.   Lovejoy, C.   Greer, C.W.   Laurion, I.   Suttle, C.A.   Corbeil, J.   Mueller, D.R.
(MERGE / Edited by H. Kanda, P. Convey, T. Naganuma, W. Vincent, and A. Wilmotte. Polar science, v. 3, no. 3, Nov. 2009, p. 171-180, ill., maps)
(PCSP/PPCP contribution, no. 032-09)
References.
ASTIS record 69272.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/253.pdf
Web: doi:10.1016/j.polar.2009.05.004
Libraries: ACU

As a contribution to the International Polar Year program MERGE (Microbiological and Ecological Responses to Global Environmental change in polar regions), studies were conducted on the terrestrial and aquatic microbial ecosystems of northern Canada (details at: http://www.cen.ulaval.ca/merge/). The habitats included permafrost soils, saline coldwater springs, supraglacial lakes on ice shelves, epishelf lakes in fjords, deep meromictic lakes, and shallow lakes, ponds and streams. Microbiological samples from each habitat were analysed by HPLC pigment assays, light and fluorescence microscopy, and DNA sequencing. The results show a remarkably diverse microflora of viruses, Archaea (including ammonium oxidisers and methanotrophs), Bacteria (including filamentous sulfur-oxidisers in a saline spring and benthic mats of Cyanobacteria in many waterbodies), and protists (including microbial eukaryotes in snowbanks and ciliates in ice-dammed lakes). In summer 2008, we recorded extreme warming at Ward Hunt Island and vicinity, the northern limit of the Canadian high Arctic, with air temperatures up to 20.5 °C. This was accompanied by pronounced changes in microbial habitats: deepening of the permafrost active layer; loss of perennial lake ice and sea ice; loss of ice-dammed freshwater lakes; and 23% loss of total ice shelf area, including complete break-up and loss of the Markham Ice Shelf cryo-ecosystem. These observations underscore the vulnerability of Arctic microbial ecosystems to ongoing climate change. (Au)

E, J, F, C, I, H, G, B
Active layer; Animal distribution; Animal population; Archaea; Atmospheric temperature; Bacteria; Biological sampling; Bottom sediments; Breakup; Climate change; Cyanophyceae ; Environmental impacts; Genetics; Glacier lakes; Ice shelves; Lake ice; Lake stratification; Lakes; Melting; Methane; Microbial ecology; Microorganisms; Permafrost; Plankton; Plant distribution; Protozoa; Puddles; Rivers; Sea ice; Snow; Soil temperature; Soils; Spatial distribution; Springs (Hydrology); Thawing; Thermokarst; Thickness; Tundra ponds; Viruses; Wildlife habitat

G0813, G03, G0826, G0812
Ayles Fiord, Nunavut; Bylot Island, Nunavut; Disraeli Fiord, Nunavut; Expedition Fiord region, Nunavut; Kuujjuarapik region, Québec; M'Clintock Inlet, Nunavut; Mackenzie Delta, N.W.T.; Markham Fiord, Nunavut; Milne Fiord, Nunavut; Milne Ice Shelf, Nunavut; Nansen Sound, Nunavut; Petersen Bay, Nunavut; Phillips Inlet, Nunavut; Serson Ice Shelf, Nunavut; Umiujaq region, Québec; Ward Hunt Ice Shelf, Nunavut; Ward Hunt Island, Nunavut; Yelverton Bay, Nunavut


Moss carpets constrain the fertilizing effects of herbivores on graminoid plants in Arctic polygon fens   /   Pouliot, R.   Rochefort, L.   Gauthier, G.
(Botany, v. 87, no. 12, Dec. 2009, p.1209-1222, ill.)
(PCSP/PPCP contribution, no. 034-09)
Appendix.
References.
ASTIS record 74048.
Languages: English
Web: doi:10.1139/B09-069
Libraries: ACU

We conducted a fertilization experiment in polygon fens that were grazed by Greater Snow Geese on Bylot Island (Canadian Arctic) to determine whether mosses can interfere with nutrient cycling and thereby prevent a direct fertilizing effect of herbivore faeces on vascular plants. We measured the effects of nitrogen (N), phosphorus (P), and faecal addition on growth parameters and nutrient content of graminoids and mosses over a 2 year period. Growth and nutrient content of graminoids were enhanced only for high levels of N addition (5 g/m² per season), and showed little response to P addition. Although the growth of mosses showed a slight response to N or P addition, it is primarily nutrient content that was generally enhanced at all levels of fertilization. In many cases, stronger responses were detected when N and P were applied in combination, rather than singly. Addition of goose droppings had no effect on any measured parameters. Our results suggest that bryophytes act as a natural barrier by absorbing nutrients from external additions, thus blocking the access of highly assimilable nutrients to graminoid plant roots. At increased levels of N addition, bryophytes were apparently saturated so the nutrient surplus leached down to roots and was thus available for graminoid plant growth. The presence of a thick moss layer likely explains why the deposition of faeces by herbivores such as geese has no effect on graminoid growth in arctic polygon fens. (Au)

H, I, N, J
Animal food; Animal waste products; Biological sampling; Biomass; Fertilizers; Flowers; Grasses; Grazing; Greater Snow Geese; Leaves; Manures; Mosses; Nitrogen; Nitrogen cycling; Peat; Phosphorus; Plant growth; Plant nutrition; Primary production (Biology); Roots; Sedges; Trophic levels; Wetlands

G0813
Bylot Island, Nunavut


Global distribution of cyanobacterial ecotypes in the cold biosphere   /   Jungblut, A.D.   Lovejoy, C.   Vincent, W.F.
(The ISME journal, v. 4, no. 2, Feb. 2010, p. 191-202, ill.)
(PCSP/PPCP contribution, no. 041-09)
References.
Supplementary information (2 figures and 4 tables) accompanies the paper on The ISME Journal website (http://www.nature.com/ismej).
ASTIS record 71780.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/259.pdf
Web: doi:10.1038/ismej.2009.113
Libraries: ACU

Perennially cold habitats are diminishing as a result of climate change; however, little is known of the diversity or biogeography of microbes that thrive in such environments. Here we use targeted 16S rRNA gene surveys to evaluate the global affinities of cold-dwelling cyanobacteria from lake, stream and ice communities living at the northern limit of High Arctic Canada. Pigment signature analysis by HPLC confirmed the dominance of cyanobacteria in the phototrophic communities of these High Arctic microbial mats, with associated populations of chlorophytes and chromophytes. Microscopic analysis of the cyanobacteria revealed a diverse assemblage of morphospecies grouping into orders Oscillatoriales, Nostocales and Chroococcales. The 16S rRNA gene sequences from six clone libraries grouped into a total of 24 ribotypes, with a diversity in each mat ranging from five ribotypes in ice-based communities to 14 in land-based pond communities. However, no significant differences in composition were observed between these two microbial mat systems. Based on clone-library and phylogenetic analysis, several of the High Arctic ribotypes were found to be >99% similar to Antarctic and alpine sequences, including to taxa previously considered endemic to Antarctica. Among the latter, one High Arctic sequence was found 99.8% similar to Leptolyngbya antarctica sequenced from the Larsemann Hills, Antarctica. More than 68% of all identified ribotypes at each site matched only cyanobacterial sequences from perennially cold terrestrial ecosystems, and were <97.5% similar to sequences from warmer environments. These results imply the global distribution of low-temperature cyanobacterial ecotypes throughout the cold terrestrial biosphere. (Au)

H, E, J, G, F
Alpine tundra ecology; Biomass; Bottom sediments; Chlorophyll; Chromatography; Classification; Climate change; Cold adaptation; Cyanophyceae; Electrical properties; Fluorometry; Genetics; Ice shelves; Instruments; Lakes; Mass spectrometry; Microbial ecology; Nitrogen; Photosynthesis; Physical properties; Plant distribution; Plant nutrition; Puddles; Rivers; Spectroscopy; Tundra ponds; Ultraviolet radiation; Water pH

G01, G0815, G0813, G15
Bonney, Lake, Antarctic regions; China; Fryxell, Lake, Antarctic regions; Larsemann Hills, Antarctic regions; Markham Fiord, Nunavut; Polar regions; Quttinirpaaq National Park, Nunavut; Ward Hunt Island, Nunavut


Raised gravel beaches as proxy indicators of past sea-ice and wave conditions, Lowther Island, Canadian Arctic Archipelago   /   St-Hilaire-Gravel, D.   Bell, T.J.   Forbes, D.L.
(Arctic, v. 63, no. 2, June 2010, p. 213-226, ill., maps)
(PCSP/PPCP contribution, no. 042-09)
References.
This paper is ESS (Earth Sciences Sector) contribution number 20090112.
ASTIS record 70559.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic63-2-213.pdf
Web: doi:10.14430/arctic976
Libraries: ACU

This study investigates whether raised beach sequences preserved on emergent coasts of the central Canadian Arctic Archipelago contain a proxy record of past sea-ice conditions and wave intensity. We hypothesize that periods of reduced sea ice (increased open water) expose shorelines to more prolonged and higher wave energy, leading to better-developed beach ridges. Surveys of raised beach sequences on Lowther Island revealed the following patterns: a) high, wide, single- to multi- crested barriers backed by deep swales or lagoons characterize both the active and lowest relict shorelines; b) small, narrow, discontinuous ridges of poorly sorted gravel extend from 1.0 to 7.5 m asl, except from 4.5 to 5.0 m asl; c) ridge morphology is similar to the active and first relict ridges between 7.5 and 11 m asl; d) a near-featureless zone with minor terraces and ridges above 11 m extends to above 30 m asl. These distinct morphological and sedimentary units are interpreted as a function of wave climate and thus of summer sea-ice conditions. This model suggests periods of greater wave activity from the present day back about 500 14C years (530 cal BP; Unit A), during a short interval from 1750 to 1600 14C years BP (1750-1450 cal BP; Unit B'), and earlier from 2900 to 2300 14C years BP (3030-2340 cal BP; Unit C). Units B and D are interpreted as the result of more severe ice conditions with lower wave energy from 2300 to 500 14C years BP (2340-530 cal BP) and earlier from more than 5750 to 2900 14C years BP (6540-3030 cal BP). Discrepancies with previously published interpretations of regional sea-ice history may reflect the local nature of the beach proxy record, which implies occurrences of extensive open-water fetch east and west of Lowther Island but cannot be extrapolated to a regional scale. The beach record shows distinct variation through time and provides an alternative window on past summer ice extent in central Barrow Strait. (Au)

A, B, G, D, E
Bathymetry; Beaches; Climatology; Coast changes; Geomorphology; Ice cover; Ocean waves; Palaeohydrology; Radiocarbon dating; Recent epoch; Sea ice; Sea level; Seasonal variations; Sedimentation; Shorelines; Storm surges; Temporal variations

G0815, G0813
Barrow Strait, Nunavut; Lowther Island, Nunavut


Polar lakes and rivers : limnology of Arctic and Antarctic aquatic ecosystems   /   Vincent, W.F. [Editor]   Laybourn-Parry, J. [Editor]
Oxford, U.K. : Oxford University Press, 2008.
xviii, 327 p., [16] p. of plates : ill., maps ; 26 cm.
(PCSP/PPCP contribution, no. 043-09)
ISBN 978-0-19-921388-7
Appendix.
References.
This book is endorsed by the International Polar Year 2007-2008.
Sixteen pages of colour plates are between p. 158 and 159.
ASTIS record 66525.
Languages: English
Libraries: ACU

This is the first book to describe the ecology of high latitude lakes, rivers, and glacial environments in both the North and South polar regions. From the lake-rich floodplains of the Arctic to the deep, enigmatic waters of Lake Vostok, Antarctica, these regions contain some of the most extraordinary aquatic ecosystems on Earth. They provide a fascinating diversity of habitats for plant, animal and microbial communities, and are proving to be valuable model systems for exploring many ecological themes including landscape-lake interactions, adaptation of life to environmental extremes, and controls on the structure and functioning of aquatic ecosystems. Some of these waters also have direct global implications, including permafrost thaw lakes as sources of greenhouse gases, subglacial aquatic environments as a storehouse of ancient microbes, and Arctic rivers as major inputs of freshwater and organic carbon to the World Ocean. Given that many polar areas are experiencing greater climate warming than at lower latitudes, these ecosystems can also be viewed as sentinels of global change. This timely volume brings together many of the world's leading researchers in polar limnology to describe these diverse aquatic environments and their ecology. It introduces each major ecosystem type, examines the similarities and differences between Arctic and Antarctic systems as well as their responses to environmental change, and describes new frontiers for future research. A glossary of terms is provided for non-specialists, and a set of colour plates introduces the ecosystems and their biota. "Polar Lakes and Rivers" will be of value to students and specialist researchers alike, as well as to those with a more general interest in aquatic ecology, polar environments or global change who require an authoritative overview of this fast emerging topic. (Au)

F, J, I, H, A, G, E, D
Animal population; Benthos; Biological productivity; Biomass; Carbon; Carbon cycling; Climate change; Cold adaptation; Cryoconite; Environmental impacts; Fishes; Food chain; Formation; Fresh-water ecology; Geomorphology; Glacier lakes; Glaciers; Heavy metals; Ice shelves; Lake ice; Lake stratification; Lake-atmosphere interaction; Lakes; Light; Microbial ecology; Plankton; Plant nutrition; Plants (Biology); Pollution; POPs; Primary production (Biology); Puddles; Radionuclides; Rivers; Sea level; Snow; Temperature; Temporal variations; Tundra ponds; Ultraviolet radiation; Wildlife habitat

G02, G15
Antarctic regions; Arctic regions


Spatial patterns of snow accumulation across the Belcher Glacier basin, Devon Island, Nunavut, Canada   /   Sylvestre, T.J.   Copland, L. [Supervisor]
Ottawa : University of Ottawa, 2009.
xvi, 145 p. : ill., maps ; 28 cm.
(Proquest Dissertations & Theses publication, no. MR61270)
(PCSP/PPCP contribution, no. 044-09)
ISBN 978-0-494-61270-5
Thesis (M.Sc.) - University of Ottawa, Ottawa, Ont., 2009.
Indexed from a PDF file acquired from ProQuest Dissertations & Theses.
Appendix.
References.
ASTIS record 71815.
Languages: English
Libraries: OONL

In May 2008, high frequency ground penetrating radar (GPR) surveys were conducted on the Belcher Glacier Basin, Devon Ice Cap, and validated with avalanche probe measurements to map the thickness and spatial variability of winter (2007-8) snow. The GPR record was combined with field measurements using a neutron density probe and correlated with NCEPNCAR climate reanalysis, QSCAT satellite records, and airborne ASIRAS data to derive multi-year snow accumulation patterns across the basin from 2005-7. The distinct characteristics of the GPR record from the surface to 3 m depth were related to the 2007 and 2005 summer surfaces. GPR derived depths to these surfaces and the assessment of the average annual accumulation rate across this basin correlate very well with previous snow accumulation assessments in other parts of Devon Ice Cap (Mair et al. 2005, Colgan et al. 2008 and Koerner 1977). The complex radar returns in the LSS-05 depth range appear to be related to extensive melt processes during summer 2005, together with a large rain event in summer 2006, which produced large quantities of meltwater at all elevations of Devon Ice Cap. The major broad-scale control factor in determining annual and multiyear snow depth patterns for the basin is elevation, with surface topography and distance from the moisture source being locally important. GPR enabled the position of the basin-wide snow line to be determined by observing internal layers emerging at the surface, with the superimposed ice facies and equilibrium line altitude inferred below this altitude. (Au)

F, E
Accumulation; Boreholes; Climate change; Density; Effects of climate on ice; Glacial melt waters; Glaciers; Ground penetrating radar; Hydrology; Ice caps; Mass balance; Measurement; Radar; Remote sensing; SAR; Satellite photography; Seasonal variations; Snow; Snow stratigraphy; Snow surveys; Snowmobiles; Spatial distribution; Theses; Thickness; Topography

G0813
Belcher Glacier, Nunavut; Devon Ice Cap, Nunavut


Spatial heterogeneity of primary production as both cause and consequence of foraging patterns of an expanding Greater Snow Goose colony   /   Valéry, L.   Cadieux, M.-C.   Gauthier, G.
(Écoscience, v. 17, no 1, Mar. 2010, p. 9-19, ill., maps)
(PCSP/PPCP contribution, no. 045-09)
References.
ASTIS record 70401.
Languages: English
Web: doi:10.2980/17-1-3279
Libraries: ACU

In response to spatial heterogeneity of resources, many herbivores move between discrete areas to enhance access to the best foraging areas. Local forage removal by mobile herd-foraging herbivores in turn is likely to produce spatial variability in both plant nutritive quality and quantity. On the tundra of Bylot Island, Nunavut, owing to the recent demographic explosion of their population, most greater snow geese move out of their nesting area soon after hatch to rear their young at distant feeding sites. A previous study showed that goslings using these distant sites are generally heavier and larger than those that stay in the colony throughout the brood-rearing period. In this study, we examine the hypothesis that goslings' growth was reduced in the nesting area compared to distant brood-rearing areas because grazing pressure reduced standing crop. In light of the recent expansion in the distribution of geese during brood-rearing, we also investigated if the negative effect of chronic grazing on net above-ground primary production (NAPP) differed between the colony and distant brood-rearing sites. We monitored NAPP, grazing pressure, and intensity of use in the goose colony and in 2 distant brood-rearing areas over a 10-y period by sampling plant biomass inside and outside moveable goose exclosures erected annually and by counting goose feces along transects at the end of the summer. NAPP of graminoids in the nesting area was 40% lower than at the other brood-rearing areas, but the percentage of primary production consumed by geese (28%) did not differ among the 3 sites despite large annual variations. Cumulative feces density revealed that intensity of use of the 2 brood-rearing areas by geese was nearly 2 times higher than at the colony, but the timing of use differed as grazing on the brood-rearing areas occurred only after hatch, unlike the nesting area. We conclude that geese not only respond to spatial heterogeneity in resource availability but also create and sustain it through their foraging behaviour. (Au)

I, H, J
Animal behaviour; Animal distribution; Animal food; Animal growth; Animal population; Animal waste products; Biomass; Bird nesting; Environmental impacts; Grasses; Grazing; Greater Snow Geese; Plant nutrition; Plants (Biology); Primary production (Biology); Temporal variations; Tundra ecology; Wetlands

G0813
Bylot Island, Nunavut


Endorhizal fungi in Ranunculus from western and Arctic Canada : predominance of fine endophytes at high latitudes   /   Walker, X.J.   Basinger, J.F.   Kaminskyj, S.G.W.
(The open mycology journal, v. 4, 2010, p. 1-9, ill., map)
(PCSP/PPCP contribution, no. 046-09)
References.
ASTIS record 75903.
Languages: English
Web: doi:10.2174/1874437001004010001
Libraries: ACU

Ranunculus roots were sampled across a latitudinal transect encompassing 52 °N and 82 °N, for years spanning 1963-2007. Samples from 2004 and later were preserved in formalin; earlier samples were taken from herbarium accessions. Roots were examined for colonization by arbuscular mycorrhizae, fine endophyte, and septate endophyte fungi using lactofuchsin-stained material imaged with epifluorescence microscopy. Endorhizal quantitation was assessed for each endorhizal morphotype. Roots from High Arctic (79 °N-82 °N) and mid-latitude (52 °N-54 °N) sites both contained all three endorhizal morphotypes; however, overall fungal colonization was almost three-fold higher in midlatitude samples. Most Ranunculus root colonization (29 % of the root length) in High Arctic samples was from fine endophyte fungi, whereas fine endophyte colonization was ~ 20 % of root length in mid-latitude roots. In contrast, arbuscular mycorrhizal colonization was 2 % of root length in High Arctic samples and 57 % in mid-latitude samples. Septate endophyte colonization was 11 % and 36 % of root length for High Arctic and mid-latitude samples, respectively. These values are consistent with our previous results for other taxa, and suggest that fine endophytes are important contributors to soil microbial diversity as related to plant survival and competitiveness in the high latitudes. (Au)

H, J, C
Biomass; Fluorometry; Fungi; Microscopes; Mycorhizal fungi; Plant collections; Plant distribution; Plant growth; Ranunculaceae; Revegetation; Soil microorganisms; Temporal variations; Tundra ecology

G0813, G0811, G0821, G0823, G0812
Axel Heiberg Island, Nunavut; Banks Island, N.W.T.; British Columbia; Bylot Island, Nunavut; Ellesmere Island, Nunavut; Saskatchewan; Yukon


Connections between river runoff and limnological conditions in adjacent High Arctic lakes : Cape Bounty, Melville Island, Nunavut   /   Stewart, K.A.   Lamoureux, S.F.
(Arctic, v. 64, no. 2, June 2011, p. 169-182, ill., maps)
(PCSP/PPCP contribution, no. 047-09)
References.
ASTIS record 74016.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic64-2-169.pdf
Web: doi:10.14430/arctic4097
Libraries: ACU

Hydrological and hydrochemical monitoring of paired watersheds in the High Arctic was conducted in 2003-04 to investigate the influence of seasonal runoff on lake water chemistry and productivity. Despite similar limnological conditions overall between the two lakes, marked differences in aquatic productivity were attributed to watershed and basin morphology and the resultant influences on lake ice deterioration and growing season length. A switch from allochthonous to autochthonous sources of carbon late in the season reflected the simultaneous decline in river runoff and increase in aquatic productivity as the growing season progressed. However, low air temperatures and protracted snowmelt and ponding in the deeply incised channel of one river in 2003 led to greater solute accumulation in runoff that was discernable in hydrochemical profiles of that lake, even though runoff was greater in 2004. Notwithstanding, calculated nutrient fluxes were greater during the higher-flow year (2004), but mixing was impeded by underflow conditions in the lakes. Despite these differences, connections between river and lake water chemistry appeared weak even with marked seasonal changes in the volume of runoff. Our results highlight the interconnection between site-specific features and hydroclimatic factors like snowmelt and lake ice conditions in influencing limnological conditions and suggest that similar systems may respond differently to the same hydroclimatic conditions. (Au)

F, E, J, H, I
Atmospheric temperature; Biological productivity; Carbon; Chemical properties; Chlorophyll; Climate change; Electrical properties; Fresh-water biology; Growing season; Hydrography; Hydrology; Lake ice; Lakes; Metals; Nitrogen; Phosphorus; Plant nutrition; River discharges; Rivers; Runoff; Seasonal variations; Size; Snowmelt; Stream flow; Suspended solids; Temperature; Water pH; Watersheds

G0813
Bounty, Cape, region, Nunavut


Demography of two lemming species on Bylot Island, Nunavut, Canada   /   Gruyer, N.   Gauthier, G.   Berteaux, D.
(Polar biology, v. 33, no. 6, June 2010, p. 725-736, ill.)
(PCSP/PPCP contribution, no. 048-09)
References.
ASTIS record 74052.
Languages: English
Web: doi:10.1007/s00300-009-0746-7
Libraries: ACU

Lemmings play a key role in the tundra food web and their widely reported cyclic oscillations in abundance may have a strong effect on other components of the ecosystem. We documented seasonal and annual variations in population density, reproductive activity, survival, and body mass of two sympatric species, the brown (Lemmus trimucronatus) and collared lemmings (Dicrostonyx groenlandicus), over a 2-year period on Bylot Island, Nunavut, Canada. We live trapped and marked lemmings on two grids throughout the summer and we estimated demographic parameters using three different capture-recapture methods. All three methods are based on robust estimators and they yielded similar population density estimates. The density of brown lemmings declined markedly between the 2 years whereas that of collared lemmings was relatively constant. For brown lemmings, 2004 was a peak year in their cycle and 2005 a decline phase. Density of brown lemmings also decreased during the summer, but not that of collared lemmings. The recruitment of juvenile brown lemmings in the population increased during the summer and was higher in the peak year than in the year after, but no change was detected in collared lemmings. Survival rates of both species tended to be lower during the peak year than in the following year and body mass of brown lemmings was higher in the peak year than in the following year. We conclude that both changes in adult survival and juvenile recruitment occur during the population decline of brown lemmings. (Au)

I, J
Animal distribution; Animal ecology; Animal growth; Animal live-capture; Animal mortality; Animal population; Animal reproduction; Animal tagging; Lemmings; Mathematical models; Meadows; Seasonal variations; Temporal variations; Tundra ecology; Wildlife habitat

G0813
Bylot Island, Nunavut


Climate, trophic interactions, density dependence and carry-over effects on the population productivity of a migratory Arctic herbivorous bird   /   Morrissette, M.   Bêty, J.   Gauthier, G.   Reed, A.   Lefebvre, J.
(Oikos, v.119, no. 7, July 2010, p.1181-1191, ill., map)
(PCSP/PPCP contribution, no. 049-09)
References.
ASTIS record 70399.
Languages: English
Web: doi:10.1111/j.1600-0706.2009.18079.x
Libraries: ACU

Several driving forces can affect recruitment rates in bird populations. However, our understanding of climate-induced effects or bottom–up vs top–down biological processes on breeding productivity typically comes from small-scale studies, and their relative importance is rarely investigated at the population level. Using a 31-year time series, we examined the effects of selected environmental parameters on the annual productivity of a key Arctic herbivore, the greater snow goose, Anser caerulescens atlanticus. We determined the extent to which breeding productivity, defined as the percentage of juveniles in the fall population, was affected by 1) climatic conditions, 2) fluctuations in predation pressure caused by small rodent oscillations, and 3) population size. Moreover, we took advantage of an unplanned large-scale manipulation (i.e. management action) to examine the potential non-lethal carry-over effects caused by disturbance on spring staging sites. The most parsimonious model explained 66% of the annual variation in goose productivity. The spring North Atlantic Oscillation and Arctic snow depth were the primary climatic parameters inversely affecting the production of juveniles, likely through bottom–up processes. Indirect trophic interactions generated by fluctuations in lemming abundance explained 18% of the variation in goose productivity (positive relationship). Mean temperature during brood-rearing and disturbance on staging sites (carry-over effects) were the other important factors affecting population recruitment. We observed a strong population increase, and found no evidence of density-dependent effects. Spatially restricted studies can identify factors linking environmental parameters to local bird reproduction but if these factors do not act synchronously over the species range, they may fail to identify the relative importance of mechanisms driving large-scale population dynamics. (Au)

I, E, J, F, N
Animal food; Animal health; Animal live-capture; Animal migration; Animal mortality; Animal population; Animal reproduction; Atmospheric temperature; Bioclimatology; Bird nesting; Climate change; Environmental impacts; Greater Snow Geese; Hunting; Lemmings; Predation; Seasonal variations; Snow; Temporal variations; Trophic levels; Tundra ecology; Wildlife management

G0813, G0826
Baffin Island, Nunavut; Bylot Island, Nunavut; Canadian Arctic Islands; Clyde River region, Nunavut; Ellesmere Island, Nunavut; Québec; Resolute Bay region, Nunavut


Twenty-first century discharge and sediment yield predictions in a small High Arctic watershed   /   Lewis, T.   Lamoureux, S.F.
(Global and planetary change, v. 71, no. 1-2, Mar. 2010, p. 27-41, ill., maps)
(PCSP/PPCP contribution, no. 002-10)
References.
ASTIS record 71844.
Languages: English
Web: doi:10.1016/j.gloplacha.2009.12.006
Libraries: ACU

Discharge and suspended sediment flux are predicted for the 21st century for the 8 km² West River, Cape Bounty, Melville Island in the Canadian High Arctic. Discharge predictions are made using a distributed hydrologic model, and sediment yields are predicted using a rating curve based on monitored relationships between discharge and suspended sediment concentration. Models were forced using statistically downscaled air temperature and precipitation from the A1b and A2 scenarios from the global climate model CGCM3. Under the A2 scenario, total seasonal runoff is expected to double by 2100, daily maximum discharge rates will double, and the melt season will increase in length by 30 days, mostly in autumn. Sediment yield increases will be much more extreme, and are expected to increase by 100 to 600%, but these are almost certainly minimum estimates. Variability between and within global climate models is assessed for the grid cell closest to Cape Bounty, and variability within CGCM3 is assessed by examining data from five of its runs. Intra-model variability is relatively small, but inter-model variability is large. The impact of this variability is minimized, and the applicability of results is broadened by assessing relationships between weather variables, hydrologic variables, and sediment yield for multiple model runs. (Au)

F, B, E
Atmospheric temperature; Climate change; Floods; Forecasting; Hydrology; Mathematical models; Precipitation (Meteorology); River discharges; Rivers; Runoff; Sediment transport; Snowmelt; Suspended solids; Temporal variations; Watersheds; Weather stations

G0813
Bounty, Cape, region, Nunavut


Significantly warmer Arctic surface temperatures during the Pliocene indicated by multiple independent proxies   /   Ballantyne, A.P.   Greenwood, D.R.   Sinninghe Damsté, J.S.   Csank, A.Z.   Eberle, J.J.   Rybczynski, N.
(Geology, v. 38, no. 7, July 2010, p. 603-606, ill.)
(PCSP/PPCP contribution, no. 003-10)
Appendix.
References.
ASTIS record 70701.
Languages: English
Web: http://geology.geoscienceworld.org/cgi/reprint/38/7/603
Web: doi:10.1130/G30815.1
Libraries: ACU

Temperatures in the Arctic have increased by an astounding 1° C in response to anthropogenic forcing over the past 20 years and are expected to rise further in the coming decades. The Pliocene (2.6-5.3 Ma) is of particular interest as an analog for future warming because global temperatures were significantly warmer than today for a sustained period of time, with continental configurations similar to present. Here, we estimate mean annual temperature (MAT) based upon three independent proxies from an early Pliocene peat deposit in the Canadian High Arctic. Our proxies, including oxygen isotopes and annual ring widths (MAT = -0.5 ± 1.9° C), coexistence of paleovegetation (MAT = -0.4 ± 4.1° C), and bacterial tetraether composition in paleosols (MAT = -0.6 ± 5.0° C), yield estimates that are statistically indistinguishable. The consensus among these proxies suggests that Arctic temperatures were ~19° C warmer during the Pliocene than at present, while atmospheric CO2 concentrations were ~390 ppmv. These elevated Arctic Pliocene temperatures result in a greatly reduced and asymmetrical latitudinal temperature gradient that is probably the result of increased poleward heat transport and decreased albedo. These results indicate that Arctic temperatures may be exceedingly sensitive to anthropogenic CO2 emissions. ... Introduction: Fossil tetraether lipids derived from soil bacteria, oxygen isotope ratios (delta18O) and annual ring widths in fossil wood, as well as the composition of paleovegetation from the Beaver Pond site on Ellesmere Island (78 N, 82 W), ... were used to derive independent paleotemperature estimates. ... (Au)

B, C, H, E, I
Albedo; Atmospheric chemistry; Atmospheric temperature; Bacteria; Carbon dioxide; Climate change; Heat transmission; Mosses; Oxygen-18; Palaeobotany; Palaeoclimatology; Palaeopedology; Peat; Pliocene epoch; Soil microorganisms

G0813
Ellesmere Island, Nunavut


The chemical development of a hypersaline coastal basin in the High Arctic   /   Dugan, H.A.   Lamoureux, S.F.
(Limnology and oceanography, v. 56, no. 2, Mar. 2011, p. 495-507, ill., maps)
(PCSP/PPCP contribution, no. 004-10)
References.
ASTIS record 74418.
Languages: English
Web: http://www.aslo.org/lo/pdf/vol_56/issue_2/0495.pdf
Web: doi:10.4319/lo.2011.56.2.0495
Libraries: ACU

We investigated a hypersaline, seasonally isolated marine basin (SIMB) in the Canadian High Arctic to elucidate the role of brine rejection, tidal forcing, and groundwater input over the formation of hypersalinity. Analyses of physical parameters and seasonal sampling of ionic and isotopic composition were carried out on a coastal basin near Shellabear Point, Melville Island, Northwest Territories (75°N, 113°W). Observations reveal daily and seasonal variability in the water column due to a seasonal tidal connection during the ice-free season, which lasts substantially longer than the period of freshwater inflow from the catchment. An ice formation model of the volume of brine rejected from surface ice formed from marine water indicates that rapid saline enrichment of the basin due to ice formation is possible from tidally replenished marine water, and that the current hypersalinity may have formed in less than a decade. Modeled isotopic composition of brines are consistent with observations and provide an alternative to freshwater isotopic dilution suggested by other workers. A tidal connection is a critical consideration in lake evolution, and many hypersaline polar lakes could have developed their current chemical composition before full marine isolation. By contrast, in some coastal lakes, marine stratification caused by ice shelves before isolation provides a setting for minimal brine formation and subsequent meromictic conditions to develop. Hence, the marine setting at the time of isolation represents a key factor in explaining divergent lake chemical evolution in the High Arctic. (Au)

F, G, D, E, B, J
Bathymetry; Chemical properties; Coast changes; Density; Formation; Hydrology; Ice; Instruments; Lake stratification; Lakes; Mathematical models; Melting; Palaeohydrology; Physical properties; Salinity; Sea water; Seasonal variations; Suspended solids; Tides; Watersheds

G0813, G0812
Bounty, Cape, Nunavut; Bounty, Cape, region, Nunavut; Garrow Lake, Nunavut; Romulus Lake, Nunavut; Shellabear Lake, N.W.T./Nunavut; Sophia Lake, Nunavut; Taconite Inlet region, Nunavut; Tuborg, Lake, Nunavut


Northern nomads : ability for extensive movements in adult arctic foxes   /   Tarroux, A.   Berteaux, D.   Bêty, J.
(Polar biology, v. 33, no. 8, Aug. 2010, p.1021-1026, ill., maps)
(PCSP/PPCP contribution, no. 005-10)
References.
ASTIS record 70409.
Languages: English
Web: doi:10.1007/s00300-010-0780-5
Libraries: ACU

In July 2008 we outfitted reproductively active adult arctic foxes with satellite tracking collars on Bylot Island, Nunavut, Canada and recorded their movements over a complete annual cycle. We present the tracking data from two individuals, one female and one male, who traveled extensively from February to July 2009, covering minimum distances of 4,599 and 2,193 km, respectively. We recorded high and sustained travel rates on both land and sea ice that reached 90 km/day for the female and 88 km/day for the male. Our data confirm that arctic foxes can move extensively and demonstrate sustained travel rates that are 1.5 times those previously measured for the species. Our study is the first presenting detailed year-round satellite tracking of adult arctic foxes and has implications for our understanding of navigational abilities, foraging ecology, trophic interactions with lemming populations, and genetic population structure of arctic foxes. (Au)

I
Animal behaviour; Animal food; Animal live-capture; Animal migration; Animal reproduction; Animal tagging; Arctic foxes; Genetics; Lemmings; Movement; Predation; Radio tracking of animals; Satellite communications; Seasonal variations; Telemetry

G0813, G0815, G09
Admiralty Inlet region, Nunavut; Baffin Bay-Davis Strait; Baffin Island, Nunavut; Bylot Island, Nunavut; Devon Island, Nunavut; Eclipse Sound, Nunavut; Lancaster Sound, Nunavut; Navy Board Inlet, Nunavut; Peel Sound, Nunavut; Pond Inlet, Nunavut; Prince of Wales Island, Nunavut; Prince Regent Inlet, Nunavut; Somerset Island, Nunavut


Autumn snowfall and hydroclimatic variability during the past millennium inferred from the varved sediments of meromictic Lake A, northern Ellesmere Island, Canada   /   Tomkins, J.D.   Lamoureux, S.F.   Antoniades, D.   Vincent, W.F.
(Quaternary research, v. 74, no. 2, Sept. 2010, p. 188-198, ill., maps)
(PCSP/PPCP contribution, no. 006-10)
References.
ASTIS record 71783.
Languages: English
Web: doi:10.1016/j.yqres.2010.06.005
Libraries: ACU

We examined the hydroclimatic signal in a record of annual lamina (varve) thickness from High Arctic Lake A, Ellesmere Island (83 00 N, 75 30 W). In this unglacierized catchment, nival melt is the dominant source for meltwater and transport of sediment to the lake, and autumn snowfall is highly influential on varve thickness through the amount of snow available for melt in the following year. For the period during which climatic data are available, varve thickness in Lake A was significantly correlated (r=0.50, p<0.01) with the cumulative snowfall from August to October (ASO) mean daily temperature (r=0.39, p <0.01) at Alert, Nunavut (175 km est). The varve thickness record, interpreted as a proxy record of ASO snowfall and, by extension, ASO temperature, indicated above-mean conditions during five periods of the past millennium, including most of the 20th century. These results corresponded well to other available high-resolution proxy climate records from the region, with some discrepancies prior to AD 1500 and during the period AD 1700-1900. (Au)

B, F, E
Biological productivity; Bottom sediments; Cores; Fresh-water biology; Ice cover; Lake stratification; Lakes; Palaeoclimatology; Palaeontology; Recent epoch; Refugia; River discharges; Sea water; Sediment transport; Sedimentation; Sediments (Geology); Snow; Snow cover; Snowmelt; Suspended solids; Thickness; Water masses

G0813
Marvin Peninsula, Nunavut


Metagenomic profiling of Arctic microbial mat communities as nutrient scavenging and recycling systems   /   Varin, T.   Lovejoy, C.   Jungblut, A.D.   Vincent, W.F.   Corbeil, J.
(Limnology and oceanography, v. 55, no. 5, Sept. 2010, p.1901-1911, ill., maps)
(PCSP/PPCP contribution, no. 008-10)
References.
ASTIS record 71782.
Languages: English
Web: doi:10.4319/lo.2010.55.5.1901
Libraries: ACU

By way of metagenomics and high-throughput pyrosequencing, we addressed the hypothesis that cyanobacterial mats in polar aquatic ecosystems maintain a nutrient-rich microenvironment via decomposition and scavenging processes. Analysis of more than 592,554 genomic deoxyribonucleic acid (DNA) reads (total of 11.5 million base pairs) showed that the ribosomal and protein-coding genes of two High Arctic ice-shelf mat communities were dominated by Proteobacteria, not Cyanobacteria, which implies a broad range of bacterial decomposition and nutrient recycling processes in addition to phototrophy. Principal component analysis of genes for light-, nitrogen-, and phosphorus-related processes provided evidence of partitioning of mat function among taxonomically different constituents of the mat consortia. Viruses were also present (notably Alpha-, Beta-, Gammaproteobacteria phages and cyanophages), which likely contribute to cellular lysis and recycling, as well as other Bacteria, Archaea, and microbial eukaryotes. Nitrogen-related genes were dominated by ammonium-assimilation systems, implying that the microbial mats are sites of intense mineralization, but not N-oxidation, since nitrification genes were absent. Nutrient scavenging systems were detected, including genes for transport proteins and enzymes for converting larger molecules into more readily assimilated inorganic forms (allantoin degradation, cyanate hydrolysis, exophosphatases, phosphonatases). Metagenomic profiling results underscore the rich diversity of microbial life even in extreme polar habitats, and the capability of mat consortia to retain and recycle nutrients in the benthic microenvironment. (Au)

H, D, F, G, J
Adaptation (Biology); Ammonium; Benthos; Biodegradation; Biological productivity; Biomass; Breakup; Chlorophyll; Climate change; Cyanophyceae; Electrical properties; Fresh-water ecology; Geochemistry; Ice shelves; Lake stratification; Light; Marine ecology; Microbial ecology; Nitrogen; Phosphorus; Phytoplankton; Plant nutrition; Primary production (Biology); Puddles; Temperature; Water pH

G0813, G0815
Markham Fiord, Nunavut; Ward Hunt Ice Shelf, Nunavut


Chironomid assemblages from seabird-affected High Arctic ponds   /   Michelutti, N.   Mallory, M.L.   Blais, J.M.   Douglas, M.S.V.   Smol, J.P.
(Polar biology, v. 34, no. 6, June 2011, p. 799-812, ill., maps)
(PCSP/PPCP contribution, no. 009-10)
References.
Electronic supplementary material is available from the online version of this article.
ASTIS record 79107.
Languages: English
Web: doi:10.1007/s00300-010-0934-5
Libraries: ACU

Seabirds can shunt nutrients and contaminants from marine to terrestrial ecosystems by forming dense breeding colonies and releasing wastes to these sites. A large colony of seabirds at Cape Vera (Devon Island, High Arctic Canada) has resulted in eutrophic conditions and potentially toxic concentrations of sedimentary metals in several freshwater ponds that drain their nesting sites. Here, we investigated the effects of elevated nutrient and sedimentary metal concentrations on the distribution of subfossil chironomids in surface sediments from 21 ponds that span a gradient of seabird influence. Although many ponds registered high nutrient concentrations (e.g., mean TP = 45µg/l), eutrophic taxa typical of temperate waters were not common, with most assemblages being dominated by morphotypes of Psectrocladius and Tanytarsina, as well as Corynoneura arctica-type, and Metriocnemus hygropetricus-type. Although the ponds within and outside the area influenced by seabirds contained largely similar taxa, variations did exist in the relative abundances of the different species. Lakewater pH was the only measured environmental variable that explained statistically significant amounts of variation in the chironomid assemblages. Although direct effects of pH on chironomids cannot be ruled out, pH is likely tracking production-related changes driven by limnetic dissolved inorganic carbon dynamics. Sediment cores collected from seabird-affected and seabird-free ponds showed a greater number of chironomid taxa and higher head capsule abundances in the pond receiving seabird inputs. Chironomid assemblages in both cores recorded increased abundances in recent decades, likely in response to warmer conditions and lengthened growing seasons. (Au)

I, F, J, B, H, E
Animal taxonomy; Animal waste products; Bioaccumulation; Bioclimatology; Biomagnification; Bird nesting; Bottom sediments; Carbon; Chemical properties; Chironomidae; Climate change; Environmental impacts; Eutrophic lakes; Fulmars; Hydrology; Metals; Mosses; Nitrogen; Palaeoecology; Palaeontology; Phosphorus; Sea birds; Trophic levels; Tundra ponds; Water pH; Water pollution

G0813
Vera, Cape, Nunavut


Sensitivity of active-layer development to winter conditions north of treeline, Mackenzie Delta area, western Arctic coast   /   Burn, C.R.   Zhang, Y.
In: GEO2010 : 63rd Canadian Geotechnical Conference & 6th Canadian Permafrost Conference = 63e conférence géotechnique canadienne et 6e conférence canadienne sur le pergélisol, [Sept. 12-16, 2010]. - [Richmond, B.C.] : Canadian Geotechnical Society, 2010, p.1458-1465, ill., maps
(PCSP/PPCP contribution, no. 011-10)
References.
Proceedings distributed on a USB flash drive entitled: GEO2010 in the New West, Calgary, Alberta.
ASTIS record 72961.
Languages: English
Web: http://pubs.aina.ucalgary.ca/cpc/CPC6-1458.pdf
Libraries: OONL

A simulation of the ground thermal regime in undisturbed tundra near the western Arctic coast has been validated by reproducing changes in ground temperatures between 1970 and 2009 to 53-m depth. The model has been used to determine the response of ground temperatures and active-layer thickness to potential climate warming up to 2100. The majority of the warming is in autumn and winter. Permafrost is sustained under this climate scenario, but a considerable increase in active-layer thickness may occur, because ground cooling is reduced in winter. (Au)

C, F, E, J, H
Active layer; Atmospheric temperature; Boreholes; Climate change; Effects of climate on permafrost; Mathematical models; Measurement; Permafrost; Plant distribution; Seasonal variations; Snow; Soil temperature; Soils; Taiga ecology; Temporal variations; Thermal properties; Thermal regimes; Thickness; Treeline; Tundra ecology

G0812, G0811
Herschel Island, Yukon; Illisarvik Lake region, N.W.T.; Illisarvik Lake, N.W.T.; Mackenzie Delta, N.W.T.; Richards Island, N.W.T.; Tuktoyaktuk region, N.W.T.


Controls on near-surface temperatures across tree line in the Mackenzie Delta area, Northwest Territories, 2004-2009   /   Palmer, M.J.   Kokelj, S.V.   Burn, C.R.
In: GEO2010 : 63rd Canadian Geotechnical Conference & 6th Canadian Permafrost Conference = 63e conférence géotechnique canadienne et 6e conférence canadienne sur le pergélisol, [Sept. 12-16, 2010]. - [Richmond, B.C.] : Canadian Geotechnical Society, 2010, p.1480-1487, ill., map
(PCSP/PPCP contribution, no. 012-10)
References.
Proceedings distributed on a USB flash drive entitled: GEO2010 in the New West, Calgary, Alberta.
No French abstract available for this paper.
ASTIS record 72960.
Languages: English
Web: http://pubs.aina.ucalgary.ca/cpc/CPC6-1480.pdf
Libraries: OONL

Air and near-surface ground temperatures were recorded between 2004 and 2009, and properties of the snow cover were measured annually in late winter at eight sites along a 130-km transect across the forest-tundra transition in the uplands east of the Mackenzie Delta, NWT, to investigate the relations between these variables along the ecological gradient. Late winter snow depths decreased along the tree-line transect in association with changes in vegetation cover between sites. A gradient in near-surface ground temperature was observed along the transect, as annual near-surface ground temperatures decreased northward. The ground temperature gradient was steepest (0.1 to 0.3°C/km) between 20 and 30 km from Inuvik. The steep gradient in near-surface ground temperature was associated with large differences in late-winter snow depth between the sites. (Au)

C, F, E, J, H
Atmospheric temperature; Climate change; Effects of climate on permafrost; Microclimatology; Permafrost; Plant cover; Plant distribution; Snow cover; Soil temperature; Spatial distribution; Temporal variations; Thermal regimes; Thickness; Treeline

G0812
Mackenzie Delta, N.W.T.


Permafrost conditions near shorelines of oriented lakes in Old Crow Flats, Yukon Territory   /   Roy-Léveillée, P.   Burn, C.R.
In: GEO2010 : 63rd Canadian Geotechnical Conference & 6th Canadian Permafrost Conference = 63e conférence géotechnique canadienne et 6e conférence canadienne sur le pergélisol, [Sept. 12-16, 2010]. - [Richmond, B.C.] : Canadian Geotechnical Society, 2010, p.1509-1516, ill., maps
(PCSP/PPCP contribution, no. 013-10)
References.
Proceedings distributed on a USB flash drive entitled: GEO2010 in the New West, Calgary, Alberta.
ASTIS record 72958.
Languages: English
Web: http://pubs.aina.ucalgary.ca/cpc/CPC6-1509.pdf
Libraries: OONL

Old Crow Flats is a 4300 km² plain in the continuous permafrost of Northern Yukon. It contains over 2500 thermokarst lakes, many of which have rectilinear shorelines and tend to be oriented either NE-SW or NW-SE. Previous explanations of the shape and orientation of the lakes focussed on the underlying geological structure and the propagation of faults through the sediments to cause the alignment of the lakeshores. Permafrost conditions and shore erosion mechanisms observed at forested and tundra sites suggest that wind and patterns of ice-wedge development may be contributing to the occurrence of rectilinear shorelines in the open tundra of Old Crow Flats. (Au)

C, F, A, B, E
Beach erosion; Bottom sediments; Faults (Geology); Geology; Ice wedges; Lake waves; Lakes; Permafrost; Sedimentation; Shorelines; Winds

G0812
Old Crow Flats, Yukon


Spatial variation in the thermal regime of Mackenzie Delta lakes and channels   /   Ensom, T.P.   Burn, C.R.   Kokelj, S.V.
In: GEO2010 : 63rd Canadian Geotechnical Conference & 6th Canadian Permafrost Conference = 63e conférence géotechnique canadienne et 6e conférence canadienne sur le pergélisol, [Sept. 12-16, 2010]. - [Richmond, B.C.] : Canadian Geotechnical Society, 2010, p.1488-1493, ill., maps
(PCSP/PPCP contribution, no. 014-10)
References.
Proceedings distributed on a USB flash drive entitled: GEO2010 in the New West, Calgary, Alberta.
ASTIS record 72959.
Languages: English
Web: http://pubs.aina.ucalgary.ca/cpc/CPC6-1488.pdf
Libraries: OONL

The Mackenzie Delta, Northwest Territories, is an alluvial plain with approximately 40% aerial coverage of lakes and distributary channels. Tundra and taiga ecozones create two distinct terrestrial permafrost environments within the delta. Continuous temperature measurements made in 27 delta water bodies during 2009 indicate little spatial variation in the summer thermal regime of channels and lakes. Low spatial variation is also expected on an annual basis. (Au)

C, F, A, B, E
Beach erosion; Bottom sediments; Lakes; Measurement; Permafrost; Seasonal variations; Shorelines; Soil temperature; Spatial distribution; Temperature; Thermal regimes

G0812
Mackenzie Delta, N.W.T.


Ground temperature variation with snow, Kendall Island Bird Sanctuary, outer Mackenzie Delta, Northwest Territories   /   Morse, P.D.   Burn, C.R.   Kokelj, S.V.
In: GEO2010 : 63rd Canadian Geotechnical Conference & 6th Canadian Permafrost Conference = 63e conférence géotechnique canadienne et 6e conférence canadienne sur le pergélisol, [Sept. 12-16, 2010]. - [Richmond, B.C.] : Canadian Geotechnical Society, 2010, p.1441-1449, ill., maps
(PCSP/PPCP contribution, no. 015-10)
References.
Proceedings distributed on a USB flash drive entitled: GEO2010 in the New West, Calgary, Alberta.
ASTIS record 72957.
Languages: English
Web: http://pubs.aina.ucalgary.ca/cpc/CPC6-1441.pdf
Libraries: OONL

Near-surface ground temperatures in the Kendall Island Bird Sanctuary (KIBS), investigated from 2005 to 2009, were principally influenced by snow depth. The snow pack evolves primarily by wind redistribution and follows the same spatial pattern annually. Snow depth was dominantly influenced by topography in uplands and vegetation height in the alluvial plain. Ground temperatures and active-layer thicknesses, and their ranges, were greater at the alluvial plain than at the upland. Considerable snow during active-layer freezing significantly prolonged the zero curtain. (Au)

C, F, J, H
Active layer; Permafrost; Plant distribution; Seasonal variations; Snow cover; Snowfall; Soil freezing; Soil temperature; Spatial distribution; Thermal regimes; Thickness; Topography

G0812
Kendall Island Migratory Bird Sanctuary, N.W.T.


Stable isotope analysis : modelling lipid normalization for muscle and eggs from Arctic mammals and birds   /   Ehrich, D.   Tarroux, A.   Stien, J.   Lecomte, N.   Killengreen, S.   Berteaux, D.   Yoccoz, N.G.
(Methods in ecology and evolution, v. 2, no. 1, Jan. 2011, p. 66-76, ill.)
(PCSP/PPCP contribution, no. 017-10)
References.
Supporting material available online.
ASTIS record 74012.
Languages: English
Web: doi:10.1111/j.2041-210X.2010.00047.x
Libraries: ACU

SUMMARY. 1. Lipids are more depleted in 13C than proteins. Variable lipid contents in tissues affect therefore the measurements of stable carbon isotope ratios. Model based (also called mathematical) normalization has been suggested to correct delta 13C values using the ratio of carbon to nitrogen (C/N) as a proxy for lipid content. This approach has not been thoroughly validated for terrestrial animals and it is not clear to what extent it is generally applicable or species/tissue specific. 2. Ratios of stable carbon isotopes (delta 13C) were obtained for muscle samples of 22 mainly terrestrial arctic mammal and bird species and for egg samples of 32 bird species from nine sites in the circumpolar Arctic. We used linear and nonlinear equations to model the difference in delta 13C between samples from which lipids had been extracted chemically and bulk tissue samples. Models were compared on the basis of a model selection criterion (AIC) and of prediction error as estimated by cross-validation. 3. For muscle samples, a linear and a nonlinear equation performed equally well. The observed values were also well predicted by a previously published general equation for aquatic organisms. For egg samples, a nonlinear equation fitted separately to waterfowl and non waterfowl bird species fitted the data best. Prediction errors were, however, larger than for muscle samples. 4. The generality of the inferred normalization equations was assessed by applying them to a second data set from a similar ecosystem, but produced in the frame of another study. The predicted lean delta 13C values were within 0·5‰ of the observed values for 73% of the muscle samples, but only for 27% of the egg samples. 5. Based on our results, we recommend model based normalization of delta 13C values as an economic way to deal with varying lipid contents in muscle samples of mammals and birds. For egg samples, on the contrary, model based predictions had large errors. Therefore, we recommend chemical lipid extraction in order to estimate lipid-free delta 13C values for egg content. (Au)

I, J
Biological sampling; Bird nesting; Birds; Carbon; Isotopes; Lipids; Mammals; Mathematical models; Nitrogen; Proteins; Trophic levels; Waterfowl

G0813, G14, G13
Bylot Island, Nunavut; Dolgiy, Ostrov, (69 16 10 N, 59 04 32 E), Russian Federation; Khanty-Mansiyskiy Natsional'nyy Okrug, Russian Federation; Lena, Reka, Russian Federation; Nenetskiy Avtonomnyy Okrug, Russian Federation; Svalbard; Varangerhalvoya, Norway; Vrangelya, Ostrov, Russian Federation


The thermal state of permafrost in Canada - results from the International Polar Year   /   Smith, S.L.   Lewkowicz, A.G.   Burn, C.R.   Allard, M.   Throop, J.
In: GEO2010 : 63rd Canadian Geotechnical Conference & 6th Canadian Permafrost Conference = 63e conférence géotechnique canadienne et 6e conférence canadienne sur le pergélisol, [Sept. 12-16, 2010]. - [Richmond, B.C.] : Canadian Geotechnical Society, 2010, p.1214-1221, ill., maps
(PCSP/PPCP contribution, no. 018-10)
References.
Proceedings distributed on a USB flash drive entitled: GEO2010 in the New West, Calgary, Alberta.
PCSSP contribution number 20100056.
ASTIS record 72662.
Languages: English
Web: http://pubs.aina.ucalgary.ca/cpc/CPC6-1214.pdf
Libraries: OONL

A snapshot of permafrost thermal state in northern Canada during the International Polar Year was developed with ground temperature measurements from about 170 boreholes. The measurements span a wide range of ecoclimate and geological conditions and are at various elevations. Ground temperatures within the discontinuous permafrost zone are generally above -2°C and range to as low as -15°C in the continuous zone. Permafrost temperatures have generally increased across northern Canada for the past several decades, with greater warming rates occurring north of tree line. Consequently the spatial diversity of permafrost thermal conditions is decreasing over time. (Au)

C, E, J
Active layer; Boreholes; Effects monitoring; Effects of climate on permafrost; Measurement; Permafrost; Soil temperature; Spatial distribution; Temporal variations; Thermal regimes

G081
Canadian Arctic


Forecasting ecological and evolutionary strategies to global change : an example from habitat selection by lemmings   /   Morris, D.W.   Moore, D.E.   Ale, S.B.   Dupuch, A.
(Global change biology, v. 17, no. 3, Mar. 2011, p.1266-1276, ill.)
(PCSP/PPCP contribution, no. 019-10)
Appendix (supporting information).
References.
ASTIS record 75146.
Languages: English
Web: doi:10.1111/j.1365-2486.2010.02305.x
Libraries: ACU

Ecologists and evolutionary biologists must develop theories that can predict the consequences of global warming and other impacts on Earth's biota. Theories of adaptive habitat selection are particularly promising because they link distribution and density with fitness. The evolutionarily stable strategy that emerges from adaptive habitat choice is given by the system's habitat isodar, the graph of densities in pairs of habitats such that the expectation of fitness is the same in each. We illustrate how isodars can be converted into adaptive landscapes of habitat selection that display the density- and frequency-dependent fitness of competing strategies of habitat use. The adaptive landscape varies with the abundance of habitats and can thus be used to predict future adaptive distributions of individuals under competing scenarios of habitat change. Application of the theory to three species of Arctic rodents living on Herschel Island in the Beaufort Sea predicts changes in selection gradients as xeric upland increases in frequency with global warming. Selection gradients will become more shallow for brown lemming (Lemmus trimucronatus) and tundra vole (Microtus oeconomus) strategies that preferentially exploit mesic habitat. Climate change will cause selection gradients for the alternative strategy of using mostly xeric habitat to become much steeper. Meanwhile, the adaptive landscape for collared lemmings (Dicrostonyx groenlandicus), which specialize on xeric Dryas-covered upland, will become increasingly convex. Changes in the adaptive landscapes thus predict expanding niches for Lemmus and Microtus, and a narrower niche for Dicrostonyx. The ability to draw adaptive landscapes from current patterns of distribution represents one of the few methods available to forecast the consequences of climate change on the future distribution and evolution of affected species. (Au)

I, J, H, A, E, C
Adaptation (Biology); Animal behaviour; Animal distribution; Animal live-capture; Animal population; Climate change; Effects of climate on plants; Environmental impacts; Evolution (Biology); Forecasting; Frost boils; Hummocks; Lemmings; Mathematical models; Meadows; Plant cover; Plant distribution; Plants (Biology); Sedges; Soil moisture; Temporal variations; Tundra ecology; Voles; Wildlife habitat; Wildlife management

G0811
Herschel Island, Yukon


Spatial and temporal variations in ice motion, Belcher Glacier, Devon Island, Nunavut, Canada   /   Van Wychen, W.   Copland, L. [Supervisor]   Gray, L. [Co-Supervisor]   Sawada, M. [Co-Supervisor]
Ottawa : University of Ottawa, 2010.
167 p. : ill., maps ; 28 cm.
(Proquest Dissertations & Theses publication, no. MR69027)
(PCSP/PPCP contribution, no. 020-10)
ISBN 9780494690277
Thesis (M.Sc.) - University of Ottawa, Ottawa, Ont., 2010.
Indexed from a PDF file acquired from ProQuest Dissertations & Theses.
References.
ASTIS record 75149.
Languages: English
Libraries: OONL

This study presents surface ice motion patterns across Devon Ice Cap, with a particular focus on the Belcher Glacier drainage basin. Between summer 2007 and summer 2009, continuous differential GPS (dGPS) measurements were made to determine the motion at points along the centerline of the Belcher Glacier with ~cm accuracy. In summer 2008, marker stakes were set out on all accessible tributaries in the Belcher basin, with each stake being surveyed with dGPS several times throughout the season. Using synthetic aperture radar (SAR) speckle tracking techniques new velocity maps were produced of seasonal changes in ice motion for the Belcher Glacier. These were validated against the field dGPS results. Ground penetrating radar (GPR) was used to determine the ice depths of each tributary basin in the Belcher Glacier study region. These ice depths are combined with velocities derived from the speckle tracking results to create flux gates which allow for estimates of total ice discharge for the Belcher basin. These volume estimates can be used to improve mass loss estimates for future modeling of Devon Ice Cap. The velocity results are compared to the work of Burgess et al (2005), who provided flow dynamics and mass loss from the Devon Ice Cap and Belcher Glacier systems using interferometry and speckle tracking of ERS 1/2 data from the mid-1990s and Radarsat-1 data from 2000. These comparisons reveal higher ice velocities on a large glacier in the southeast part of the ice cap (Southeast2 Glacier), which agrees with recent thickening of the stagnant ice into which the glacier drains. (Au)

F, E
Density; Drainage; Effects of climate on ice; Flow; Geographical positioning systems; Glacial melt waters; Glaciers; Ground penetrating radar; Hydrology; Ice caps; Mass balance; Mathematical models; Measurement; Radar; Remote sensing; SAR; Satellite photography; Sea ice; Seasonal variations; Snow surveys; Spatial distribution; Temporal variations; Theses; Thickness; Velocity

G0813
Belcher Glacier, Nunavut; Devon Ice Cap, Nunavut


Evidence for the enhanced lability of dissolved organic matter following permafrost slope disturbance in the Canadian High Arctic   /   Woods, G.C.   Simpson, M.J.   Pautler, B.G.   Lamoureux, S.F.   Lefrenière, M.J.   Simpson, A.J.
(Geochimica et cosmochimica acta, v. 75, no. 22, 15 Nov. 2011, p.7226-7241, ill., maps)
(PCSP/PPCP contribution, no. 025-10)
References.
ASTIS record 74817.
Languages: English
Web: doi:10.1016/j.gca.2011.08.013
Libraries: ACU

Arctic landscapes are believed to be highly sensitive to climate change and accelerated disturbance of permafrost is expected to significantly impact the rate of carbon cycling. While half the global soil organic matter (SOM) is estimated to reside in Arctic soils, projected warmer temperatures and permafrost disturbance will release much of this SOM into waterways in the form of dissolved organic matter (DOM). The spring thaw and subsequent flushing of soils releases the highest contributions of DOM annually but has historically been undersampled due to the difficulties of sampling during this period. In this study, passive samplers were placed throughout paired High Arctic watersheds during the duration of the 2008 spring flush in Nunavut, Canada. The watersheds are very similar with the exception of widespread active layer detachments (ALDs) that occurred within one of the catchments during a period of elevated temperatures in the summer of 2007. DOM samples were analyzed for structural and spectral characteristics via nuclear magnetic resonance (NMR) and fluorescence spectroscopy as well as vulnerability to degradation with simulated solar exposure. Lignin-derived phenols were further assessed utilizing copper(II) oxide (CuO) oxidation and gas chromatography/mass spectrometry (GC/MS). The samples were found to have very low dissolved lignin phenol content (~0.07% of DOC) and appear to originate from primarily non-woody angiosperm vegetation. The acid/aldehyde ratios for dissolved vanillyl phenols were found to be high (up to 3.6), indicating the presence of highly oxidized lignin. Differences between DOM released from the ALD vs. the undisturbed watershed suggest that these shallow detachment slides have significantly impacted the quality of Arctic DOM. Although material released from the disturbed catchment was found to be highly oxidized, DOM in the lake into which this catchment drained had chemical characteristics indicating high contributions from microbial and/or primary productivity. The resulting pool of dissolved carbon within the lake appears to be more biologically- and photochemically-labile than material from the undisturbed system. These disturbances may have implications for projected climate warming; sustained elevated temperatures would likely perpetuate widespread ALDs and further affect carbon cycling in this environment. (Au)

C, A, F, B, E, J, H
Active layer; Amino acids; Carbon cycling; Chemical properties; Climate change; Dissolved organic carbon; Drainage; Environmental impacts; Erosion; Fluorometry; Geochemistry; Geomorphology; Hydrology; Lakes; Measurement; Microbial ecology; Permafrost; Primary production (Biology); Runoff; Sediment transport; Slopes; Snowmelt; Soils; Solar radiation; Spectroscopy; Stream erosion; Stream flow; Thaw flow slides; Thawing; Thickness; Watersheds

G0813
Bounty, Cape, region, Nunavut


Cultural eutrophication, anoxia, and ecosystem recovery in Meretta Lake, High Arctic Canada   /   Antoniades, D.   Michelutti, N.   Quinlan, R.   Blais, J.M.   Bonilla, S.   Douglas, M.S.V.   Pienitz, R.   Smol, J.P.   Vincent, W.F.
(Limnology and oceanography, v. 56, no. 2, Mar. 2011, p. 639-650, ill., maps)
(PCSP/PPCP contribution, no. 026-10)
References.
ASTIS record 73176.
Languages: English
Web: doi:10.4319/lo.2011.56.2.0639
Libraries: ACU

We studied the effects of four decades of cultural eutrophication on Meretta Lake, in the Canadian High Arctic, through a multiproxy analysis of its sediments, including sedimentary pigments, metal concentrations, stable isotope ratios, chironomids, and diatoms. While Meretta Lake's biota clearly responded to nutrient inputs, the manner in which the changes differed from those expected in temperate lakes underlined the profound effects in Arctic lakes of extended ice and snow cover on light penetration, mixing, and interactions with the atmosphere. Hypolimnetic anoxia developed rapidly in Meretta Lake in response to sewage enrichment and was accompanied by the appearance of photosynthetic sulfur bacteria. Benthic communities responded rapidly to sewage inputs, but phytoplankton biomass did not increase until eutrophication was accompanied by climate warming, further reinforcing the importance of ice cover in controlling biotic processes in high Arctic lakes. With climate-mediated ice cover reductions in Meretta Lake, the response to eutrophication began to more closely resemble temperate processes. Recent trajectories indicate that slightly more than a decade after the cessation of sewage inputs, Meretta Lake is recovering toward pre-enrichment conditions. (Au)

H, I, F, G, E, J, B, M
Benthos; Bottom sediments; Carbon; Chironomidae; Chlorophyll; Climate change; Cores; Diatoms; Environmental impacts; Eutrophic lakes; Fertilizers; Fluorometry; Food chain; Fresh-water biology; Fresh-water ecology; Ice cover; Isotopes; Lake ice; Lake stratification; Lake-atmosphere interaction; Lakes; Light; Mass spectrometry; Metals; Nitrogen; Oxygen; Palaeontology; Phytoplankton; Sewage disposal; Water quality

G0813
Meretta Lake, Nunavut


Effects of loss of perennial lake ice on mixing and phytoplankton dynamics : insights from High Arctic Canada   /   Veillette, J.   Martineau, M.-J.   Antoniades, D.   Sarrazin, D.   Vincent, W.F.
(Annals of glaciology, v. 51, no. 56, Dec. 2010, p. 56-70, ill., maps)
(PCSP/PPCP contribution, no. 027-10)
References.
ASTIS record 73177.
Languages: English
Web: doi:10.3189/172756411795931921
Libraries: ACU

Perennially ice-covered lakes are well known from Antarctica and also occur in the extreme High Arctic. Climate change has many implications for these lakes, including the thinning and disappearance of their perennial ice cover. The goal of this study was to consider the effects of transition to seasonal ice cover by way of limnological observations on a series of meromictic lakes along the northern coastline of Ellesmere Island, Nunavut, Canada. Conductivity-temperature profiles during a rare period of ice-free conditions (August 2008) in these lakes suggested effects of wind-induced mixing of their surface freshwater layers and the onset of entrainment of water at the halocline. Sampling of the mixed layer of one of these meromictic lakes in May and August 2008 revealed a pronounced vertical structure in phytoplankton pigments and species composition, with dominance by cyanobacteria, green algae, chrysophytes, cryptophytes and dinoflagellates, and a conspicuous absence of diatoms. The loss of ice cover resulted in an 80-fold increase in water column irradiance and apparent mixing of the upper water column during a period of higher wind speeds. Zeaxanthin, a pigment found in cyanobacteria, was entirely restricted to the <3 µm cell fraction at all depths and increased by a factor of 2-17, with the greatest increases in the upper halocline region subject to mixing. Consistent with the pigment data, picocyanobacterial populations increased by a factor of 3, with the highest concentration (1.65×10**8 cells/L) in the upper halocline. Chlorophyll a concentrations and the relative importance of phytoplankton groups differed among the four lakes during the open-water period, implying lake-specific differences in phytoplankton community structure under ice-free conditions. (Au)

E, F, H, G, B, I
Algae; Biological sampling; Chlorophyll; Chromatography; Climate change; Effects of climate on ice; Electrical properties; Fluorometry; Fresh-water biology; Fresh-water invertebrates; Ice cover; Lake ice; Lake stratification; Lakes; Optical properties; Palaeontology; Photosynthesis; Phytoplankton; Primary production (Biology); Salinity; Solar radiation; Temperature; Temporal variations; Winds

G0813
Ellesmere Island, Nunavut


Mid to Late Holocene hydroclimatic and geochemical records from the varved sediments of East Lake, Cape Bounty, Canadian High Arctic   /   Cuven, S.   Francus, P.   Lamoureux, S.
(Quaternary science reviews, v. 30, no. 19-20, Sept. 2011, p.2651-2665, ill., maps)
(PCSP/PPCP contribution, no. 028-10)
References.
ASTIS record 74790.
Languages: English
Web: doi:10.1016/j.quascirev.2011.05.019
Libraries: ACU

A long sedimentary sequence from East Lake, Cape Bounty, Melville Island (74°55'N; 109°30'W) contains a 4200 year-long clastic varved record of paleohydrologic variations at high resolution. Sedimentary elemental geochemistry from micro X-ray fluorescence (µ-XRF) and sediment fabric variability reflect changes in sediment sources and lacustrine conditions through time. The sedimentary environment progressed from marine in the mid-Holocene, to estuarian from 2195 BC to 243 AD, to fully lacustrine source after 244 AD. Correlation with local meteorological data indicates that varve thickness (VT) is positively correlated with snow depth on May 1st and negatively correlated with mean Sept-May temperatures. Our paleoclimatic reconstruction from VT series revealed high snow accumulation and warm Sept-May months before 1350 BC, and a period of low snow accumulation and cold Sept-May between 1600-1900 AD that may correspond to the Little Ice Age. The general trends of VT series from Cape Bounty are in phase with the delta 18O series in Agassiz Ice Cap, and in anti-phase with the VT series from Lower Murray Lake in the northeastern of Queen's Elizabeth Islands (QEI). Low mean Arctic temperatures coincide with clusters of high sediment yield events at East, Nicolay and South Sawtooth Lakes, especially during 1600-1750 AD and 1810-1910 AD. The East Lake record also exhibits the signature of the Atlantic Multidecadal Oscillation (AMO) for periods: 600-850 AD, 1400-1550 AD and 1750-1850 AD. (Au)

B, E, F, A
Atmospheric temperature; Bottom sediments; Calcium; Cesium; Clay; Climate change; Cores; Fluorometry; Geochemistry; Geological time; Glacial epoch; Iron; Isotopes; Lake ice; Lakes; Lead; Manganese; Microscopes; Oxygen-18; Palaeoclimatology; Palaeohydrology; Potassium; Radioactive dating; Rain; Recent epoch; Runoff; Sand; Seasonal variations; Sediment transport; Sedimentary structures; Sedimentation; Silicon; Silt; Size; Snow; Snowmelt; Stratigraphy; Temporal variations; Thickness; X-rays; Zirconium

G0813
Bounty, Cape, region, Nunavut; East Lake, Nunavut


Slope hummock development, Fosheim Peninsula, Ellesmere Island, Nunavut, Canada   /   Lewkowicz, A.G.
(Special issue on periglacial processes, landforms, and environments in honor of Link Washburn. Quaternary research, v. 75, no. 2, Mar. 2011, p. 334-346, ill., maps)
(PCSP/PPCP contribution, no. 001-11)
References.
ASTIS record 79118.
Languages: English
Web: doi:10.1016/j.yqres.2010.12.013
Libraries: ACU

Slope hummocks, a type of nonsorted patterned ground, are composed of stratified, organic, silty sand, and develop through the interaction of niveo-eolian deposition, solifluction, slopewash, and vegetation growth. Fields of hummocks show consistent patterns: forms on convex slopes increase in height downslope until the channel is reached, whereas those on convexo-concave slopes increase on the upper convexity but are buried by niveo-eolian deposition downslope of the snowbank remnant. These trends can be reproduced using a simple numerical model based on measured slope and snow depth profiles, sediment concentrations in the snow and solifluction rates. The model indicates that hummocks transit slopes of 20-40 m in about 2-4 ka, a time-frame that is plausible given site emergence, measured rates of solifluction, and published dates for organic horizons within hummocks on northern Ellesmere Island. Sensitivity analyses show that long-term effect of climate warming on hummock heights may differ depending on whether it is accompanied by precipitation increase or decrease. The required combination of two-sided freezing to promote plug-like movement, incomplete vegetation cover and thin snow that enable eolian erosion during winter and spring, and vegetation growth in snow-bed sites to stabilize niveo-eolian deposits may explain why these forms are important regionally but apparently are not present throughout the Arctic. (Au)

C, A, E, J, F
Climate change; Creep; Environmental impacts; Frost action; Hummocks; Mathematical models; Measurement; Nivation; Patterned ground; Plant cover; Sand; Silt; Size; Slopes; Snow; Snowpatches; Soil texture; Stratigraphy; Sublimation; Temporal variations; Thaw flow slides; Thaw settlement; Thawing; Weathering; Wind erosion; Winds

G0813
Big Slide Creek region, Nunavut; Fosheim Peninsula, Nunavut; Hot Weather Creek region, Nunavut


A century (1910-2008) of change in a collapsing pingo, Parry Peninsula, western Arctic coast, Canada   /   Mackay, J.R.   Burn, C.R.
(Permafrost and periglacial processes, v. 22, no. 3, July 2011, p. 266-272, ill., map)
(PCSP/PPCP contribution, no. 003-11)
References.
The PCSP/PPCP contribution number is incorrectly given as 030-11 in the Acknowledgments of this article. The correct number is 003-11.
ASTIS record 76109.
Languages: English
Web: doi:10.1002/ppp.723
Libraries: ACU

An isolated, eroding pingo at the southern end of Parry Peninsula, N.W.T., Canada was first photographed in about 1910. The photograph allows examination of a century of landform change. Since 1910, the pingo crater pond has drained, the north side of the pingo has become well vegetated, the serrated crest has been smoothed, and the lake bottom has become colonised by willows and other vegetation. The height of the feature was over 100 ft (30 m) in 1910 and is now about 50 ft (15-17 m). The erosion of the pingo has probably been dominated by the strong southerly katabatic winds in the area, as the vegetation on the south side of the pingo is poorly developed in comparison with the north side. A secondary cause of erosion has been the numerous excavations by ground squirrels (Spermophilus parryii) and foxes (Vulpes lagopus) on the slopes of the pingo. It is unusual to detect change of collapsed pingos near the western Arctic coast of Canada unless ground ice is exposed in the core or on the sides of the pingo. (Au)

C, H, F, I, J, E, V
Active layer; Aerial photography; Climate change; Cores; Effects monitoring; Erosion; Foxes; Ground squirrels; History; Instruments; Measurement; Permafrost; Photography; Pingos; Plant cover; Plant growth; Plant-soil relationships; Publishing; Sand; Shrubs; Slopes; Snow; Temporal variations; Thawing; Thermal properties; Thermal regimes; Thermokarst; Thickness; Tundra ecology; Willows; Winds

G0812, G0811
Parry Peninsula, N.W.T.; Paulatuk, N.W.T.


An avian terrestrial predator of the Arctic relies on the marine ecosystem during winter   /   Therrien, J.-F.   Gauthier, G.   Bêty, J.
(Journal of avian biology, v. 42, no. 4, July 2011, p. 363-369, maps)
(PCSP/PPCP contribution, no. 004-11)
References.
ASTIS record 74853.
Languages: English
Web: doi:10.1111/j.1600-048X.2011.05330.x
Libraries: ACU

Top predators of the arctic tundra are facing a long period of very low prey availability during winter and subsidies from other ecosystems such as the marine environment may help to support their populations. Satellite tracking of snowy owls, a top predator of the tundra, revealed that most adult females breeding in the Canadian Arctic overwinter at high latitudes in the eastern Arctic and spend several weeks (up to 101 d) on the sea-ice between December and April. Analysis of high-resolution satellite images of sea-ice indicated that owls were primarily gathering around open water patches in the ice, which are commonly used by wintering seabirds, a potential prey. Such extensive use of sea-ice by a tundra predator considered a small mammal specialist was unexpected, and suggests that marine resources subsidize snowy owl populations in winter. As sea-ice regimes in winter are expected to change over the next decades due to climate warming, this may affect the wintering strategy of this top predator and ultimately the functioning of the tundra ecosystem. (Au)

I, J, G, E
Animal behaviour; Animal distribution; Animal food; Animal live-capture; Animal migration; Animal population; Animal reproduction; Climate change; Environmental impacts; Food chain; Ice cover; Marine ecology; Predation; Radio tracking of animals; SAR; Satellite communications; Satellite photography; Sea birds; Sea ice; Seasonal variations; Snowy Owls; Telemetry; Temporal variations; Tundra ecology; Wildlife habitat; Winter ecology

G0813, G0826, G0815, G0814, G09
Baffin Bay-Davis Strait; Baffin Island waters, Nunavut; Baffin Island, Nunavut; Bylot Island, Nunavut; Hudson Bay; Hudson Strait, Nunavut/Québec; Nunavik, Québec; Pond Inlet (Hamlet), Nunavut; Resolution Island, Nunavut; Sirmilik National Park, Nunavut


Microbes in High Arctic snow and implications for the cold biosphere   /   Harding, T.   Jungblut, A.D.   Lovejoy, C.   Vincent, W.F.
(Applied and environmental microbiology, v. 77, no. 10, May 2011, p.3234-3243, ill., maps)
(PCSP/PPCP contribution, no. 005-11)
References.
Supplemental material available online.
ASTIS record 74417.
Languages: English
Web: doi:10.1128/AEM.02611-10
Libraries: ACU

We applied molecular, microscopic, and culture techniques to characterize the microbial communities in snow and air at remote sites in the Canadian High Arctic (Ward Hunt Island, Ellesmere Island, and Cornwallis Island, latitudes 74 to 83°N). Members of the Bacteria and Eukarya were prevalent in the snow, and their small subunit (SSU) rRNA gene signatures indicated strong local aerial transport within the region over the preceding 8 months of winter snowpack accumulation. Many of the operational taxonomic units (OTUs) were similar to previously reported SSU rRNA gene sequences from the Arctic Ocean, suggesting the importance of local aerial transport processes for marine microbiota. More than 47% of the cyanobacterial OTUs in the snow have been previously found in microbial mats in the region, indicating that this group was also substantially derived from local sources. Viable cyanobacteria isolated from the snow indicated free exchange between the snow and adjacent mat communities. Other sequences were most similar to those found outside the Canadian Arctic but were from snow, lake and sea ice, glaciers and permafrost, alpine regions, Antarctica, and other regions of the Arctic, supporting the concept of global distribution of microbial ecotypes throughout the cold biosphere. (Au)

H, I, J, F, D, E
Animal anatomy; Animal distribution; Animal population; Animal taxonomy; Atmospheric chemistry; Atmospheric circulation; Bacteria; Benthos; Clouds; Cold adaptation; Cyanophyceae; Fresh-water biology; Fungi; Genetics; Glaciers; Groundwater; Ice shelves; Lakes; Marine biology; Microbial ecology; Microorganisms; Ocean currents; Plant anatomy; Plant distribution; Plant taxonomy; Pollen; Rivers; Sea water; Seasonal variations; Snow; Tundra ponds

G0813, G03
Arctic Ocean; Arctic regions; Char Lake, Nunavut; Ellesmere Island, Nunavut; Resolute Bay region, Nunavut; Ward Hunt Ice Shelf, Nunavut; Ward Hunt Island, Nunavut


Extreme ecosystems and geosystems in the Canadian High Arctic : Ward Hunt Island and vicinity   /   Vincent, W.F.   Fortier, D.   Lévesque, E.   Boulanger-Lapointe, N.   Tremblay, B.   Sarrazin, D.   Antoniades, D.   Mueller, D.R.
(Numéro spécial : De la forêt boréale au désert du Haut-Arctique : un numéro thématique commémorant les 50 années de recherche du Centre d'études nordiques (CEN) dans l'est du Canada = Special issue : From boreal forest to High Arctic desert : a theme issue commemorating 50 years of research by the Centre for Northern Studies (CEN) in eastern Canada. Écoscience, v. 18, no 3, Sept. 2011, p. 236-261, ill., maps)
(PCSP/PPCP contribution, no. 006-11)
Appendix.
References.
ASTIS record 75133.
Languages: English
Web: doi:10.2980/18-3-3448
Libraries: ACU

Global circulation models predict that the strongest and most rapid effects of global warming will take place at the highest latitudes of the Northern Hemisphere. Consistent with this prediction, the Ward Hunt Island region at the northern terrestrial limit of Arctic Canada is experiencing the onset of major environmental changes. This article provides a synthesis of research including new observations on the diverse geosystems/ecosystems of this coastal region of northern Ellesmere Island that extends to latitude 83.11° N (Cape Aldrich). The climate is extreme, with an average annual air temperature of -17.2 °C, similar to Antarctic regions such as the McMurdo Dry Valleys. The region is geologically distinct (the Pearya Terrane) and contains steep mountainous terrain intersected by deep fiords and fluvial valleys. Numerous glaciers flow into the valleys, fiords, and bays, and thick multi-year sea ice and ice shelves occur along the coast. These extreme ice features are currently undergoing rapid attrition. The polar desert landscape contains sparse, discontinuous patches of vegetation, including dense stands of the prostrate shrub Salix arctica (Artic willow) at some sites, and 37 species of vascular plants on Ward Hunt Island. Diverse aquatic ecosystems occur throughout the area, including meromictic, epishelf, and perennially ice-covered lakes. Many of these have responded strongly to climate shifts in the past and like other geosystems/ecosystems of the region are now sentinels of ongoing global climate change. (Au)

J, E, H, G, A, D, B, F, I
Archaea; Arctic willows; Atmospheric temperature; Bacteria; Biomass; Bottom sediments; Calving (Ice); Canada. Radarsat Project; Chlorophyll; Climate change; Cyanophyceae; Diatoms; Diurnal variations; Driftwood ; Fast ice; Fjords; Food chain; Fresh-water ecology; Fresh-water flora; Geomorphology; Glacier lakes; Glaciology; Ice islands; Ice shelves; Lake stratification; Lakes; Meteorology; Microbial ecology; Palaeoclimatology; Palaeohydrology; Periglacial landforms; Photosynthesis; Plant distribution; Plants (Biology); Polar deserts; Sea ice; Seasonal variations; Solar radiation; Temporal variations; Tundra ecology; Weather stations

G0813, G0815, G03
Ellesmere Island waters, Nunavut; Ellesmere Island, Nunavut; Milne Fiord, Nunavut; Milne Ice Shelf, Nunavut; Quttinirpaaq National Park, Nunavut; Ward Hunt Ice Shelf, Nunavut; Ward Hunt Island, Nunavut


Milne Fiord epishelf lake : a coastal Arctic ecosystem vulnerable to climate change   /   Veillette, J.   Lovejoy, C.   Potvin, M.   Harding, T.   Jungblut, A.D.   Antoniades, D.   Chénard, C.   Suttle, C.A.   Vincent, W.F.
(Numéro spécial : De la forêt boréale au désert du Haut-Arctique : un numéro thématique commémorant les 50 années de recherche du Centre d'études nordiques (CEN) dans l'est du Canada = Special issue : From boreal forest to High Arctic desert : a theme issue commemorating 50 years of research by the Centre for Northern Studies (CEN) in eastern Canada. Écoscience, v. 18, no 3, Sept. 2011, p. 304-316, ill., maps)
(PCSP/PPCP contribution, no. 007-11)
References.
ASTIS record 75135.
Languages: English
Web: doi:10.2980/18-3-3443
Libraries: ACU

Milne Fiord in the Canadian High Arctic contains the last known ice-dammed fiord lake (epishelf lake) in the Northern Hemisphere. This freshwater ecosystem is retained by the Milne Ice Shelf and is underlain by sea water that is connected to the Arctic Ocean. Using microscopy, photosynthetic pigment analyses, and molecular techniques we examined the planktonic communities present in Milne Fiord to determine the biotic characteristics of the epishelf lake and the sea water below. Net sampling of the water column of Milne Fiord revealed a mixture of marine, freshwater, and brackish Zooplankton taxa, and high performance liquid chromatography (HPLC) pigment analysis showed pronounced differences in phytoplankton composition through the highly stratified water column. Chlorophytes dominated in the epishelf lake, prasinophytes prevailed in the halocline, and the bottom layer harboured mainly fucoxanthin-containing groups. Clone libraries of a dark-incubated, concentrated sample from below the halocline (30 m depth) yielded marine Archaea (mainly Crenarchaeota) and known bacterial taxa from the Pacific and Arctic oceans (e.g., Roseobacter, Oleispira, Colwellia). An equivalent sample from the epishelf lake (5 m depth) yielded many bacterial taxa that are characteristic of cold, freshwater habitats (e.g., Polynucleobacter, Variovorax, Flavobacterium), the euryhaline genus Polaromonas, and freshwater eukaryotes, notably ciliates. Similarly, denaturing gradient gel electrophoresis (DGGE) analyses of T4-like bacteriophages showed different viral assemblages in the upper and lower water column. This diverse, stratified ecosystem is dependent on the integrity of the bounding ice shelf and is therefore vulnerable to the ongoing effects of climate change in this region. (Au)

J, I, H, E, D, F
Archaea; Bacteria; Biomass; Chemical oceanography; Chromatography; Climate change; Effects monitoring; Fjords; Fluorometry; Fresh-water ecology; Genetics; Glacier lakes; Heterotrophic bacteria; Ice shelves; Lake ice; Lake stratification; Marine ecology; Melting; Microbial ecology; Pack ice; Photosynthesis; Phytoplankton; Salinity; Sea ice; Temperature; Viruses; Water masses; Zooplankton

G03, G0813
Milne Fiord, Nunavut; Milne Glacier, Nunavut; Milne Ice Shelf, Nunavut


Volume and area changes of the Milne Ice Shelf, Ellesmere Island, Nunavut, Canada, since 1950   /   Mortimer, C.A.   Copland, L.   Mueller, D.R.
(Journal of geophysical research, v.117, F04011, Dec. 2012, 12 p., ill., maps)
(PCSP/PPCP contribution, no. 009-11)
References.
ASTIS record 76844.
Languages: English
Web: doi:10.1029/2011JF002074
Libraries: ACU

Ground penetrating radar (GPR) surveys of the 205 km² Milne Ice Shelf conducted in 2008 and 2009 are compared with radio echo sounding (RES) data from 1981 to provide the first direct measurements of thinning for any northern Ellesmere Island ice shelf. Our results show an average thinning for the ice shelf as a whole of 8.1 ± 2.8 m, with a maximum of >30 m, over this 28-year period. Direct-line comparisons along a 7.5 km transect near the front of ice shelf indicate a mean thinning of 2.63 ± 2.47 m over the same period. Reductions in areal extent (29%, 82 ± 8.4 km²: 1950–2009) and volume (13%, 1.5 ± 0.73 km³ water equivalent (w.e.): 1981–2008/2009) indicate that the Milne Ice Shelf has been in a state of negative mass balance for at least the last 59 years. A comparison of mean annual specific mass balance measurements with the nearby Ward Hunt Ice Shelf (WHIS) suggests that basal melt is a key contributor to Milne Ice Shelf thinning. Glacier inflow to the ice shelf has also reduced markedly over the past 28 years. The transition of ice shelf ice to lake ice was the most important source of mass loss. A 28.5 km² epishelf lake now exists on the landward side of the ice shelf. Given these recent changes, disintegration of the Milne Ice Shelf will almost certainly continue in the future. (Au)

F, E, G
Aerial photography; Calving (Ice); Effects monitoring; Effects of climate on ice; Fracturing; Glacier lake outbursts; Glacier lakes; Glaciers; Ground penetrating radar; Ice shelves; Lake ice; Mapping; Mass balance; Measurement; Melting; Radar; Remote sensing; SAR; Satellite photography; Sea ice; Spatial distribution; Temporal variations; Thickness

G0813, G03
Arctic Ocean; Milne Ice Shelf, Nunavut; Ward Hunt Ice Shelf, Nunavut


Loss of multiyear landfast sea ice from Yelverton Bay, Ellesmere Island, Nunavut, Canada   /   Pope, S.   Copland, L.   Mueller, D.
(Arctic, antarctic, and alpine research, v. 44, no. 2, May 2012, p. 210-221, ill., maps)
(PCSP/PPCP contribution, no. 010-11)
References.
ASTIS record 76845.
Languages: English
Web: doi:10.1657/1938-4246-44.2.210
Libraries: ACU

For much of the 20th century, multiyear landfast sea ice (MLSI) formed a permanent ice cover in Yelverton Bay, Ellesmere Island. This MLSI formed following the removal of ice shelf ice from Yelverton Bay in the early 1900s, including the well-documented Ice Island T-3. The MLSI cover survived intact for 55–60 years until 2005, when >690 km² (90%) of MLSI was lost from Yelverton Bay. Further losses occurred in 2008, and the last of the Yelverton Bay MLSI was lost in August 2010. Ground penetrating radar (GPR) transects and ice cores taken in June 2009 provide the first detailed assessment of MLSI in Yelverton Inlet, and indeed the last assessment now that it has all been replaced with first-year ice. A detailed history of ice shelf, glacier, and MLSI changes in Yelverton Bay since the early 1900s is presented using remotely sensed imagery (air photos, space-borne optical, and radar scenes) and ancillary evidence from in situ surveys. Recent changes in the floating ice cover here align with the broad-scale trend of long-term reductions in age and thickness of sea ice in the Arctic Ocean and Canadian Arctic Archipelago. (Au)

G, F, D
Aerial photography; Atmospheric temperature; Breakup; Calving (Ice); Cores; Fast ice; Fjords; Glacier ice; Ground penetrating radar; Ice cover; Ice islands; Ice shelves; Mass balance; Measurement; Melting; Radar; Remote sensing; Salinity; SAR; Satellite photography; Sea ice; Seismic surveys; Snow; Temperature; Temporal variations; Thickness

G0815, G03, G0813
Ellesmere Island waters, Nunavut; Kulutingwak Fiord, Nunavut; Nansen Sound, Nunavut; Sverdrup Channel, Nunavut; Wootton Peninsula, Nunavut; Yelverton Bay region, Nunavut; Yelverton Bay, Nunavut; Yelverton Inlet region, Nunavut


Seasonal and microhabitat influences on diatom assemblages and their representation in sediment traps and surface sediments from adjacent High Arctic lakes : Cape Bounty, Melville Island, Nunavut   /   Stewart, K.A.   Lamoureux, S.F.
(Hydrobiologia, v.683, no. 1, Mar. 2012, p. 265-286, ill., maps)
(PCSP/PPCP contribution, no. 015-11)
References.
The PCSP/PPCP contribution number is incorrectly given as 011-15 in the Acknowledgments of this article. The correct number is 015-11. Two publications have PCSP/PPCP contribution number 015-11. The other one is ASTIS record 75857.
ASTIS record 75152.
Languages: English
Web: doi:10.1007/s10750-011-0965-0
Libraries: ACU

The spatial (i.e. microhabitat) and temporal (i.e. seasonal) characteristics of diatom assemblages in adjacent High Arctic lakes were studied intensively June-August 2004. These baseline data are used to improve understanding of modern diatom community dynamics, as well to inform paleoenvironmental reconstructions. Diatoms were collected approximately weekly through the melt season from each principal benthic substrate (moss/macrophyte, rock scrapes, littoral sediment), plankton, and sediment traps, and were compared to the uppermost 0.5 cm of a surface core obtained from the deepest part of the lake where sediment cores are routinely collected. Water samples were collected concurrently with diatom samples to investigate species-environment relationships. The lakes share approximately half of their common taxa, the most abundant overall in both lakes being small Cyclotella species. Results of detrended correspondence analysis (DCA) indicate that the largest gradient in species turnover existed between benthic and planktonic communities in both lakes, and that sediment trap and the surface core top samples most closely resemble the planktonic assemblage, with an additional contribution from the lotic environment. Our results indicate clear micro-spatial controls on species assemblages and a degree of disconnection between the benthos and deep lake sediments that manifests as an under-representation of benthic taxa in deep lake surface sediments. These findings are particularly relevant in the context of interpreting the paleoenvironmental record and assessing ecosystem sensitivity to continued climate change. (Au)

F, B, E, H, J
Benthos; Bottom sediments; Chemical properties; Cores; Diatoms; Fresh-water ecology; Lakes; Mosses; Nitrogen; Palaeoecology; Palaeontology; Phosphorus; Plankton; Plant taxonomy; Seasonal variations; Sedimentation; Spatial distribution; Suspended solids; Watersheds

G0813
Bounty, Cape, region, Nunavut; East Lake, Nunavut; West Lake, Nunavut


Habitat change and the scale of habitat selection : shifting gradients used by coexisting Arctic rodents   /   Morris, D.W.   Dupuch, A.
(Oikos, v.121, no. 6, June 2012, p. 975-984, ill.)
(PCSP/PPCP contribution, no. 015-11)
References.
Two publications have PCSP/PPCP contribution number 015-11. The other one is ASTIS record 75152.
ASTIS record 75857.
Languages: English
Web: doi:10.1111/j.1600-0706.2011.20492.x
Libraries: ACU

The conservation and understanding of biodiversity requires development and testing of models that illustrate how climate change and other anthropogenic effects alter habitat and its selection at different spatial scales. Models of fitness along a habitat gradient illustrate the connection between fine-scale variation in fitness and the selection of habitat as discontinuous patches in the landscape. According to these models, climate change can increase fitness values of static habitats, shift the fitness value of habitat patches along underlying gradients of habitat quality, or alter both fitness and habitat quality. It should be possible to differentiate amongst these scenarios by associating differences in the abundance and distribution of species with metrics of habitat that document the gradient while controlling for changes in density at larger scales of analysis. Comparisons of habitat selection by two species of lemmings, over an interval of 15 years, are consistent with the theory. The pattern of habitat selection at the scale of wet versus dry tundra habitats changed through time. The change in habitat selection was reflected by different, but nevertheless density-dependent, patterns of association with the structure and composition of habitat. Abundant collared lemmings abandoned stations where altered habitat characteristics caused a shift to new locations along the wet-to-dry gradient. The confirmation of scale-dependent theory provides new insights into how one might begin to forecast future habitat selection under different scenarios of climate and habitat change. (Au)

I, J, H, A, E
Animal behaviour; Animal distribution; Animal live-capture; Animal population; Climate change; Dryas; Evolution (Biology); Forecasting; Grasses; Hummocks; Lemmings; Lichens; Meadows; Microclimatology; Plant cover; Plants (Biology); Sedges; Soil moisture; Temporal variations; Tundra ecology; Wildlife habitat

G0815
Kent Peninsula, Nunavut


Tracing groundwater discharge in a High Arctic lake using radon-222   /   Dugan, H.A.   Gleeson, T.   Lamoureux, S.F.   Novakowski, K.
(Environmental earth sciences, v. 66, no. 5, July 2012, p.1385-1392, ill., maps)
(PCSP/PPCP contribution, no. 016-11)
References.
The PCSP/PPCP contribution number is incorrectly given as 011-16 in the Acknowledgments of this article. The correct number is 016-11.
ASTIS record 76843.
Languages: English
Web: doi:10.1007/s12665-011-1348-6
Libraries: ACU

In the High Arctic, groundwater fluxes are limited by the presence of continuous permafrost, although it has been hypothesized that there may be localized groundwater flow and hydraulic connectivity beneath large lakes, due to the presence of taliks, or large regions of unfrozen ground. However, due to the logistical difficulty of employing seepage meters and piezometers in deep, ice-covered lakes, relatively little is known about groundwater discharge to polar lakes. One method of assessing groundwater discharge is through the use of geochemical tracers. We conducted a pilot study to quantify groundwater discharge into a High Arctic lake using dissolved radon gas as a geochemical tracer. Lake water was collected in 15 L polyvinyl chloride (PVC) bags with minimal atmospheric interaction from a 25-m deep lake near Shellabear Point, Melville Island, Northwest Territories, Canada. Sample bags were aerated through a closed water loop for 60 min to allow sufficient radon to equilibrate in a coupled air circuit. Radon in air concentrations were measured on a Durridge RAD7 portable alpha spectrometer. The field trial in a remote setting and separate tests with groundwater samples collected from a temperate site demonstrate the utility of the methodology. The limited results suggest that radon levels in the lower water column are elevated above background levels following nival melt in the surrounding watershed. Although these results are insufficient to quantify groundwater discharge, the results suggest subsurface flow may exist, and further study is warranted. (Au)

F, G, B, E, C, J
Atmospheric chemistry; Bottom sediments; Climate change; Composition; Density; Flow; Groundwater; Hydrology; Lake ice; Lake stratification; Lakes; Mathematical models; Measurement; Permafrost; Radionuclides; Radon; Rivers; Runoff; Salinity; Sea level; Seasonal variations; Sedimentary rocks; Snowmelt; Spectroscopy; Temporal variations; Thawing; Thermal regimes; Thickness; Tides; Watersheds

G0813, G0812
Dundas Peninsula, N.W.T./Nunavut; Shellabear Lake, N.W.T./Nunavut


Habitat selection, reproduction and predation of wintering lemmings in the Arctic   /   Duchesne, D.   Gauthier, G.   Berteaux, D.
(Oecologia, v.167, no. 4, Dec. 2011, p. 967-980, ill.)
(PCSP/PPCP contribution, no. 017-11)
References.
ASTIS record 74415.
Languages: English
Web: doi:10.1007/s00442-011-2045-6
Libraries: ACU

Snow cover has dramatic effects on the structure and functioning of Arctic ecosystems in winter. In the tundra, the subnivean space is the primary habitat of wintering small mammals and may be critical for their survival and reproduction. We have investigated the effects of snow cover and habitat features on the distributions of collared lemming (Dicrostonyx groenlandicus) and brown lemming (Lemmus trimucronatus) winter nests, as well as on their probabilities of reproduction and predation by stoats (Mustela erminea) and arctic foxes (Vulpes lagopus). We sampled 193 lemming winter nests and measured habitat features at all of these nests and at random sites at two spatial scales. We also monitored overwinter ground temperature at a subsample of nest and random sites. Our results demonstrate that nests were primarily located in areas with high micro-topography heterogeneity, steep slopes, deep snow cover providing thermal protection (reduced daily temperature fluctuations) and a high abundance of mosses. The probability of reproduction increased in collared lemming nests at low elevation and in brown lemming nests with high availability of some graminoid species. The probability of predation by stoats was density dependent and was higher in nests used by collared lemmings. Snow cover did not affect the probability of predation of lemming nests by stoats, but deep snow cover limited predation attempts by arctic foxes. We conclude that snow cover plays a key role in the spatial structure of wintering lemming populations and potentially in their population dynamics in the Arctic. (Au)

I, F, J, H, E
Animal distribution; Animal ecology; Animal population; Animal reproduction; Animal waste products; Arctic foxes; Bioclimatology; Biological sampling; Climate change; Freezing rain; Lemmings; Mathematical models; Mosses; Plant distribution; Predation; Slopes; Snow; Spatial distribution; Survival; Temporal variations; Thermal regimes; Topography; Tundra ecology; Weasels; Wildlife habitat; Winter ecology

G0813
Bylot Island, Nunavut; Sirmilik National Park, Nunavut


The tundra food web of Bylot Island in a changing climate and the role of exchanges between ecosystems   /   Gauthier, G.   Berteaux, D.   Bêty, J.   Tarroux, A.   Therrien, J.-F.   McKinnon, L.   Legagneux, P.   Cadieux, M.-C.
(Numéro spécial : De la forêt boréale au désert du Haut-Arctique : un numéro thématique commémorant les 50 années de recherche du Centre d'études nordiques (CEN) dans l'est du Canada = Special issue : From boreal forest to High Arctic desert : a theme issue commemorating 50 years of research by the Centre for Northern Studies (CEN) in eastern Canada. Écoscience, v. 18, no 3, Sept. 2011, p. 223-235, ill., maps)
(PCSP/PPCP contribution, no. 018-11)
Appendix.
References.
ASTIS record 75132.
Languages: English
Web: doi:10.2980/18-3-3453
Libraries: ACU

It is increasingly recognized that ecosystems are not closed systems and that exchanges of resources across ecosystem boundaries can have repercussions on food webs, especially in low productivity systems such as the terrestrial Arctic. However, because these exchanges can take multiple forms, assessing their significance in the functioning of the tundra food web is difficult. In this paper, we first review some important concepts related to resource exchanges between ecosystems and examine their relevance to the study of trophic interactions in the arctic tundra. An analysis of the Bylot Island food web in the Canadian Arctic using a mass-balance trophic model suggests that predators are the dominant force controlling this food web. However, an important feature of this ecosystem is that several top predators benefit from allochthonous inputs, either through the presence of migratory birds during the summer or the use of the marine environment as a foraging ground in winter. We also show that migratory birds may act as autochthonous resource exporters for lower trophic levels, for instance by removing nitrogen from the nutrient pool when young produced locally migrate south and die away from the system. Although these resource exchanges may be a general feature of several arctic terrestrial ecosystems, their importance in the functioning of the tundra food web remains to be determined. Through long-term monitoring, we found that primary production in wetlands of Bylot Island increased by 85% over a 20-y period, likely a consequence of the warming trend observed in the area. However, we have not detected any changes at higher trophic levels, which is consistent with a top-down control of this food web. Given the importance of resource exchanges between ecosystems in the dynamics of the tundra food web, a full investigation of the effects of climate change will require a broader cross-ecosystem perspective. (Au)

J, E, H, I, G
Animal migration; Animal population; Animals; Biological productivity; Biomass; Birds; Climate change; Effects monitoring; Effects of climate on plants; Environmental impacts; Food chain; Lemmings; Mammals; Nitrogen; Predation; Primary production (Biology); Raptors; Sea ice ecology; Seasonal variations; Snow Geese; Temporal variations; Trophic levels; Tundra ecology; Weather stations; Wetlands; Winter ecology

G0813, G0815
Bylot Island waters, Nunavut; Bylot Island, Nunavut; Pond Inlet (Hamlet), Nunavut


Balsam poplar (Populus balsamifera; Salicaceae) beyond the tree line in the western Canadian mainland Arctic (Northwest Territories   /   Saarela, J.M.   Gillespie, L.J.   Consaul, L.L.   Bull, R.D.
(Arctic, v. 65, no. 1, Mar. 2012, p. 1-12, ill., maps)
(PCSP/PPCP contribution, no. 019-11)
Appendix.
References.
ASTIS record 76093.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic65-1-1.pdf
Web: doi:10.14430/arctic4161
Libraries: ACU

Balsam poplar is the northernmost tree species in North America, with a reported range that extends generally to the tree line across the continent and beyond the tree line in Alaska, where extralimital stands growing in Arctic ecosystems on the North Slope have been documented and studied. Here we summarize existing information and report new data on extralimital stands of balsam poplar from the Arctic ecozone in the northeastern mainland Northwest Territories. These occurrences extend the geographical and ecological range of the species fully into the mainland Canadian Arctic. In this region, balsam poplar is known from four sites: two in Tuktut Nogait National Park and two along the Hornaday and Brock rivers just beyond the northwestern Park boundary. Balsam poplar was first reported from two of these sites more than 50 years ago, but those data have not been considered in most subsequent floristic and ecological work. A balsam poplar grove in Tuktut Nogait National Park consists of four discrete stands of shrubby plants growing on a low ridge adjacent to the Hornaday River; their tallest ramets measure 1.1-1.86 m. A larger grove along the edge of the lower Brock River consists of three large stands, the tallest ramets measuring 3.5-4 m. The boreal and subarctic regions of the Northwest Territories and Nunavut have large areas where balsam poplar has not been documented by herbarium specimens, including most of the forest-tundra and tree-line zones. Collections from these areas and other potential extralimital sites in the Canadian Arctic are urgently needed to document the current distribution of balsam poplar. Such data could serve as a baseline for assessing potential future alteration of the range of this species as a result of climate change. (Au)

H, E, J
Climate change; Effects of climate on plants; Plant collections; Plant distribution; Plant ecology; Plant growth; Plants (Biology); Poplars; Size; Treeline

G0812
Brock River region, N.W.T.; Hornaday River region, N.W.T.; N.W.T.; Tuktut Nogait National Park, N.W.T.


Multitemporal analysis of a gravel-dominated coastline in the central Canadian Arctic Archipelago   /   St-Hilaire-Gravel, D.   Forbes, D.L.   Bell, T.
(Journal of coastal research, v. 28, no. 2, Mar. 2012, p. 421-441, ill., maps)
(PCSP/PPCP contribution, no. 022-11)
References.
ESS contribution no. 20110126.
ASTIS record 75208.
Languages: English
Web: doi:10.2112/JCOASTRES-D-11-00020.1
Libraries: ACU

This study assesses the stability of Arctic gravel coasts across a range of timescales, based on field and remote-sensing studies of three coastal sites near Resolute Bay, Nunavut. It considers shore-zone sensitivity to ice, wind, and wave forcing at storm-event and annual timescales within a longer-term context, including coastal emergence resulting from postglacial isostatic uplift partially counteracted by accelerating sea-level rise. Another long-term factor associated with climate change is the potential for increased seasonal depth of thaw in the beachface and nearshore. The coast in this area is ice bound on average for 10 months of the year, but the annual duration of ice cover has decreased over the past 30 years (1979-2009) by 0.95 d/y. A longer open-water season has implications for the number and timing of storm-wave events, with increased probability of storms impacting the coast later in the season when the seasonal thaw layer is approaching maximum thickness. Overall, shoreline progradation surpassed erosion in the Resolute area between 1958 and 2006, reflecting a combination of sediment supply and emergence. The coastal impacts of storms were found to be short lived and not necessarily indicative of longer-term trends. Gravel shorelines can be resilient in the face of intermittent storm impacts, but thresholds of stability in this high-latitude setting are poorly understood. If current trends of rising sea level, increasing open-water duration, and more frequent effective wave events continue, there is a heightened potential for more rapid coastal change in the region. (Au)

D, J, A, E, G, B
Beach erosion; Beaches; Breakup; Climate change; Coast changes; Effects monitoring; Environmental impacts; Forecasting; Geology; Geomorphology; Gravel; Ice cover; Mapping; Measurement; Ocean waves; Remote sensing; Sea ice; Sea level; Sediment transport; Sedimentation; Sediments (Geology); Shorelines; Storms; Submarine topography; Temporal variations; Thickness; Winds

G0813, G0815
Allen Bay region, Nunavut; Martyr, Cape, Nunavut; Resolute Bay region, Nunavut; Sight Point, Nunavut


Hydrochemical and sedimentary responses of paired High Arctic watersheds to unusual climate and permafrost disturbance, Cape Bounty, Melville Island, Canada   /   Lewis, T.   Lafrenière, M.J.   Lamoureux, S.F.
(Hydrological processes, v. 26, no. 13, 30 June 2012, p.2003-2018, ill, maps)
(PCSP/PPCP contribution, no. 023-11)
References.
ASTIS record 74925.
Languages: English
Web: doi:10.1002/hyp.8335
Libraries: ACU

High Arctic river responses to changing hydroclimatic and landscape processes are poorly understood. In non-glacierized basins, snowmelt and rainfall generate river discharge, which provides first order control over fluxes. Further factors include the seasonality of precipitation, seasonal active layer development, and permafrost disturbance. These controls were evaluated in terms of sedimentary and biogeochemical fluxes from paired catchments at Cape Bounty, Melville Island, Nunavut during 2006-2009. Results indicate that the source of runoff can be more important than the amount of runoff for sediment, solutes, and organic yields. Although the snowmelt period is typically the most important time for these yields, heavy late summer precipitation events can create disproportionately large yields. Rainfall increases yields because it hydrologically connects areas otherwise isolated. Inorganic solute yields from late summer rainfall are higher because the thick active layer maximizes hydrologic interactions with mineral soils and generates high solute concentrations. Results also indicate that while the catchments are broadly similar, subtle topographic differences result in important inter-catchment differences in runoff and suspended and dissolved loads. The East watershed, which had less extensive permafrost disturbance, consistently had higher concentrations of dissolved solids. These higher dissolved fluxes cannot therefore be explained by thermokarst features, but rather by deeper active layer development, due to a greater proportion of south-facing slopes. Although warm temperatures in 2007 led to extensive active layer disturbance in the West watershed, because the disturbances were largely hydrologically disconnected, the total disturbed area was small, and inter-annual variability in discharge was high, there was no detectable response in dissolved loads to disturbances. Sediment availability increased after 2007, but yields have largely returned to predisturbance levels. Results indicate that seasonality and frequency-magnitude characteristics of projected increases in precipitation must be considered along with active layer changes to predict the fluvial sedimentary and biogeochemical response to regional climate change. (Au)

F, E, J, C
Active layer; Carbon cycling; Chemical properties; Climate change; Effects of climate on permafrost; Environmental impacts; Geochemistry; Hydrology; Meteorology; Permafrost; Precipitation (Meteorology); Rain; Runoff; Seasonal variations; Sediment transport; Soil chemistry; Suspended solids; Thaw flow slides; Topography; Water quality

G0813
Bounty, Cape, region, Nunavut


Toponymy of Herschel Island (Qikiqtaryuk), western Arctic coast, Canada   /   Burn, C.R.   Hattendorf, J.B.
(Arctic, v. 64, no. 4, Dec. 2011, p. 459-464, ill., maps)
(PCSP/PPCP contribution, no. 024-11)
References.
ASTIS record 75087.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic64-4-459.pdf
Web: doi:10.14430/arctic4145
Libraries: ACU

The official names for several of the features on Herschel Island are derived from the visit to the island by USS Thetis, Lt. Cdr. Charles Stockton commanding, on 15 - 16 August 1889. In 24 hours, Stockton and his crew surveyed the coast sufficiently to compile and publish a map, which included the bathymetry of Pauline Cove and the strait between the island and the mainland, now called Workboat Passage. Stockton named features after two whaling ships that were in the vicinity when he arrived (Orca and Thrasher), his own Thetis, his wife (Pauline Lethilhon King), three ensigns to whom he assigned bathymetric surveys (Robert Lopez, Edward Simpson, and Rogers Wells, Jr.), two of his other officers (Lt. Arthur Osborn and Ensign John Bell), and an officer of the Royal Navy (Capt. Sir Richard Collinson). Only one feature, Avadlek Spit, has an Inuvialuktun official name. (Au)

V, A
Bathymetry; Exploration; Geographical names; Mapping; Surveying; Thetis (Ship)

G0811, G07
Canadian Beaufort Sea; Herschel Island, Yukon; Pauline Cove, Yukon; Workboat Passage, Yukon


Spatial variation in food availability predicts extrapair paternity in the arctic fox   /   Cameron, C.   Berteaux, D.   Dufresne, F.
(Behavioral ecology, v. 22, no. 6, Nov.-Dec. 2011, p.1364-1373, ill., maps)
(PCSP/PPCP contribution, no. 025-11)
References.
ASTIS record 74851.
Languages: English
Web: doi:10.1093/beheco/arr158
Libraries: ACU

Extrapair paternity (EPP) is described in many socially monogamous species, but within-population variability in its frequency is poorly documented. Availability and distribution of food may influence polyandrous behaviors, either directly by affecting the need for paternal care or indirectly via their effect on population density. We quantified the frequency of EPP in a population of arctic foxes (Vulpes lagopus), a predominantly socially monogamous species with high paternal investment. We then tested whether spatial (presence of a goose colony) and temporal (cycles of lemmings) variations in food availability were linked to variations in mating systems within the population. From 2003 to 2008, we studied the mating systems of arctic foxes on Bylot Island (Nunavut, Canada) by combining molecular analyses with behavioral observations during cub rearing. Although the dominant social mating system was monogamy, at least 31% of cubs with known social father were born from extrapair matings (in 10 of 38 litters sampled). Likelihood of EPP was associated with food availability. It was greatest (86%) at the center of the goose colony and decreased sharply with increasing distance from it. EPP can thus be frequent in the socially monogamous arctic fox, and intraspecific variability in extrapair matings is strongly correlated with food availability during cub rearing. (Au)

I, J
Animal behaviour; Animal distribution; Animal food; Animal live-capture; Animal population; Animal reproduction; Animal tagging; Arctic foxes; Bird nesting; Denning; Gender differences; Genetics; Greater Snow Geese; Lemmings; Temporal variations

G0813
Bylot Island, Nunavut


Chrysophytes and other protists in High Arctic lakes : molecular gene surveys, pigment signatures and microscopy   /   Charvet, S.   Vincent, W.F.   Lovejoy, C.
(Polar biology, v. 35, no. 5, May 2012, p. 733-748, ill., maps)
(PCSP/PPCP contribution, no. 027-11)
References.
Supplementary material available online.
ASTIS record 74934.
Languages: English
Web: doi:10.1007/s00300-011-1118-7
Libraries: ACU

Microscopic analysis of the phytoplankton and other protist communities in High Arctic lakes has shown that they often contain taxa in the Chrysophyceae. Such studies have been increasingly supported by pigment analysis using high-performance liquid chromatography (HPLC) to identify the major algal groups. However, the use of 18S rRNA gene surveys in other systems indicates that many protists, especially small heterotrophs, are underreported or missed by microscopy and HPLC. Here, we investigated the late summer protist community structure of three contrasting lakes in High Arctic polar desert catchments (Char Lake at 74°42'N, Lake A at 83°00'N and Ward Hunt Lake at 83°05'N) with a combination of microscopy, pigment analysis and small subunit 18S ribosomal RNA gene surveys. All three methods showed that chrysophytes were well represented, accounting for 50-70% of total protist community biomass and 25-50% of total 18S rRNA gene sequences. HPLC analysis supported these observations by showing the ubiquitous presence of chrysophyte pigments. The clone libraries revealed a greater contribution of heterotrophs to the protist communities than suggested by microscopy. The flagellate Telonema and ciliates were common in all three lakes, and one fungal sequence was recovered from Char Lake. The approaches yielded complementary information about the protist community structure in the three lakes and underscored the importance of chrysophytes, suggesting that they are well adapted to cope with the low nutrient supply and strong seasonality that characterize the High Arctic environment. (Au)

H, I, J, F
Algae; Ammonium; Biological sampling; Biomass; Chlorophyll; Chromatography; Ciliata; Climate change; Cyanophyceae; Dinoflagellata; Electrical properties; Environmental impacts; Fluorometry; Food chain; Fresh-water biology; Fresh-water ecology; Genetics; Identification; Lakes; Microbial ecology; Nitrogen; Phosphorus; Phytoplankton; Plant distribution; Plant taxonomy; Protozoa; Temperature

G0813
Char Lake, Nunavut; Ellesmere Island, Nunavut; Ward Hunt Island, Nunavut


Metagenomic analysis of stress genes in microbial mat communities from Antarctica and the High Arctic   /   Varin, T.   Lovejoy, C.   Jungblut, A.D.   Vincent, W.F.   Corbeil, J.
(Applied and environmental microbiology, v. 78, no. 2, Jan. 2012, p. 549-559, ill.)
(PCSP/PPCP contribution, no. 029-11)
References.
Supplemental material available online.
ASTIS record 75518.
Languages: English
Web: doi:10.1128/AEM.06354-11
Libraries: ACU

Polar and alpine microbial communities experience a variety of environmental stresses, including perennial cold and freezing; however, knowledge of genomic responses to such conditions is still rudimentary. We analyzed the metagenomes of cyanobacterial mats from Arctic and Antarctic ice shelves, using high-throughput pyrosequencing to test the hypotheses that consortia from these extreme polar habitats were similar in terms of major phyla and subphyla and consequently in their potential responses to environmental stresses. Statistical comparisons of the protein-coding genes showed similarities between the mats from the two poles, with the majority of genes derived from Proteobacteria and Cyanobacteria; however, the relative proportions differed, with cyanobacterial genes more prevalent in the Antarctic mat metagenome. Other differences included a higher representation of Actinobacteria and Alphaproteobacteria in the Arctic metagenomes, which may reflect the greater access to diasporas from both adjacent ice-free lands and the open ocean. Genes coding for functional responses to environmental stress (exopolysaccharides, cold shock proteins, and membrane modifications) were found in all of the metagenomes. However, in keeping with the greater exposure of the Arctic to long-range pollutants, sequences assigned to copper homeostasis genes were statistically (30%) more abundant in the Arctic samples. In contrast, more reads matching the sigma B genes were identified in the Antarctic mat, likely reflecting the more severe osmotic stress during freeze-up of the Antarctic ponds. This study underscores the presence of diverse mechanisms of adaptation to cold and other stresses in polar mats, consistent with the proportional representation of major bacterial groups. (Au)

H, I, F, J
Amino acids; Animal physiology; Animal taxonomy; Bacteria; Biological sampling; Carbohydrates; Cold adaptation; Cold physiology; Copper; Cyanophyceae; Electrical properties; Genetics; Glacial melt waters; Metabolism; Microbial ecology; Microorganisms; Plant physiology; Plant taxonomy; Proteins; Psychrophilic bacteria; Psychrotrophic bacteria; Puddles; Temperature; Thickness; Water pH; Wildlife habitat

G0813, G15, G03
Markham Fiord, Nunavut; McMurdo Ice Shelf, Antarctic regions; Ward Hunt Ice Shelf, Nunavut


Relationships between iceberg plumes and sea-ice conditions on northeast Devon Ice Cap, Nunavut, Canada   /   Herdes, E.   Copland, L.   Danielson, B.   Sharp, M.
(Annals of glaciology, v. 53, no. 60, 2012, 9 p., ill., map)
(PCSP/PPCP contribution, no. 030-11)
References.
ASTIS record 76108.
Languages: English
Web: doi:10.3189/2012AoG60A163
Libraries: ACU

This study investigates the impact of sea-ice conditions on the production of iceberg plumes from two tidewater glaciers on Devon Ice Cap, Nunavut, Canada. These effects are quantified using a 12 year RADARSAT-1 satellite record from 1997-2008 that contains imagery from approximately every 1-2 weeks in the winter and every 1-4 days in the summer. Iceberg plumes identified in this record are verified against terrestrial time-lapse photography of Belcher Glacier from 2007-08. Results suggest a strong relationship between iceberg plumes and the retreat of sea ice from the glacier termini, with the plumes caused by both the release of previously calved icebergs (ice melange) and new glacier calving. Iceberg plumes are also sometimes observed at other times in the summer and in midwinter (occasionally on both glaciers simultaneously), with these events likely due to new glacier calving alone. Analysis of tides and air temperatures suggests that they provide a minor influence on the timing of iceberg plumes. Instead, it appears that changes in the presence of sea ice are dominant on seasonal timescales, although internal glacier dynamics likely play a significant role for winter plume events that occur when substantial thicknesses of landfast sea ice are present. (Au)

F, E, D, G
Atmospheric temperature; Breakup; Calving (Ice); Climate change; Detection; Effects of climate on ice; Fast ice; Formation; Glacial melt waters; Glaciers; Ice caps; Icebergs; Melting; Ocean waves; SAR; Satellite photography; Sea ice; Seasonal variations; Spatial distribution; Surface properties; Temporal variations; Thickness; Tides; Winds

G0813, G0815
Belcher Glacier, Nunavut; Devon Ice Cap, Nunavut; Lady Ann Strait, Nunavut; Pond Inlet (Hamlet), Nunavut


Lemming winter habitat choice : a snow-fencing experiment   /   Reid, D.G.   Bilodeau, F.   Krebs, C.J.   Gauthier, G.   Kenney, A.J.   Gilbert, B.S.   Leung, M.C.-Y.   Duchesne, D.   Hofer, E.
(Oecologia, v.168, no. 4, Apr. 2012, p. 935-946, ill.)
(PCSP/PPCP contribution, no. 031-11)
References.
ASTIS record 74882.
Languages: English
Web: doi:10.1007/s00442-011-2167-x
Libraries: ACU

The insulative value of early and deep winter snow is thought to enhance winter reproduction and survival by arctic lemmings (Lemmus and Dicrostonyx spp). This leads to the general hypothesis that landscapes with persistently low lemming population densities, or low amplitude population fluctuations, have a low proportion of the land base with deep snow. We experimentally tested a component of this hypothesis, that snow depth influences habitat choice, at three Canadian Arctic sites: Bylot Island, Nunavut; Herschel Island, Yukon; Komakuk Beach, Yukon. We used snow fencing to enhance snow depth on 9-ha tundra habitats, and measured the intensity of winter use of these and control areas by counting rodent winter nests in spring. At all three sites, the density of winter nests increased in treated areas compared to control areas after the treatment, and remained higher on treated areas during the treatment. The treatment was relaxed at one site, and winter nest density returned to pre-treatment levels. The rodents' proportional use of treated areas compared to adjacent control areas increased and remained higher during the treatment. At two of three sites, lemmings and voles showed significant attraction to the areas of deepest snow accumulation closest to the fences. The strength of the treatment effect appeared to depend on how quickly the ground level temperature regime became stable in autumn, coincident with snow depths near the hiemal threshold. Our results provide strong support for the hypothesis that snow depth is a primary determinant of winter habitat choice by tundra lemmings and voles. (Au)

I, F, J, E
Animal behaviour; Animal distribution; Animal ecology; Animal population; Animal reproduction; Atmospheric temperature; Bioclimatology; Density; Lemmings; Mapping; Snow; Snow cover; Snow fences; Snowdrifts; Temporal variations; Thermal properties; Thickness; Tundra ecology; Voles; Wildlife habitat; Winter ecology

G0813, G0811
Bylot Island, Nunavut; Herschel Island, Yukon; Ivvavik National Park, Yukon; Komakuk Beach, Yukon; Sirmilik National Park, Nunavut


Geomorphology of a thermo-erosion gully, Bylot Island, Nunavut, Canada   /   Godin, E.   Fortier, D.
(Fundamental and applied research on permafrost in Canada / Edited by Michel Allard. Canadian journal of earth sciences, v. 49, no. 8, Aug. 2012, p. 979-986, ill., maps)
(PCSP/PPCP contribution, no. 031-11)
References.
ASTIS record 79140.
Languages: English
Web: doi:10.1139/E2012-015
Libraries: ACU

A thermo-erosion gully has been monitored in the valley of glacier C-79 on Bylot Island since 1999. The main channel of the gully reached 390 m in length a few months after its initiation and grew between 38 and 50 m/year over the following decade, for an overall approximated average of 75 m/year. In 2009, the total gully length and area, including the main and relict channels, were 2500 m and 25 000 m², respectively. Gullies affect snow accumulation, and therefore ground temperature, local water flow, and drainage. Sinkholes, gully heads, pools, baydzherakhi, tunnels, and collapses were grouped as a function of time since gully formation in that area. Sinkholes and tunnels were formed every year after gully inception, and baydzherakhi were found in 3-10 year old sections of the gully. Stabilization of the gully floor and sides took about a decade. ... The active layer depth may vary from 50-60 cm in peaty-silts to 1 m in sands and gravels .... (Au)

C, F, A, E, B
Active layer; Climate change; Drainage; Effects monitoring; Environmental impacts; Erosion; Geomorphology; Glacial melt waters; Glaciers; Gravel; Ground ice; Heat transmission; Ice wedges; Mass wasting; Patterned ground; Periglacial landforms; Permafrost; River discharges; Runoff; Sand; Sediment transport; Snowmelt; Stream erosion; Temporal variations; Thaw flow slides; Thawing; Thermal regimes; Valleys

G0813
Bylot Island, Nunavut


Holocene dynamics of the Arctic's largest ice shelf   /   Antoniades, D.   Francus, P.   Pienitz, R.   St-Onge, G.   Vincent, W.F.
(Proceedings of the National Academy of Sciences of the United States of America, v.108, no. 47, Nov. 22, 2011, p.18899-18904, ill., maps)
(PCSP/PPCP contribution, no. 032-11)
References.
Supporting information is available online.
ASTIS record 74848.
Languages: English
Web: doi:10.1073/pnas.1106378108
Libraries: ACU

Ice shelves in the Arctic lost more than 90% of their total surface area during the 20th century and are continuing to disintegrate rapidly. The significance of these changes, however, is obscured by the poorly constrained ontogeny of Arctic ice shelves. Here we use the sedimentary record behind the largest remaining ice shelf in the Arctic, the Ward Hunt Ice Shelf (Ellesmere Island, Canada), to establish a long-term context in which to evaluate recent ice-shelf deterioration. Multiproxy analysis of sediment cores revealed pronounced biological and geochemical changes in Disraeli Fiord in response to the formation of the Ward Hunt Ice Shelf and its fluctuations through time. Our results show that the ice shelf was absent during the early Holocene and formed 4,000 years ago in response to climate cooling. Paleoecological data then indicate that the Ward Hunt Ice Shelf remained stable for almost three millennia before a major fracturing event that occurred ~1,400 years ago. After reformation ~800 years ago, freshwater was a constant feature of Disraeli Fiord until the catastrophic drainage of its epishelf lake in the early 21st century. (Au)

B, J, F, D, E
Bottom sediments; Breakup; Carbon; Climate change; Cores; Effects of climate on ice; Environmental impacts; Fracturing; Geochemistry; Glacier lake outbursts; Glacier lakes; Glaciology; Ice shelves; Lakes; Palaeoecology; Palaeogeography; Radiocarbon dating; Recent epoch; Temporal variations

G0813, G03
Disraeli Fiord, Nunavut; Ward Hunt Ice Shelf, Nunavut


Spatial patterns of snow accumulation across Belcher Glacier, Devon Ice Cap, Nunavut, Canada   /   Sylvestre, T.   Copland, L.   Demuth, M.N.   Sharp, M.
(Journal of glaciology, v. 59, no.217, Oct. 2013, p. 874-882, ill., maps)
(PCSP/PPCP contribution, no. 033-11)
References.
Natural Resources Canada Earth Sciences Center (ESS) contribution no. 20110344.
ASTIS record 79612.
Languages: English
Web: doi:10.3189/2013JoG12J227
Libraries: ACU

Ground-penetrating radar (GPR) surveys at a center frequency of 500 MHz were used to determine winter (2007/08) and net annual (2005-07) snow water equivalent (SWE) patterns across the upper parts of Belcher Glacier, Devon Ice Cap, Nunavut, Canada. The GPR measurements were validated against snow depths determined from avalanche probe measurements, and converted to SWE values using densities measured with a down-borehole neutron density probe and in shallow snow pits. Distinct internal reflection horizons (IRHs) in the GPR record were formed during warm summers in 2007 and 2005, and a large rain event in summer 2006 which caused ice to accumulate above the 2005 melt surface. Elevation provides the dominant control on winter SWE distribution across the basin, with surface topography (e.g.gullies) also being locally important. Based on the location where IRHs intersected the ice-cap surface, the basin-wide firn line occurred at an altitude of 1260-1300 m over the period 2005-08. Net mass balance across the accumulation area of Belcher Glacier averaged 0.24 m/w.e.a over the period 2005-07, mainly dependent on altitude. This is a little higher than most previous estimates for the period since the 1960s, although the differences lie within error limits. (Au)

F, E
Ablation; Accumulation; Boreholes; Chemical properties; Climate change; Cores; Density; Firn; Glacial stratigraphy; Glaciers; Ground penetrating radar; Ice shelves; Mass balance; Snow; Snow cover; Snow water equivalent; Temporal variations; Topography

G0813
Belcher Glacier, Nunavut; Devon Ice Cap, Nunavut


Lake- and channel-bottom temperatures in the Mackenzie Delta, Northwest Territories   /   Ensom, T.P.   Burn, C.R.   Kokelj, S.V.
(Fundamental and applied research on permafrost in Canada / Edited by Michel Allard. Canadian journal of earth sciences, v. 49, no. 8, Aug. 2012, p. 963-978, ill., maps)
(PCSP/PPCP contribution, no. 035-11)
Appendix.
References.
ASTIS record 76475.
Languages: English
Web: doi:10.1139/e2012-001
Libraries: ACU

Temperature loggers were placed in 17 lakes and 13 channels throughout the Mackenzie Delta to determine the annual mean bottom temperature (mean Tb) and its spatial and temporal variation for June 2009 - June 2010. The lakes were classified as perched or connected, depending on the duration of their connection to the channel hydrologic system. Average mean Tb values for nine perched lakes, five channels, and eight connected lakes distributed throughout the Mackenzie Delta were 5.5, 4.6, and 3.4 °C, respectively. The range of mean Tb among all instrumented water bodies in the Delta was 4.0 °C. Over the year, bottom temperatures ranged from >20 °C in midsummer to -5 °C in midwinter, with relative stability between freeze-up in mid-October and breakup at the beginning of June. Channel, perched, and connected lake mean Tb, and mean annual near-surface ground temperatures of -4 °C in alluvial sedge wetlands and –2.25 °C in forest, were used to estimate that about 60% of Delta lakes and nearly the entire channel network maintain through-taliks. (Au)

C, F, A, B, E
Bottom sediments; Geographic information systems; Lakes; Measurement; Permafrost; Rivers; Seasonal variations; Soil temperature; Spatial distribution; Temperature; Temporal variations; Thermal regimes

G0812
Mackenzie Delta, N.W.T.


Factors influencing permafrost temperatures across tree line in the uplands east of the Mackenzie Delta, 2004-2010   /   Palmer, M.J.   Burn, C.R.   Kokelj, S.V.
(Fundamental and applied research on permafrost in Canada / Edited by Michel Allard. Canadian journal of earth sciences, v. 49, no. 8, Aug. 2012, p. 877-894, ill., maps)
(PCSP/PPCP contribution, no. 036-11)
Appendix.
References.
ASTIS record 76477.
Languages: English
Web: doi:10.1139/e2012-002
Libraries: ACU

Air and near-surface ground temperatures, late-winter snow conditions, and characteristics of the vegetation cover and soil were measured across the forest-tundra transition in the uplands east of the Mackenzie Delta, Northwest Territories, in 2004-2010. Mean late-winter snow depth decreased northward from 73 cm in the subarctic boreal forest near Inuvik to 22 cm in low-shrub tundra. Annual near-surface ground temperatures decreased northward by 0.1-0.3 °C/km near the northern limit of trees, in association with an abrupt change in snow depth. The rate decreased to 0.01-0.06 °C/km in the tundra. The freezing season is twice as long as the thawing season in the region, so measured differences in the regional ground thermal regime were dominated by the contrast in winter surface conditions between forest and tundra. (Au)

C, F, E, H, J
Active layer; Atmospheric temperature; Density; Measurement; Permafrost; Plant cover; Plant-soil relationships; Shrubs; Snow; Soil temperature; Spatial distribution; Taiga ecology; Temperature; Temporal variations; Thermal regimes; Treeline; Tundra ecology

G0812
Inuvik region, N.W.T.; Mackenzie Delta, N.W.T.; Parsons Lake region, N.W.T.


Survival and reproduction of adult Snowy Owls tracked by satellite   /   Therrien, J.-F.   Gauthier, G.   Bêty, J.
(The Journal of wildlife management, v. 76, no. 8, Nov. 2012, p.1562-1567)
(PCSP/PPCP contribution, no. 038-11)
References.
ASTIS record 76590.
Languages: English
Web: doi:10.1002/jwmg.414
Libraries: ACU

Satellite telemetry can provide valuable information on spatial ecology of animals, especially in species inhabiting remote areas such as the Arctic. However, caution is always needed when selecting transmitter size and attachment methods because of the potential negative impact of the device itself on individuals. We determined survival and reproductive performance of adult female snowy owls (Bubo scandiacus) tracked by satellite to evaluate potential adverse effects of transmitters. In summer 2007, we captured 12 adult females on their nest in the Canadian Arctic, marked them with 30-g harness-mounted transmitters, and tracked their movement for up to 3 years. All marked birds resumed normal activities shortly (<60 min) after release and none deserted their nest. We had 2 known deaths and 2 transmitters that stopped moving over 3 years, yielding an annual survival rate between 85.2±7.0% and 92.3±5.7%. Moreover, summer movement patterns, combined with ground checks in several cases, suggested that all successfully tracked birds initiated a nest every year after marking. Finally, laying date and clutch size of individuals did not differ before and after marking. Overall, our data indicate that life history traits of adult female snowy owls were not affected by satellite transmitters. (Au)

I, N, J
Animal behaviour; Animal health; Animal live-capture; Animal mortality; Animal physiology; Animal population; Animal reproduction; Animal tagging; Bird nesting; Effects monitoring; Environmental impacts; Instruments; Radio tracking of animals; Research; Snowy Owls; Telemetry; Testing; Wildlife management

G0813
Bylot Island, Nunavut


Red-throated Loon monitoring in the southeast Beaufort Sea region : 2007-2008 update   /   Dickson, D.L.   Beaubier, J.
Edmonton, Alta. : Canadian Wildlife Service, Prairie and Northern Region, 2011.
vi, 38 p. : ill., maps ; 28 cm.
(Technical report series - Canadian Wildlife Service, no.517)
(PCSP/PPCP contribution, no. 039-11)
ISBN 978-1-100-19498-1
Appendices.
References.
Also available in French.
ASTIS record 76165.
Languages: English
Web: http://www.ec.gc.ca/Publications/34C89BDE-92E5-4390-AD3C-A4A3180C50E4%5CRedThroatedLoonMonitoringInTheSoutheastBeaufortSeaRegion20072008UpdateTR517.pdf
Libraries: ACU

In 1985, the Canadian Wildlife Service initiated a long-term monitoring program using the Red-throated Loon as an indicator of the environmental change that could result from offshore oil and gas development in the Beaufort Sea. Data were collected for five years at five study plots to obtain a predevelopment baseline measure of the abundance and productivity of loons in the region. Renewed interest in offshore hydrocarbon extraction prompted a second set of aerial surveys conducted in 2007 and 2008 at four of the five study plots. The same survey method was used, so that results could be directly compared to the earlier surveys. There was little change in the number of Red-throated Loon resident pairs between the two survey periods at all four study plots combined (185 ± 19.3 pairs during 1985-1989 compared to 197 ± 36.8 in 2007-2008). However, when each plot was examined separately, the number of resident pairs at the Toker Point plot had increased by 28%. Productivity likewise remained unchanged at three of the four plots, with an increase occurring only at Toker Point. The marked increase at Toker Point was likely a result of depressed productivity during the earlier survey period (1985-1989) caused by disturbance from intensive searches on foot throughout the nesting season. The more recent measure of productivity at Toker Point (0.9 ± 0.2 chicks per resident pair in 2007-2008) is therefore more representative of the natural undisturbed state. For results to be comparable across years, surveys must be timed to correspond with peak incubation period and dates when chicks are 4 to 5 weeks old. To address this problem we developed an equation that predicts timing of nest initiation based on the date when temperatures at Tuktoyaktuk reached 30 thawing degree-days. We recommend the use of this inexpensive non-invasive technique to ensure optimum timing of surveys. As with most monitoring studies, consistency among observers is key to ensuring that the data are comparable across years. We recommend the following to minimize bias due to observer level of skill. 1) To the extent possible, maintain the same observers. 2) New observers should become familiar with relevant aspects of loon biology such as habitat types used for nesting territories and where the nest tends to be located within the territory. 3) New observers should familiarize themselves with past locations of loon territories at each plot, since Red-throated Loons tend to use the same areas year after year. 4) New observers and pilots should practice on a nearby wetland for 1 to 2 hours prior to starting the first set of surveys. 5) Resurvey part of two of plots the following day to obtain detection rates for loons, nests and chicks. Monitoring should be conducted for 3 years every 8 years (i.e. 3 on and 5 off) until development is underway. More frequent monitoring will likely be required during the development phase so that negative impacts can be detected and mitigated in a timely manner. Assuming the above measures are adopted, we view these surveys as a viable way of detecting changes in loon abundance and productivity, and thus recommend continued use of the Red-throated Loon as an indicator of the environmental change that may occur as regional hydrocarbon reserves are developed. (Au)

I, J, L, Q, E
Aerial surveys; Aircraft disturbance; Animal distribution; Animal population; Animal reproduction; Bird nesting; Breakup; Cumulative effects; Design and construction; Detection; Effects monitoring; Environmental impacts; Harbours; Helicopters; Marine pollution; Marine transportation; Offshore oil well drilling; Predation; Quality assurance; Red-throated Loons; Temporal variations; Wetlands; Wildlife habitat

G07, G0812, G0811
Atkinson Point region, N.W.T.; Canadian Beaufort Sea; Husky Lake region, N.W.T.; King Point, Yukon; Toker Point, N.W.T.


Seasonal movement of Pacific Common Eiders breeding in Arctic Canada   /   Dickson, D.L.
Edmonton, Alta. : Canadian Wildlife Service, 2012.
v, 58 p. : maps ; 28 cm.
(Technical report series - Canadian Wildlife Service, no.521)
(PCSP/PPCP contribution, no. 039-11)
ISBN 978-1-100-20239-6
References.
Also available in French.
ASTIS record 77328.
Languages: English
Web: http://www.ec.gc.ca/Publications/default.asp?lang=En&xml=65AD25CF-A8D8-4407-9B5C-7BAB469B3403

Pacific Common Eiders (Somateria mollissima v-nigrum) were tagged with satellite transmitters at a site in central arctic Canada, and their year-round movement was tracked to determine migration routes, timing of movement, and location of moulting, wintering and staging areas. Males departed the nesting colony in the second week of July about a week after median date of start of incubation. Two thirds of the males remained in arctic Canada to moult, primarily in outer Bathurst Inlet, Dolphin and Union Strait and off Cape Parry, while the rest moulted closer to the wintering area, mostly at Kolyuchin Bay in northern Russia. Females remained on the nesting colony until time of hatch, and then moved to marine waters within 45 km of the colony to moult. Males that moulted in Canada departed on fall migration in early October, whereas females departed approximately two weeks later. Fall migration through the Beaufort and Chukchi seas took an average (± SD) of 11 ± 4 days, and none of the eiders staged until they reached the Chukotsk Peninsula in the northern Bering Sea. All but one eider wintered in the polynyas and flaw leads off the southeast coast of Chukotsk Peninsula and St. Lawrence Island; the exception likely wintered north of Nunivak Island, Alaska. Spring migration of birds destined for breeding areas in North America lasted 2.4 ± 0.7 months. Four key spring staging areas were identified: off Chukotsk Peninsula just north of the wintering area, eastern Chukchi Sea, southeast Beaufort Sea, and Lambert Channel in Dolphin and Union Strait. Eiders arrived on their breeding grounds in mid-June. All females returned to within 2 km of the nest site used the previous year (n = 7). By contrast, males were widely distributed across the breeding range in the second year from northeastern Russia to central arctic Canada. Assuming a male follows a female to her breeding area, the dispersal of males in the second breeding season suggests that Pacific Common Eiders from across eastern arctic Russia, northern Alaska and western arctic Canada are all part of the same population that winters in the northern Bering Sea. All females (n = 4), plus those males that returned to Canada to breed in the second year (n = 3), moulted within 24 km of the moult site used the previous year. However, two males that bred in Russia in the second year remained in Russia to moult, thus using an entirely different area. All wintered in the same general location in two consecutive years (n = 5). Due to their tendency to congregate in large numbers in a few select locations, especially during spring migration and winter, Pacific Common Eiders are vulnerable to changes in their environment such as oil spills and altered ice conditions brought about by climate change. (Au)

I, J, L
Animal behaviour; Animal distribution; Animal ecology; Animal live-capture; Animal migration; Animal population; Bird nesting; Common Eiders; Gender differences; Plumage; Radio tracking of animals; Satellite communications; Seasonal variations; Temporal variations; Wildlife habitat; Winter ecology

G0813, G0812, G0811, G06, G07, G04, G0815, G14
Alaska, Northern; Bathurst Inlet, Nunavut; Bathurst, Cape, N.W.T.; Beaufort Sea; Bering Sea; Chukchi Sea; Chukotskiy Poluostrov, Russian Federation; Demarcation Point, Alaska; Dolphin and Union Strait region, Nunavut; Dolphin and Union Strait, Nunavut; Herschel Island, Yukon; Kent Peninsula, Nunavut; Komakuk Beach, Yukon; Lambert Channel, Nunavut; Mackenzie Delta, N.W.T.; St. Lawrence Island, Alaska


Benefiting from a migratory prey : spatio-temporal patterns in allochthonous subsidization of an Arctic predator   /   Giroux, M.-A.   Berteaux, D.   Lecomte, N.   Gauthier, G.   Szor, G.   Bêty, J.
(Journal of animal ecology, v. 81, no. 3, May 2012, p. 533-542, ill., maps)
(PCSP/PPCP contribution, no. 001-12)
References.
ASTIS record 75821.
Languages: English
Web: doi:10.1111/j.1365-2656.2011.01944.x
Libraries: ACU

Summary 1. Flows of nutrients and energy across ecosystem boundaries have the potential to subsidize consumer populations and modify the dynamics of food webs, but how spatio-temporal variations in autochthonous and allochthonous resources affect consumers' subsidization remains largely unexplored. 2. We studied spatio-temporal patterns in the allochthonous subsidization of a predator living in a relatively simple ecosystem. We worked on Bylot Island (Nunavut, Canada), where arctic foxes (Vulpes lagopus L.) feed preferentially on lemmings (Lemmus trimucronatus and Dicrostonyx groenlandicus Traill), and alternatively on colonial greater snow geese (Anser caerulescens atlanticus L.). Geese migrate annually from their wintering grounds (where they feed on farmlands and marshes) to the Canadian Arctic, thus generating a strong flow of nutrients and energy across ecosystem boundaries. 3. We examined the influence of spatial variations in availability of geese on the diet of fox cubs (2003-2005) and on fox reproductive output (1996-2005) during different phases of the lemming cycle. 4. Using stable isotope analysis and a simple statistical routine developed to analyse the outputs of a multisource mixing model (SIAR), we showed that the contribution of geese to the diet of arctic fox cubs decreased with distance from the goose colony. 5. The probability that a den was used for reproduction by foxes decreased with distance from the subsidized goose colony and increased with lemming abundance. When lemmings were highly abundant, the effect of distance from the colony disappeared. The goose colony thus generated a spatial patterning of reproduction probability of foxes, while the lemming cycle generated a strong temporal variation of reproduction probability of foxes. 6. This study shows how the input of energy owing to the large-scale migration of prey affects the functional and reproductive responses of an opportunistic consumer, and how this input is spatially and temporally modulated through the foraging behaviour of the consumer. Thus, perspectives of both landscape and foraging ecology are needed to fully resolve the effects of subsidies on animal demographic processes and population dynamics. (Au)

I, J
Animal behaviour; Animal distribution; Animal ecology; Animal food; Animal migration; Animal population; Animal reproduction; Arctic foxes; Bird nesting; Denning; Food chain; Greater Snow Geese; Isotopes; Lemmings; Predation; Seasonal variations; Spatial distribution; Temporal variations; Wildlife habitat

G0813
Bylot Island, Nunavut


Glacier dynamics and paleoclimatic change during the last glaciation of eastern Ellesmere Island, Canada   /   England, J.
(Canadian journal of earth sciences, v. 33, no. 5, May 1996, p. 779-799, ill., maps)
(PCSP/PPCP contribution, no. 001-96)
References.
ASTIS record 52518.
Languages: English
Web: doi:10.1139/e96-060
Libraries: ACU

A 300 km transect along the east coast of Ellesmere Island fills a major gap in the late Quaternary data base of the Canadian High Arctic. The last glacial maximum (LGM) is marked by prominent moraines and meltwater channels that terminate within 30 km of modern ice margins. Shells in glaciomarine deposits, collected beyond the LGM, indicate deglaciation by more extensive ice prior to 35 ka BP. More than 60 14C dates from glaciomarine sediments provide a chronology for past ice dynamics during the LGM. To the north, while many areas remained ice free due to severe aridity, several glaciers remained in contact with the sea until 7.1 ka BP. Farther south, most glaciers reached the coast and significantly infilled several fiords. This southward increase in glacier extent is due to larger glacial catchment basins and increased precipitation towards storm tracks in northern Baffin Bay. The earliest dates on deglaciation along the transect range from 8.1 to 7.7 ka BP. Initial retreat was controlled by the extent of the marine-based ice margins, which were destabilized by calving. Once landward of the sea, many glaciers stabilized until ~6.5 ka BP. Considerable interfiord variability in glacier dynamics is apparent. A paleoclimatic model is proposed linking past glacier activity in the Canadian High Arctic with the available ice core record. Greenland ice cores show that colder intervals, with depleted delta 18O, were associated with reduced precipitation and storminess, which may have constrained ice buildup prior to ~15 ka BP. In contrast, the abrupt rise in delta 18O after ~15 ka signals the onset of regional warming associated with increased storminess and precipitation (up to 200%). This may have occasioned a late buildup of High Arctic glaciers, which remained close to the last ice limit well into the Holocene. (Au)

A, B, E
Deglaciation; Drainage; Fjords; Geomorphology; Glacial deposits; Glacial epoch; Glacial erosion; Glacial geology; Glacial landforms; Glaciation; Glaciers; Ice caps; Mapping; Moraines; Oxygen-18; Palaeoclimatology; Precipitation (Meteorology); Quaternary period; Radioactive dating; Recent epoch; Sea level; Valleys

G0813, G09
Agassiz Ice Cap, Nunavut; Baffin Bay-Davis Strait; Ellesmere Island waters, Nunavut; Ellesmere Island, Nunavut; Kane Basin, Greenland/Nunavut


Comparison of TIMS (U-Pb) and laser ablation microprobe ICP-MS (Pb) techniques for age determination of detrital zircons from Paleoproterozoic metasedimentary rocks from northeastern Laurentia, Canada, with tectonic implications   /   Scott, D.J.   Gauthier, G.
(Chemical geology, v.131, no. 1-4, Sept. 1996, p. 127-142, ill., maps)
(PCSP/PPCP contribution, no. 005-96)
References.
ASTIS record 45227.
Languages: English
Web: doi:10.1016/0009-2541(96)00030-7

Ages of detrital zircon grains from four samples of Paleoproterozoic metasedimentary rocks from northeastern Laurentia, Canada, analysed by thermal ionisation mass spectrometry (TIMS) and laser-ablation microprobe inductively-coupled plasma quadrupole mass spectrometry (LAM-ICP-MS), are presented and the methods compared. The TIMS results are more precise (±0.1% of age) and in the case of concordant analyses more accurate than the LAM-ICP-MS analyses (±1-2% precision), but both methods show a similar distribution of ages from each sample. Used as complimentary techniques, the combination of TIMS and LAM-ICP-MS analyses yield rapid, precise, and accurate information on the provenance of siliciclastic rocks, offering a powerful tool for the interpretation of the tectonic significance of sedimentary sequences in orogenic belts. The base of the Ramah Group, which sits unconformably on the Nain craton, contains exclusively Archean detritus, with detrital zircon ages corresponding closely to those of dated units in the Nain craton. The Lake Harbour Group, tectonically associated with the Rae craton, was deposited between 1934 ±2 and 1834 ±2 Ma and contains exclusively Paleoproterozoic detritus; 20% of the analysed grains are ~ 2.3 Ga, consistent with an interpretation that the source of some of the detritus was the Rae craton. The Tasiuyak paragneiss, tectonically interleaved between the Rae and Nain cratons, was deposited between 1940 ±2 and 1895 ±2 Ma; most of the analysed grains in the two samples examined are <2.1 Ga, suggesting that neither the adjacent Rae nor Nain cratons were important source areas for this detritus. This is consistent with an interpretation of the Tasiuyak paragneiss as an axially-fed accretionary complex rather than a marginal sequence associated with either the Rae or Nain cratons. (Au)

B
Geological time; Gneiss; Isotopes; Lead; Mass spectrometry; Plate tectonics; Sedimentary rocks; Stratigraphy; Uranium; Zircon

G0813, G0827, G0826
Kimmirut region, Nunavut; Nunatsiavut, Labrador; Ungava, Baie d', Québec


Mineral corona formation during high-p retrogression of granulitic rocks, Ungava Orogen, Canada   /   St-Onge, M.R.   Ijewliw, O.J.
(Journal of petrology, v. 37, no. 3, 1996, p. 553-582, ill., maps)
(PCSP/PPCP contribution, no. 006-96)
References.
This paper is GSC contribution 64694.
ASTIS record 76527.
Languages: English
Web: doi:10.1093/petrology/37.3.553
Libraries: ACU

Crystalline basement exposed in tectonic windows within the Ungava Orogen records a polycyclic Archean granulite-facies to Paleoproterozoic amphibolite-facies history. Amphibolite-facies assemblages comprise garnet coronas around plagioclase, clinopyroxene or cummingtonite coronas on orthopyroxene, hornblende coronas on clinopyroxene ± orthopyroxene, sodic rims on calcic plagioclase, and/or titanite coronas on ilmenite. Petrographic observations and model reactions suggest that growth of coronitic garnet is closely associated with amphibolitization of two pyroxene gneisses. Calcic plagioclase constitutes a key reactant in all garnet-producing reactions and possibly acted as a rate-controlling phase. Multi-equilibrium thermobarometric calculations show good convergence of possible equilibria in the amphibolite fades rocks, indicating that coronitic textures need not imply complete chemical disequilibrium. P-T determinations for the amphibolite-facies gneisses beneath the thrust belt of Ungava Orogen are in the range 7·7-9·8 kbar and 585-723°C. These values are consistent with prograde determinations from pelitic schists within the thrust belt. Estimates of water activity cluster into two populations. High aH2O values are obtained for highly strained basement rocks adjacent to the thrust belt whereas low aH2O values are derived for orthogneiss samples which show no thrust-related fabrics and are distal to the thrust belt. (Au)

B, A
Archaean era; Garnet; Geological time; Gneiss; Hornblende; Metamorphic rocks; Metamorphism (Geology); Mineralogical chemistry; Minerals; Petrography; Petrology; Plate tectonics; Proterozoic era; Quartz; Stratigraphy; Temperature

G0826
Ungava, Péninsule d', Québec


A full-scale field experiment (1978-1995) on the growth of permafrost by means of lake drainage, western Arctic coast : a discussion of the method and some results   /   Mackay, J.R.
(Canadian journal of earth sciences, v. 34, no. 1, Jan. 1997, p. 17-33, ill., maps)
(PCSP/PPCP contribution, no. 007-96)
References.
ASTIS record 62052.
Languages: English
Web: doi:10.1139/e17-002
Libraries: ACU

On 13 August 1978, a lake on the western Arctic coast was artificially drained, in a multidisciplinary experiment on the growth of permafrost on the unfrozen bottom of the drained lake. A bowl-shaped talik (unfrozen basin) with a maximum depth of about 32 m underlay the lake bottom prior to drainage. In the first winter after drainage, downward freezing started on the exposed lake bottom and upward freezing from permafrost beneath the talik. After drainage, the soft lake-bottom sediments hardened from water loss and freeze-thaw consolidation. Gradual thinning of the active layer at many sites was accompanied by ground uplift and the growth of aggradational ice. Downward and upward freezing has resulted in solute rejection, freezing-point depressions, pore-water expulsion from the freezing of the saturated lake-bottom sands, and convective heat transfer from groundwater flow in an open hydrologic system. The increasingly saline intrapermafrost groundwater, flowing at an increasingly negative temperature because of a freezing-point depression, has accelerated the rate of permafrost growth in the interpermafrost zone in the direction of flow. The experiment has demonstrated that the growth of permafrost at the drained lake site, and at other sites with groundwater flow, requires a three-dimensional conductive-convective heat transfer approach. (Au)

C, F, B
Active layer; Bottom sediments; Chemical properties; Drainage; Electrical properties; Flow; Formation; Frost mounds; Frozen ground; Groundwater; Heat transmission; Ice wedges; Interstitial water; Lakes; Moisture content of permafrost; Oxygen-18; Periglacial landforms; Permafrost beneath lakes; Radiocarbon dating; Research; Salinity; Seasonal variations; Soil temperature; Temperature; Temporal variations; Thaw settlement; Thermal expansion; Thermal properties; Thermokarst; Tritium; Water pH; Water quality

G0812
Illisarvik Lake, N.W.T.; Mackenzie Delta, N.W.T.


Live capture of ringed seals in ice-covered waters   /   Kelly, B.P.
(The Journal of wildlife management, v. 60, no. 3, July 1996, p. 678-684, ill.)
(PCSP/PPCP contribution, no. 009-96)
References.
ASTIS record 52699.
Languages: English
Web: doi:10.2307/3802087
Libraries: ACU

Fifteen ringed seals (Phoca hispida), from a small pup to fully mature adults, were captured 1 or more times in nets designed to line seal breathing holes in sea ice. Seals surfacing to breathe triggered the fall of a weight, causing an extension of the nets to drop below the undersurface of the ice and to purse. Nets were monitored acoustically to alert investigators to captures. Seals entered half of the nets set, but escaped in more than half of those instances. Modifications of the net's trigger and diameter should increase the capture rate. (Au)

I, G, N
Animal behaviour; Animal live-capture; Animal tagging; Equipment and supplies; Light; Radio tracking of animals; Sea ice; Seals (Animals); Wildlife management

G07, G0815, G04
Alaskan Beaufort Sea; Barrow Strait, Nunavut; Chukchi Sea; Prudhoe Bay, Alaska


Ringed seal diving behavior in the breeding season   /   Kelly, B.P.   Wartzok, D.
(Canadian journal of zoology, v. 74, no. 8, Aug. 1996, p.1547-1555, ill.)
(PCSP/PPCP contribution, no. 010-96)
References.
ASTIS record 43145.
Languages: English
Web: doi:10.1139/z96-169
Libraries: ACU

The behavior of 14 ringed seals (Phoca hispida) diving under shore-fast sea ice was monitored acoustically during the spring breeding season. Frequent dives with extended periods at depth by subadult and adult seals, including lactating females, were interpreted to be foraging dives. Median dive durations were less than 10.0 min for all seals, and the maximal observed duration was 26.4 min. The maximal observed dive depth, 222 m, was limited by water depth in the study area. Modal dive depths were between 10 and 45 m for breeding-age males and between 100 and 145 m for subadult females. Body mass was a better predictor of maximal dive duration (r² = 0.94) than was age, but maximal durations were shorter than were predicted using measures of oxygen stores and presumed metabolic rates. There was no consistent relationship between light level and the frequency or depth of dives. (Au)

I, N, T, F
Animal behaviour; Animal distribution; Animal physiology; Animal reproduction; Animal tagging; Diving (Animals); Grazing; Metabolism; Radio tracking of animals; Seals (Animals)

G0815
Barrow Strait, Nunavut; Resolute Passage, Nunavut


An overview of the U-Pb geochronology of the Paleoproterozoic Torngat Orogen, northeastern Canada   /   Scott, D.J.
(Precambrian research, v. 91, no. 1-2, Aug. 1998, p. 91-107, ill. 1 map)
(PCSP/PPCP contribution, no. 013-96)
References.
ASTIS record 45088.
Languages: English
Web: doi:10.1016/S0301-9268(98)00040-0
Libraries: ACU

The Paleoproterozoic Torngat Orogen, northern Labrador and northeastern Quebec, Canada, is the result of oblique collision between the Nain (North Atlantic) and Rae cratons. A comprehensive set of U-Pb ages allows the chronology of events to be closely bracketed. Subduction occurred below the Nain craton from ca 1910-1870 Ma, and collision between the cratons may have occurred between 1869 and 1844 Ma. Sinistral deformation continued along the intervening Abloviak Shear zone until ca 1824 Ma, and convergence was ultimately impeded by the partial subduction of the southern Rae craton. Post-collisional isostatic uplift of the southern Rae craton initiated deformation in the Komaktorvik zone ca 1798 Ma. A prominent bend in the Abloviak Shear zone may be the result of differential uplift of the western side of the orogen in the south. Sinistral strike-slip and east- as well as west-side-up deformation continued episodically in the Komaktorvik zone until at least 1710 Ma. The tectonic development of the orogen can be explained in terms of modern plate tectonic processes. (Au)

B
Archaean era; Deformation; Geological time; Magmatism; Metamorphism (Geology); Plate tectonics; Proterozoic era; Radioactive dating; Sedimentation; Stratigraphy; Structural geology; Volcanism; Zircon

G0827, G0826
Nunatsiavut, Labrador; Nunavik, Québec


The use of remote sensing to evaluate shorebird habitats and populations on Prince Charles Island, Foxe Basin, Canada   /   Morrison, R.I.G.
(Arctic, v. 50, no. 1, Mar. 1997, p. 55-75, 1 ill., 1 map)
(PCSP/PPCP contribution, no. 020-96)
References.
ASTIS record 39923.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic50-1-55.pdf
Web: doi:10.14430/arctic1091
Libraries: ACU

Landsat-5 Thematic Mapper imagery was used to produce a 17-habitat classification of Prince Charles Island, Foxe Basin, Northwest Territories, through a combination of supervised and unsupervised approaches. Breeding shorebirds and habitats were surveyed at 35 study plots in July 1989. Habitat-specific breeding densities calculated from these observations were used to estimate total populations of breeding shorebirds on the island based on areas of habitat derived from the classified image. Breeding densities were further modelled in two ways: first, to adjust for distance from the coast, where regression analyses found a significant relationship between distance and density, and second, to include only those pixels of areas considered suitable for breeding, using results of a proximity analysis to determine habitat associations between known breeding locations (pixels) and other habitats. Six species of shorebirds were found breeding on Prince Charles Island, with a combined population (after modelling) estimated at 294 000 pairs. Comparison of breeding densities and estimated populations of shorebirds with those recorded at other arctic locations indicated that Prince Charles Island supports highly significant numbers of shorebirds, especially white-rumped sandpipers and red phalaropes. Comparison of reference areas of known habitat with those on the classified image indicated classification accuracy averaged over 90%. Remote sensing appears to offer a reliable method for assessing habitats and regional breeding populations of birds in at least some areas, providing that classification methods are carried out in a carefully controlled manner. Use of the method over broad areas of the Arctic would require considerable work to recalibrate imagery for different geographic regions. (Au)

I, S, H, A
Animal behaviour; Animal distribution; Animal population; Bird nesting; Land classification; Mapping; Mathematical models; Plants (Biology); Remote sensing; Salt marshes; Satellite photography; Shorebirds; Wetlands; Wildlife habitat

G0813, G0812, G0811, G06
Alaska; N.W.T.; Nunavut; Prince Charles Island, Nunavut; Yukon


Daily energy expenditure and water turnover of shorebirds at Alert, Ellesmere Island, N.W.T.   /   Morrison, R.I.G.   Davidson, N.C.   Piersma, T.
Ottawa : Environment Canada, 1997.
8 p. : ill. ; 28 cm.
(Progress notes - Canadian Wildlife Service, no. 211)
(PCSP/PPCP contribution, no. 021-96)
References.
ASTIS record 42290.
Languages: English
Libraries: ACU

Shorebirds have adapted to their energetically demanding lifestyles through metabolic, organ-level adjustments reflected by a high basal metabolic rate (BMR). BMRs may vary during the year, increasing, for instance, during the energy-demanding period associated with build-up of mass before migration. For birds inhabiting apparently extreme environments, such as those found in the most northern part of the Canadian High Arctic, estimates of energetic costs of existence during the breeding season are of particular interest. Few studies have been carried out to measure field metabolic rates directly. This note reports preliminary results of such studies at Alert, on the north coast of Ellesmere Island, for two long-distance migratory shorebirds the Ruddy Turnstone Arenaria interpres and Red Knot Calidris canutus. Studies undertaken in 1990 and 1994 show that the birds have high field metabolic rates, indicating a high energy demand; these rates, however, are comparable to or less than those experienced in other parts of the Canadian Arctic, in the Siberian Arctic, or on the European wintering grounds to which the species migrate. (Au)

I, J
Animal physiology; Energy budgets; Metabolism; Shorebirds

G0813
Alert region, Nunavut; Alert, Nunavut


Geology, U-Pb, and Pb-Pb geochronology of the Lake Harbour area, southern Baffin Island : implications for the Paleoproterozoic tectonic evolution of northeastern Laurentia   /   Scott, D.J.
(Canadian journal of earth sciences, v. 34, no. 2, Feb. 1997, p. 140-155, ill., maps)
(PCSP/PPCP contribution, no. 022-96)
References.
ASTIS record 52423.
Languages: English
Web: doi:10.1139/e17-012
Libraries: ACU

Geological and geochronological results of an investigation of the Paleoproterozoic siliciclastic and carbonate supracrustal rocks of the Lake Harbour Grop (LHG) and surrounding tonalitic gneisses on southern Baffin Island are presented. Conventional U-Pb geochronology of monazite from rocks of the LHG suggest that penetrative deformation of these rocks occurred prior to, or during, peak metamorphic conditions of ca. 1845-1840 Ma. Conventional U-Pb zircon results indicate that much of the tonalitic gneiss ranges in age from 1842+5/-3 to 1827+13/-9 Ma. The tonalitic gneisses and Lake Harbour Group units were tectonically imbricated by ca. 1805 Ma, and are part of a southwest-verging thrust belt interpreted from regional considerations to represent the northern continuation of the Ungava Orogen. The present results indicate that current tectonic models for the evolution of northeastern Laurentia that involve a dominantly Archean southeastern Rae province require revision. It is proposed that much of the metaigneous material that lies between the Archean Superior and Nain cratons represents a composite subduction-related domain. (Au)

B
Deformation; Geological time; Gneiss; Magmatism; Metamorphism (Geology); Proterozoic era; Stratigraphy; Structural geology; Zircon

G0813, G0826, G0827
Baffin Island, Nunavut; Hudson Strait region, Nunavut/Québec; Joy River region, Nunavut; Lake Harbour region, Nunavut; Markham Bay region, Nunavut; Meta Incognita Peninsula, Nunavut; Nunatsiavut, Labrador; Soper Lake region, Nunavut; Ungava, Baie d', region, Québec


Arctic cyanobacteria and limnological properties of their environment : Bylot Island, Northwest Territories, Canada (73°N, 80°W)   /   Vézina, S.   Vincent, W.F.
(Polar biology, v. 17, no. 6, May 1997, p. 523-534, ill., maps)
(PCSP/PPCP contribution, no. 025-96)
References.
ASTIS record 52437.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/105.pdf
Web: doi:10.1007/s003000050151
Libraries: ACU

Cyanobacteria were a major constituent of phototrophic communities in the lakes, ponds and streams of Bylot Island, in the Canadian high Arctic. The waters spanned a range of temperatures (1.8-16.8°C in late July), pH regimes (6.2-9.2) and conductivities (1.5-1700 µS/cm) but nutrient concentrations were consistently low (<1 µg dissolved reactive P/l at all sites; < 10 µg NO3-N/l at most sites). Picoplanktonic species (Synechococcus spp.) were often the numerical dominants in the plankton, and periphytic filamentous species (Oscillatoriaceae) commonly formed thick (5-50 mm) benthic mats. Bloom-forming species of cyanobacteria were either absent or poorly represented even in Chl a-rich ponds. The total community biomass ranged from 0.1 to 29.8 µg Chl a/l in the plankton and from 1.1 to 34:8 µg Chl a/cm² in the benthos. The in vivo absorbance characteristics of isolates from these environments indicated a genetically diverse range of species in each group of Arctic cyanobacteria. Growth versus irradiance relationships were determined for each of the isolates and similarly revealed large genetic differences (maximum growth rates from 0.17 to 0.61/day), even between morphologically identical taxa. A comparison of nutrients, pigment concentrations and species composition underscores the strong similarities between freshwater ecosystems in the north and south polar zones. (Au)

H, F, J, A
Algae; Benthos; Biomass; Chemical properties; Chlorophyll; Cyanophyceae; Fresh-water ecology; Lakes; Light; Moraines; Physical properties; Phytoplankton; Plant distribution; Plant growth; Plant nutrition; Plant taxonomy; Rivers; Temperature; Thermokarst; Tundra ponds; Wetlands

G0813, G01
Antarctic regions; Bylot Island, Nunavut; Navy Board Inlet region, Nunavut; Polar regions


Underwater ultraviolet radiation : development of spectral models for northern high latitude lakes   /   Laurion, I.   Vincent, W.F.   Lean, D.R.S.
(Photochemistry and photobiology, v. 65, no. 1, 1997, p. 107-114, ill., maps)
(PCSP/PPCP contribution, no. 026-96)
References.
ASTIS record 55568.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/106.pdf

The penetration of solar ultraviolet radiation (UVR) and photosynthetically available radiation (PAR) was measured in a range of subarctic takes in the forest-tundra zone of northern Québec. The diffuse attenuation coefficients for PAR (KdPAR) were highly correlated (r² = 0.78) with dissolved organic carbon (DOC) concentration and only weakly correlated with suspended particulate material as measured by chlorophyll a (r² = 0.48) or beam transmittance (r² = 0.29). Colored dissolved organic matter (CDOM) was also largely responsible for the between-lake differences in spectral attenuation of UVR. The diffuse attenuation coefficient for UVR (Kd) was a nonlinear function of wavelength (lambda) and was accurately described by the model Kd(lambda) = Kd440 exp(-S (lambda - 440). The slope coefficient S was relatively constant among lakes (mean = 0.0151/nm, CV = 7%), whereas Kd440 was a linear function of several CDOM-related variables and best estimated by CDOM fluorescence (r² = 0.98). Numerical analysis of spectra for high (subarctic) and low (Arctic) DOC lakes showed that the evaluation of the model parameters Kd440 and S was insensitive to the bandpass characteristics (2-8 nm) of different underwater radiometers. The Kd(lambda) model was then used to develop a nondimensional index of relative spectral composition (RI) to characterize different water masses as a function of dissolved organic matter (DOC and CDOM fluorescence). Below about 4 mg DOC/L there is a sharp nonlinear rise in this index with decreasing DOC. These results show that CDOM controls the spectral composition of underwater UVR in northern high-latitude lakes and that the UVR/PAR balance in many of these waters is sensitive to minor changes in CDOM content. (Au)

F, H, J, E
Carbon; Chlorophyll; Climate change; Colored dissolved organic matter; Dissolved organic carbon; Fluorometry; Fresh-water ecology; Instruments; Lakes; Logistics; Mathematical models; Measurement; Optical properties; Ozone; Photosynthesis; Phytoplankton; Rivers; Solar radiation; Spectroscopy; Suspended solids; Ultraviolet radiation; Upper atmosphere

G0813, G0826
Baleine, Grande rivière de la, region, Québec; Bienville, Lac, (55 05 N, 72 40 W) region, Québec; Char Lake, Nunavut; Eau Claire, Lac à l', region, Québec; Kuujjuarapik region, Québec; Meretta Lake, Nunavut; North Lake, Nunavut; Skeleton Lake, Nunavut


Sensitivity of high-latitude freshwater ecosystems to global change : temperature and solar ultraviolet radiation   /   Vincent, W.F.   Pienitz, R.
(Geoscience Canada, v. 23, no. 4, Dec. 1996, p. 231-236, ill.)
(PCSP/PPCP contribution, no. 027-96)
References.
This edition of Geoscience Canada contains papers from the Geological Association of Canada Nuna Conference, Nunavut Environment Assessment Transect (NEAT), Pond Inlet, N.W.T., 14-18 June 1996.
Abstract also in French.
ASTIS record 52674.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/104.pdf
Libraries: ACU

Freshwater ecosystems are a major component of the northern environment. The application of new limnological technologies and approaches to these ecosystems is producing a revised perspective on their structure and dynamics, and is leading to insights into their potential response to global change processes. The planktonic communities of northern lakes are dominated by microbial food webs, with components that are highly sensitive to changes in temperature. North-south transects in Quebec, Yukon and the Northwest Territories show that lakes beyond the northern tree line have concentrations of UV-screening dissolved organic carbon less than 5 mg/l, rendering them vulnerable to changes in incident UVB and to climatic effects on catchment hydrology. The coupling of studies on the modern-day limnology of northern freshwater ecosystems with paleolimnological approaches will allow the interpretation of short-term changes in these systems within the context of their historical variability. (Au)

F, E, J, H, I, G, B
Algae; Atmospheric temperature; Bacteria; Biological productivity; Biomass; Bottom sediments; Carbon; Carbon dioxide; Climate change; Diatoms; Dissolved organic carbon; Environmental impacts; Food chain; Fresh-water ecology; Hydrology; Ice cover; Invertebrates; Lake stratification; Lakes; Microorganisms; Nitrogen; Oligotrophic lakes; Palaeoecology; Phosphorus; Photosynthesis; Phytoplankton; Precipitation (Meteorology); Primary production (Biology); Protozoa; Rivers; Runoff; Snow cover; Soil moisture; Solar radiation; Taiga ecology; Temperature; Treeline; Tundra ecology; Ultraviolet radiation; Water; Watersheds; Wetlands; Zooplankton

G0813, G0826, G0812, G0811
N.W.T.; Nunavik, Québec; Nunavut; Québec; Yukon


Distribution and abundance of birds on western Victoria Island, 1992 to 1994   /   Cornish, B.J.   Dickson, D.L.
Edmonton, Alta. : Canadian Wildlife Service, Prairie and Northern Region, 1996.
xii, 78 p. : maps ; 28 cm.
(Technical report series - Canadian Wildlife Service, no.253)
(PCSP/PPCP contribution, no. 029-96)
ISBN 0-662-24506-7
Appendices.
References.
Report date: March 1996.
ASTIS record 73813.
Languages: English
Libraries: AEU

A three-year study to determine the distribution and abundance of birds nesting on western Victoria Island was initiated jointly by the Canadian Wildlife Service and Inuvialuit in 1992. Although emphasis was on the King Eider, which is an important food source for the people of Holman, observations were recorded for all bird species: There were two components to the study: aerial surveys conducted over much of the western half of the island, and surveys on the ground at a site in the Kagloryuak River valley. Aerial Surveys: Aerial surveys for breeding birds were conducted between 16 June and 1 July each year from 1992 to 1994. The study area in 1992 and 1994 was northwest Victoria Island (82 749 km²), but in 1993 was expanded to include southwest Victoria Island (an additional 22 104 km²). Straight-line transects were flown by helicopter across each of six strata (eight in 1993), and two observers recorded all birds seen within 200 m of each side of the aircraft. A total of 27 bird species were identified during the aerial surveys, the most abundant of which was the King Eider. There were an estimated 33 000 King Elders on northwest Victoria Island in the first two years of surveys, and 51 000 in the third year. Southwest Victoria Island had an estimated 11 000 King Eiders in the one year that it was surveyed. The number of breeding pairs did not vary significantly among years. The higher population estimate in the third year was due to the presence of more elders in flocks of greater than four birds. The highest densities of King Eiders occurred in the Kagloryuak River valley and near Tahiryuak Lake. The results of this study as well as other research (Alexander et al 1994; Suydam et al in prep.) suggest a decline in the western Arctic King Eider population over the past two to three decades. Other common waterfowl species were the Canada Goose, Brant, Tundra Swan and Oldsquaw. Population estimates for Canada Geese in northwest Victoria Island ranged from approximately 16 000 to 25 000, with an additional 19 000 in southwest Victoria Island. We estimated between 900 and 1200 Brant, 3200 to 3800 Tundra Swans and 4600 to 7800 Oldsquaw in northwest Victoria Island. Population estimates for these species in southwest Victoria Island were approximately 200 Brant, 4200 Tundra Swans and 1800 Oldsquaw. The strata encompassing the Kagloryuak River valley and area from Tassijuak Lake south to Coronation Gulf supported the highest densities of Canada Geese and Tundra Swans. Brant observations were primarily in only two strata, the Kag1oryuak River valley and Prince Albert Peninsula, while Oldsquaws were scattered across the study area. A comparison of our population estimates to the results of similar aerial surveys in 1980 (Allen 1982; McLaren and Alliston 1981) as well as other studies (Parmelee et al 1967; Lok and Vink 1986) suggests that Canada Geese may be expanding their range northward on Victoria Island, while numbers of Brant and Oldsquaw appear to be declining. Pacific Loons were the most common loons, representing between 63 and 81% of the loons identified to species. The population estimate in northwest Vicroria Island ranged from 2500 to 5300 loons, with an additional 1200 in southwest Victoria Island. Densities of this species were generally highest in the Kagloryuak River valley. Other species observed were Yellow-billed and Red-throated loons. The only abundant raptor species observed during the aerial surveys were Rough-legged Hawks and Snowy Owls. Population estimates for Rough-legged Hawks in northwest Victoria Island ranged from approximately 1000 to 2000 birds, while fewer than 100 were estimated for the southwest portion of the study area. Numbers of Snowy Owls varied dramatically over the three years of the study. The 1994 population estimate was less than one-third the 1993 estimate of 3566 ± 1494 owls in northwest Victoria Island. Both Rough-legged Hawks and Snowy Owls were most abundant on Prince Albert Penin sula. Six Peregrine Falcons and 1 Gyrfalcon were observed during our surveys. Four of the 6 Peregrine Falcon sightings were on the cliffs of Diamond Jenness Peninsula which concurs with previous reports of the importance of these cliffs for nesting Peregrine Falcon (Allen 1982; McLaren and Alliston 1981). Three species of jaegers were observed in the study area: Pomarine, Parasitic and Long-tailed jaegers. The most abundant jaeger during our surveys, as well as the 1980 surveys by McLaren and Alliston (1981), was the Pomarine Jaeger. Like the Snowy Owl, Pomarine Jaegers experienced a major decline in numbers in 1994, falling from an estimated 7340 ± 490 in 1993 to 1236 ± 267 in 1994. The decline in both species is attributed to a crash in lemming populations, their primary prey. Glaucous Gulls were widespread and fairly evenly distributed in the study area. They occurred in greatest abundance in 1992 when an estimated 11 525 ± 4718 occurred in northwest Victoria Island. The only other common gull species was the Sabine's Gull. We estimated about 1500 Sabine's Gulls each year on northwest Victoria Island, almost 90% of which were in the Kagloryuak River valley or near Tahiryuak Lake. Very few were seen in southwest Victoria Island. Arctic Terns were more widely distributed, and population estimates ranged from about 2300 to 3700 birds in northwest Victoria Island, with an additional 975 in southwest Victoria Island. Thayer's Gulls were locally abundant in northwest Prince Albert Sound where we found six colonies on cliffs on the islands and along the coast. One other colony was found in Minto Inlet. Terrestrial Surveys: Between 10 and 22 July in 1992 and from 20 June to 2 July in 1993, we conducted bird surveys on the ground in a 50 km² study area in the Kagloryuak River valley. This area was selected because of its potential to support high densities of nesting King Eiders. The objective of the terrestrial surveys was to obtain further information on bird abundance , nesting distribution and habitat use in this area. Bird observations were recorded during 87 hours of surveying in 1992. In 1993, we surveyed a total of 50.8 km along 12 transects. The Kagloryuak River valley has a rich and diverse bird life relative to the rest of western Victoria Island. During the terrestrial surveys, we recorded 34 species of birds and found evidence of nesting (unfledged young or a nest with eggs) for 18 species. These surveys allowed us to identify the smaller bird species, including 10 shorebird and 5 passerine species, which we were unable to accurately distinguish during the aerial surveys. The most common bird recorded was the Lapland Longspur, with a density in 1993 of 58 birds/km², but shorebird populations were also abundant. Eight shorebird species together comprised 53% of total birds seen. Over the two years of surveys, the most common shorebirds were Semipalmated Sandpiper, Pectoral Sandpiper, Red Phalarope, White-rumped Sandpiper, Lesser Golden Plover and Stilt Sandpiper. We recorded seven waterfowl species during these surveys, the most abundant being the Canada Goose, King Eider and Tundra Swan. All three species of jaegers were observed, but Pomarine Jaegers predominated. Thirteen habitat types were recognized and described in the Kagloryuak River valley study area. Well-vegetated graminoid-dominated lowlands were the most abundant habitats. Ponded lowland habitats of this type received the heaviest use by birds and had the greatest species richness. Similar observations were recorded by McLaren and Alliston (1981). The gently sloped upland habitats supported a less diverse bird population, but were favoured by some species. (Au)

I, J
Aerial surveys; Animal distribution; Animal population; Bird nesting; Brant; Canada Geese; Ducks; Geese; Gulls; Jaegers; King Eiders; Long-tailed Ducks; Loons; Raptors; Sea birds; Snowy Owls; Temporal variations; Tundra Swans; Waterfowl; Wildlife habitat

G07, G0812
Diamond Jenness Peninsula, N.W.T.; Kagloryuak River region, N.W.T./Nunavut; Prince Albert Peninsula, N.W.T.; Tahiryuak Lake region, N.W.T.; Victoria Island, N.W.T./Nunavut; Wollaston Peninsula, N.W.T./Nunavut


Cyanobacterial dominance of polar freshwater ecosystems : are high-latitude mat-formers adapted to low temperature?   /   Tang, E.P.Y.   Tremblay, R.   Vincent, W.F.
(Journal of phycology, v. 33, no. 2, Apr. 1997, p. 171-181, ill.)
(PCSP/PPCP contribution, no. 033-96)
References.
ASTIS record 52432.
Languages: English
Web: doi:10.1111/j.0022-3646.1997.00171.x
Libraries: ACU

Although it is generally believed that cyanobacteria have high temperature optima for growth (> 20° C), mat-forming cyanobacteria are dominant in many types of lakes, streams, and ponds in the Arctic and Antarctic. We studied the effect of temperature on growth (µ) and relative pigment composition of 27 isolates of cyanobacteria (mat-forming Oscillatoriaceae) from the Arctic, subarctic, and Antarctic to investigate whether they are a) adapted to the low temperature (ie, psychrophilic) or b) tolerant of the low temperature of the polar regions (ie, psychrotrophic). We also derived a parabolic function that describes both the rise and the decline of cyanobacterial growth rates with increasing temperature. The cyanobacteria were cultured at seven different temperatures (5°-35° C at 5° C intervals), with continuous illumination of 225 µmol photons/m²/s. The parabolic function fits the µ-temperature data with 90% confidence for 75% of the isolates. Among the 27 isolates of cyanobacteria studied, the temperature optima (Topt) for growth ranged from 15° to 35° C, with an average of 19.9° C. These results imply that most polar cyanobacteria are psychrotrophs, not psychrophiles. The cyanobacteria grew over a wide temperature range (typically 20° C) but growth rates were low even at Topt (average µ max of 0.23 ±0.069/d). Extremely slow growth rates at low temperature and the high temperature for optimal growth imply that the cyanobacteria are not adapted genetically to cold temperatures, which characterize their ambient environment. Other competitive advantages such as tolerance to desiccation, freeze-thaw cycles, and bright, continuous solar radiation may contribute to their dominance in polar aquatic ecosystems. (Au)

H, E, F, J
Adaptation (Biology); Algae; Atmospheric temperature; Cyanophyceae; Effects of temperature on plants; Fresh-water ecology; Ice shelves; Lakes; Mathematical models; Photosynthesis; Plant distribution; Plant growth; Rivers; Tundra ponds

G0813, G01, G06, G0826
Alaska, Northern; Bylot Island, Nunavut; Devon Island, Nunavut; Eau Claire, Lac à l', region, Québec; Kuujjuarapik, Québec; Meretta Lake, Nunavut; Polar regions; Resolute region, Nunavut; Toolik Lake region, Alaska


Long-term environmental monitoring in Arctic lakes and ponds using diatoms and other biological indicators   /   Smol, J.P.   Douglas, M.S.V.
(Geoscience Canada, v. 23, no. 4, Dec. 1996, p. 225-230, ill.)
(PCSP/PPCP contribution, no. 034-96)
References.
This edition of Geoscience Canada contains papers from the Geological Association of Canada Nuna Conference, Nunavut Environment Assessment Transect (NEAT), Pond Inlet, N.W.T., 14-18 June 1996.
Abstract also in French.
ASTIS record 52547.
Languages: English
Libraries: ACU

Long-term monitoring data are required to make effective environmental decisions. Unfortunately, such direct measurements are rarely available. Long-term data are especially sparse in arctic tundra regions, where logistic concerns of ten preclude the implementation of standard monitoring programs. However, paleolimnological techniques, such as the use of diatom assemblages preserved in dated lake and pond sediment profiles, can provide proxy data of past environmental changes. This paper summarizes some of the ways biological-based paleolimnological techniques can be used in arctic tundra environments to monitor environmental changes. Specific examples include studies of climatic change, airborne contaminants, and local disturbances. (Au)

F, B, J, H, E, G, I
Acid rain; Algae; Atmospheric temperature; Bacteria; Bottom sediments; Chemistry; Climate change; Diatoms; Diptera; Effects monitoring; Environmental impacts; Eutrophic lakes; Fresh-water ecology; Geological time; Ice cover; Lake ice; Lakes; Lead; Palaeoecology; Palaeontology; Palynology; Pollution; Radiocarbon dating; Radionuclides; Sedimentation; Sediments (Geology); Snow; Snow cover; Temperature; Temporal variations; Thickness; Tundra ecology; Water; Water pH; Water quality

G081, G0813
Canadian Arctic; Fosheim Peninsula, Nunavut; Herschel, Cape, Nunavut; Pond Inlet (Hamlet), Nunavut; Taconite Inlet region, Nunavut


Cryostratigraphy, paleogeography, and climate change during the early Holocene warm interval, western Arctic coast, Canada   /   Burn, C.R.
(Canadian journal of earth sciences, v. 34, no. 7, July 1997, p. 912-925, ill., maps)
(PCSP/PPCP contribution, no. 001-97)
References.
ASTIS record 62054.
Languages: English
Web: doi:10.1139/e17-076
Libraries: ACU

Botanical and cryostratigraphic records from northwest Canada indicate that the climate of the early Holocene was considerably warmer than today: tree line was over 100 km farther north; and a thaw unconformity, dating from 8000 14C years BP, formed at the base of an active layer 2.5 times thicker than at present. Numerous thermokarst-lake basins formed in the preceding millennia. Both the botanical and cryostratigraphic indices described are products of summer conditions. Previous reconstructions of early Holocene climate have not assessed the significance of paleocoastal location on the seasonality and extent of apparent climate warming. At present, there is a steep gradient in growing-season conditions between cooler sites on the Beaufort Sea coast and warmer, inland locations. Winter conditions are more uniform because both sea and land are snow-covered. Coastal retreat in the region has been rapid, due to sea level rising over a gently sloping shelf containing readily erodible sediments. The coastline has moved about 100 km southward during the Holocene. The increasing proximity to the coast, through time, of points currently within 100 km of the sea may account for between one and two thirds of the cooling in summer climate experienced there since the mid-Holocene. (Au)

B, E, A, F, H, C
Active layer; Beach erosion; Bottom sediments; Climate change; Climatology; Coast changes; Frozen ground; Growing season; Lakes; Palaeobotany; Palaeoclimatology; Palaeogeography; Palynology; Plant distribution; Recent epoch; Sea level; Seasonal variations; Snow; Snow cover; Spruces; Stratigraphy; Thawing; Thermokarst; Thickness; Treeline; Winds

G0812, G0811
Garry Island, N.W.T.; Hanging Pond, Yukon; Hooper Island (69 41 N, 134 53 W), N.W.T.; Illisarvik Lake, N.W.T.; Inuvik region, N.W.T.; Mackenzie Delta, N.W.T.; Mackenzie River region, N.W.T.; Mayo region, Yukon; Pelly Island, N.W.T.; Richards Island, N.W.T.; Tuktoyaktuk Peninsula, N.W.T.


Factors affecting nesting success in Greater Snow Geese : effects of habitat and association with Snowy Owls   /   Tremblay, J.-P.   Gauthier, G.   Lepage, D.   Desrochers, A.
(The Wilson bulletin (Wilson Ornithological Society), v.109, no. 3, 1997, p. 449-461)
(PCSP/PPCP contribution, no. 002-97)
References.
Not seen by ASTIS.
ASTIS record 43181.
Languages: English
Libraries: ACU

We examined how habitat features affected nesting success of Greater Snow Geese (Chen caerulescens atlantica) on Bylot Island, Northwest Territories, Canada, under high (1993) vs low (1994) nesting success and colonial vs isolated nesting (1994 only). Because Snow Geese nested in association with Snowy Owls (Nyctea scandiaca) in 1993, we also examined the relationship between nesting success and distance from owl nests. Predation, especially by Arctic foxes (Alopex lagopus), was the main cause of nesting failure on Bylot Island. In 1993, goose nests near an owl nest had better success than those farther away, and they also tended to be initiated earlier. Few habitat features were related to nesting success, although nests located in pond habitat had lower success than those in wet meadows or moist tundra. In 1994, Snowy Owls were absent, and goose nesting success was much lower than in 1993 (23-42% vs 90%). Isolated nests located on hillsides had higher success than those located in lowlands. In contrast, colonial nests were more successful in lowland wet meadows, where tall willow bushes (Salix lanata) were present, than in either moist tundra or hillsides. In the latter habitat, nests associated with Cassiope tetragona, a plant that typically grows in depressions between hummocks, had higher success than those associated with other vegetation. We conclude that nesting in association with raptors, such as Snowy Owls, that maintain a predator-free area around their nest, was probably a dominant factor affecting Greater Snow Goose nesting success. In the absence of owls, isolated nests had higher success in hilly habitats than in lowlands, whereas colonial nests in tall willows were most successful. (Au)

I, J
Animal behaviour; Animal ecology; Animal mortality; Animal population; Animal reproduction; Arctic foxes; Bird nesting; Greater Snow Geese; Predation; Snowy Owls; Spatial distribution; Wildlife habitat

G0813
Bylot Island, Nunavut


King and Common Eiders of the western Canadian Arctic   /   Dickson, D.L.
Edmonton, Alta. : Canadian Wildlife Service, 1997.
75 p. : ill., maps ; 28 cm.
(Occasional paper - Canadian Wildlife Service, no. 94)
(PCSP/PPCP contribution, no. 003-97)
ISBN 0-662-25471-6
Reference.
ASTIS record 40549.
Languages: English
Libraries: ACU

Two eider populations breed in the western Canadian Arctic and winter in the Bering Sea: the Pacific subspecies of the Common Eider, Somateria mollissima v-nigra, and the western Arctic population of the King Eider, S. spectabilis. Both eiders are harvested primarily in the spring by the Aboriginal people of northern communities and to a small extent in fall by sport hunters. Some eggs of the colonially nesting Common Eider are also taken. Compared with other harvested waterfowl, there are few available data on even the most basic aspects of the biology of these two eider populations, including their status and nesting distribution. This is largely because they inhabit remote areas and thus are logistically difficult and expensive to study. However, several recent events have forced wildlife managers to try to address some of the information gaps. ... The papers contributed here represent information collected on Common and King eiders in the western Canadian Arctic since Barry's (1986) mid-1980s review of what was known. These data contribute to our knowledge must continue to grow if we truly intend to protect and conserve eiders in future. (Au)

I, T, N, J
Animal behaviour; Animal distribution; Animal migration; Animal mortality; Animal population; Bird nesting; Eiders; Hunting; Inuit; Subsistence; Wildlife management

G0813, G0812, G0811, G06
Alaska, Northern; Banks Island, N.W.T.; Barrow, Point, Alaska; Inuvialuit Settlement Region, N.W.T./Yukon; Nunavut; Victoria Island, N.W.T./Nunavut; Yukon North Slope


Phylogeography and postglacial dispersal of lake trout (Salvelinus namaycush) in North America   /   Wilson, C.C.   Hebert, P.D.N.
(Canadian journal of fisheries and aquatic sciences, v. 55, no. 4, April 1998, p.1010-1024, ill., maps)
(PCSP/PPCP contribution, no. 010-97)
References.
ASTIS record 47387.
Languages: English
Web: doi:10.1139/cjfas-55-4-1010
Libraries: ACU

We used restriction fragment length polymorphism (RFLP) analysis of mitochondrial DNA (mtDNA) diversity to assess the complex postglacial history of lake trout (Salvelinus namaycush) and test existing dispersal hypotheses. A pilot survey with 30 restriction enzymes was carried out on lake trout from 16 geographically representative populations to determine phylogenetically informative characters. Subsequent screening of 1416 lake trout from 93 populations across the species' range with nine variable restriction enzymes showed that lake trout from at least five glacial refugia contributed to extant populations. Three major mtDNA lineages were observed, with sufficient differences to suggest their divergence during the mid-Pleistocene. Geographic and genetic differences within two lineages suggested further vicariant divergence caused by Wisconsinan glacial advances. In contrast with more southern freshwater species, no correlation was observed between the geographic proximity of glacial refugia and relatedness of mtDNA lineages. Current distributions of refugial lineages are readily explained by consideration of timing and connections of proglacial lakes. These lakes facilitated large-scale dispersal from multiple refugia, particularly enabling long-distance dispersal from the Mississippian and northwestern refugia. Proglacial lakes also enabled extensive secondary contact among refugial groups, resulting in high levels of intrapopulation mtDNA diversity within their former boundaries. (ASTIS)

I, B, A, F
Animal distribution; Animal population; Enzymes; Genetics; Glaciation; Lake trout; Lakes; Pleistocene epoch; Refugia

G08
Canada; Canadian Arctic


Larger clutch size increases fledging success and offspring quality in a precocial species   /   Lepage, D.   Gauthier, G.   Desrochers, A.
(Journal of animal ecology, v. 67, no. 2, Mar. 1998, p. 210-216, ill.)
(PCSP/PPCP contribution, no. 011-97)
References.
ASTIS record 47503.
Languages: English
Web: doi:10.1046/j.1365-2656.1998.00182.x
Libraries: ACU

1. We tested the hypothesis that the ability of parents to raise viable offspring limits clutch size in the greater snow goose (Anser caerulescens atlanticus L.), a precocial bird. 2. We manipulated clutch size by exchanging complete clutches between pairs of nests to increase or decrease the clutch size by zero (control), one, two or three eggs in 3l4 nests over 2 years. 3. Pre-fledging survival of goslings increased in enlarged broods and decreased in reduced broods compared to control. Consequently, enlarged broods fledged more offspring and the reverse was true for reduced broods. 4. Size and mass of goslings near fledging was also higher in enlarged broods than in control, which suggests that offspring quality was also enhanced by the manipulation. This is contrary to the common trade-off between offspring numbers and quality. 5. Large families were dominant over smaller ones in feeding sites, which could explain the increased survival and growth of enlarged broods. 6. Our results suggest that the ability to raise young does not limit clutch size in this species and that parents could be more successful (i.e. increase both the number and quality of their offspring) by laying more eggs. However, the time required to lay additional eggs reduces the viability of all offspring and may explain why females do not lay more eggs. (Au)

I
Animal growth; Animal health; Animal mortality; Animal population; Animal reproduction; Bird nesting; Greater Snow Geese

G0813
Bylot Island, Nunavut


Pingo growth and collapse, Tuktoyaktuk Peninsula area, Western Arctic coast, Canada : a long-term field study   /   Mackay, J.R.
(Géographie physique et quaternaire, v. 52, no 3, 1998, p. 271-323, ill., maps)
(PCSP/PPCP contribution, no. 012-97)
References.
ASTIS record 47483.
Languages: English
Web: doi:10.7202/004847ar
Libraries: ACU

Growth data from precise surveys have been obtained for 11 pingos for periods ranging from 20 to 26 years. Most of the 1350 pingos, perhaps one quarter of the world's total, have grown up in the bottoms of drained lakes underlain by sands. Permafrost aggradation on the drained lake bottoms has resulted in pore water expulsion, solute rejection below the freezing front, a freezing point depression, and groundwater flow at below 0°C to one or more residual ponds, the sites of pingo growth. Sub-pingo water lenses underlie many growing pingos. The pure ice which grows by downward freezing in a sub-pingo water lens may be composed of seasonal growth bands which, like tree rings, are of potential use in the study of past climates. Growing pingos underlain by sub-pingo water lenses can often be identified by features such as peripheral pingo rupture, spring flow, frost mound growth, normal faulting, and oscillations in pingo height. Such features, and others, are associated with hydrofracturing and water loss from a sub-pingo water lens. Some of the data derived from the long-term study of pingo growth are relevant to the identification of collapse features, interpreted as paleo-pingos, in areas now without permafrost. (Au)

C, B, E
Ground ice; Groundwater; Growth; Palaeoclimatology; Permafrost; Pingos

G0812
Tuktoyaktuk Peninsula, N.W.T.


Hybridization and the origin of the Arctic grass, Poa hartzii (Poaceae) : evidence from morphology and chloroplast DNA restriction site data   /   Gillespie, L.J.   Consaul, L.L.   Aiken, S.G.
(Canadian journal of botany, v. 75, no. 11, Nov. 1997, p.1978-1997, ill., 1 map)
(PCSP/PPCP contribution, no. 013-97)
References.
ASTIS record 52422.
Languages: English
Web: doi:10.1139/b97-910
Libraries: ACU

The hypothesized hybrid origin of Poa hartzii Gand. (Poaceae) was investigated by analysis of morphological and molecular data. This endemic nearctic caespitose grass has been considered to be a hybrid between two of the three sympatric arctic species, Poa glauca M. Vahl, Poa arctica R. Br., and Poa abbreviata R. Br. Field observations and morphological studies indicate that Poa hartzii is a morphologically distinct apomictic species that reproduces and disperses by seed. Restriction enzyme analysis of polymerase chain reaction amplified chloroplast DNA revealed the presence in Poa hartzii of two very different haplotypes. One haplotype is identical to the dominant type found in Poa glauca, while the second is identical to the haplotype of Poa secullda J. Presl., located south of the arctic region. These results are consistent with an hypothesis of ancient hybrid origin involving Poa glauca and Poa secunda, but not Poa arctica nor Poa abbreviata. They are also consistent with an hypothesis of cytoplasmic transfer via hybridization and introgression from Poa glauca to an ancestral Poa hartzii in the Poa secunda complex. Direction of transfer is suggested by the widespread occurrence of the Poa secunda haplotype in Poa hartzii and by closer morphological similarity with Poa secunda than Poa glauca. The origin of Poa hartzii provides an excellent example of reticulate evolution and the importance of hybridization in the speciation of arctic grasses. (Au)

H
Biomass; Evolution (Biology); Genetics; Grasses; Plant anatomy; Plant distribution; Plant taxonomy

G0813, G0812, G10
Axel Heiberg Island, Nunavut; Baffin Island, Nunavut; Canadian Arctic Islands; Cornwallis Island, Nunavut; Ellesmere Island, Nunavut; Greenland; Inuvialuit Settlement Region, N.W.T./Yukon; Mackenzie Delta, N.W.T.; Victoria Island, N.W.T./Nunavut


Graptolites of the genus Mediograptus Boucek and Pribyl from the uppermost Llandovery of Cornwallis Island, Arctic Canada   /   Loydell, D.K.   McKenniff, J.   Lenz, A.C.
(Canadian journal of earth sciences, v. 34, no. 6, June 1997, p. 765-769, ill.)
(PCSP/PPCP contribution, no. 016-97)
References.
ASTIS record 52425.
Languages: English
Web: doi:10.1139/e17-063
Libraries: ACU

Isolated specimens of three species of Mediograptus are described from latest Llandovery (Telychian) strata of the Cape Phillips Formation, Cornwallis Island. One species is new, Mediograptus? bicercis n.sp., whereas the other two, Mediograptus flittoni and Mediograptus morleyae, have previously been recorded only from the Telychian of Wales. A possible paleolatitudinal control on mediograptid distribution is suggested, with one suite of taxa charaterizing higher paleolatitudes (Bohemia), the other, including the species described herein, lower plaeolatitudes (Wales, Arctic Canada). The diagnosis for the genus Mediograptus is emended. (Au)

B, I
Animal distribution; Animal taxonomy; Graptolites; Palaeontology

G0813
Cornwallis Island, Nunavut; Phillips, Cape, Nunavut; Wales


Arctic and Antarctic lakes as optical indicators of global change   /   Vincent, W.F.   Laurion, I.   Pienitz, R.
(Papers from the International Symposium on Antarctica and Global Change : Interactions and Impacts, held at Hobart, Australia, 13-18 July 1997 / Edited by W.F. Budd. Annals of glaciology, v. 27, 1998, p. 691-696, ill.)
(PCSP/PPCP contribution, no. 018-97)
References.
ASTIS record 47193.
Languages: English
Libraries: ACU

Lakes are a major feature of Arctic and Antarctic landscapes and are likely to be sensitive indicators of climate change. New bio-optical technologies for in situ measurements (e.g. UV-profiling) and remote sensing (e.g. light detection and ranging) now offer a suite of options for long-term monitoring at these sites. Certain properties of high-latitude lakes are highly responsive to changes in climate forcing and could be targeted within a monitoring strategy based on optical properties; these include lake levels, lake-ice dynamics, phytoplankton biomass and chromophoric dissolved organic matter (CDOM). High-latitude lakes are optically sensitive to changes in CDOM export from their surrounding catchments that could result from climate effects on hydrology and vegetation. Using a new model based on biologically weighted transparency, we show that a 20% change in CDOM concentration (as measured by dissolved organic carbon) can have a much greater effect on UV inhibition of phytoplankton than a similar percentage change in stratopheric ozone. Much of this effect is due to UV-A, because the reduced photodamaging effect per unit energy (i.e. low biological weighting) in this waveband is offset by its higher incident flux at the lake surface relative to UV-B and its deeper penetration into the water column. These transparency calculations also show that small changes in CDOM in polar lakes will have a large effect on underwater light availability for photosynthesis. The spectral absorption and fluorescence properties of DCOM lend themselves to a variety of optical monitoring approaches. Future research on the paleo-optics of DCOM will allow the interpretation of current optical trends in high-latitude lakes relative to the scales of natural variability in the past. (Au)

E, F, H
Biomass; Climate change; Colored dissolved organic matter; Dissolved organic carbon; Effects monitoring; Hydrology; Lake ice; Lakes; Optical properties; Ozone; Phytoplankton; Remote sensing; Runoff; Solar radiation

G15, G081, G0826
Antarctic regions; Canadian Arctic; Eau Claire, Lac à l', region, Québec


Perennial spring occurrence in the Expedition Fiord area of western Axel Heiberg Island, Canadian High Arctic   /   Pollard, W.   Omelon, C.   Andersen, D.   McKay, C.
(Canadian journal of earth sciences, v. 36, no. 1, Jan. 1999, p. 105-120, ill., map)
(PCSP/PPCP contribution, no. 019-97)
References.
ASTIS record 47319.
Languages: English
Web: doi:10.1139/cjes-36-1-105
Libraries: ACU

This paper documents perennial spring activity at Expedition Fiord on western Axel Heiberg Island in the Canadian High Arctic. Two groups of mineralized springs occur near the McGill University Axel Heiberg Research Station located at 79°26'N, 90°46'W. The first is at Gypsum Hill, 3 km from the terminus of the White and Thompson glaciers, and the second site is at Colour Peak, approximately 10 km downvalley near the head of Expedition Fiord. Each spring group consists of 20-40 vents spread over several hundred square metres. The highly mineralized nature of the discharge causes a freezing-point depression of 7-10°C and produces a range of precipitates and travertine deposits. Year-round water temperature and discharge rate measurements have been obtained, demonstrating perennial activity at these sites. Results indicate that temperatures range from -4.0 to 6.6°C among the individual sources; however, water temperatures at the various outlets remain constant throughout the year despite a mean annual air temperature of -15°C. Although discharge from any one outlet is low (<0.5 to 2.0 L/s), the total discharge is substantial, each year producing several seasonal frost mounds and an icing 180 000-300 000 m² at the Gypsum Hill site. (Au)

F, C, B, G
Frost mounds; Geochemistry; Glaciology; Groundwater; Hydrology; Icings; Minerals; Permafrost; River discharges; Springs (Hydrology); Temperature

G0813
Colour Peak, Nunavut; Expedition Fiord region, Nunavut; Gypsum Hill, Nunavut


Geomorphic and hydrologic characteristics of perennial springs on Axel Heiberg Island, Canadian High Arctic   /   Pollard, W.H.   Omelon, C.   Andersen, D.   McKay, C.
(Permafrost : Seventh International Conference, June 23-27, 1998, Yellowknife, Canada : proceedings / Edited by Antoni G. Lewkowicz and Michel Allard. Collection Nordicana, no 57, 1998, p. 909-914, ill., maps)
(PCSP/PPCP contribution, no. 020-97)
References.
ASTIS record 44076.
Languages: English
Libraries: ACU

This paper documents the hydrologic and geomorphic characteristics of perennial springs on western Axel Heiberg Island in the Canadian High Arctic. Two groups of mineralized springs occur near the McGill Field Station at Expedition Fiord. The first group is 3 km from the terminus of the White and Thompson Glaciers discharging at the base of the east side of Gypsum Hill adjacent to the floodplain of the Expedition River. The second site is at Colour Peak near the head of Expedition Fiord, approximately 10 km down valley from Gypsum Hill. Each spring group consists of 20-40 outlets spread over several hundred square metres. The mineralized nature of the discharge is responsible for a range of precipitates and travertine deposits. This paper documents spring discharge, water chemistry, and mineral precipitates associated with the springs. (Au)

C, F, A
Geomorphology; Glaciers; Groundwater; Hydrology; Permafrost; Springs (Hydrology)

G0813
Colour Peak, Nunavut; Expedition Fiord region, Nunavut; Gypsum Hill, Nunavut


Massive ice formation in the Eureka Sound lowlands : a landscape model   /   Pollard, W.H.   Bell, T.
(Permafrost : Seventh International Conference, June 23-27, 1998, Yellowknife, Canada : proceedings / Edited by Antoni G. Lewkowicz and Michel Allard. Collection Nordicana, no 57, 1998, p. 903-908, ill., map)
(PCSP/PPCP contribution, no. 021-97)
References.
ASTIS record 44075.
Languages: English
Libraries: ACU

Massive ice is a common constituent in fine-grained marine sediments situated below the Holocene marine limit in the Eureka Sound area of Ellesmere and Axel Heiberg Islands. Its stratigraphic setting and character suggest it is intrasedimental in nature and formed as permafrost aggraded following Holocene emergence. This paper describes the relationship between ground ice occurrence and landscape evolution on Fosheim Peninsula, with particular emphasis on the duration and extent of glacier ice cover, sea level history, and the style and pattern of glaciomarine sedimentation in formerly submerged basins. A two-phase model is proposed to explain the nature of ground ice distribution. In this model permafrost conditions associated with late Quaternary glacial, periglacial and emergent environments are considered. The evolution of permafrost conditions is divided into two phases corresponding with: (a) prior to ~8-9 ka BP, and (b) post-glacial emergence after ~8 ka BP. (Au)

C, A, B
Bottom sediments; Glacial landforms; Permafrost; Quaternary period; Sedimentation; Sediments (Geology)

G0815
Eureka Sound, Nunavut


An assessment of ground ice volume near Eureka, Northwest Territories   /   Couture, N.J.   Pollard, W.H.
(Permafrost : Seventh International Conference, June 23-27, 1998, Yellowknife, Canada : proceedings / Edited by Antoni G. Lewkowicz and Michel Allard. Collection Nordicana, no 57, 1998, p. 195-200, ill., map)
(PCSP/PPCP contribution, no. 022-97)
References.
ASTIS record 44066.
Languages: English
Libraries: ACU

In the area surrounding Eureka, Northwest Territories, ground ice accounts for a significant fraction of surficial material, comprising 30.8% of the upper 5.9 m of permafrost. Volume depends on the type of ice examined, ranging from 1.8 to 69.0% in different regions of the study area. Excess ice accounts for 1.3% of frozen materials. In areas underlain by massive ice, 16.2% of the permafrost is considered to be excess ice. Data is drawn from ground measurements and a number of secondary sources, including air photographs, maps, and previous studies which examined specific occurrences of ground ice in the Eureka area. The importance of quantifying the volume of ground ice in this area is discussed, especially in light of how a warming climate and anthropogenic activities in the area can alter the landscape. (Au)

C, A, E, B
Climate change; Environmental impacts; Ground ice; Permafrost; Sediments (Geology); Thawing; Thermokarst

G0813
Eureka region, Nunavut


Massive ground ice within Eureka Sound bedrock, Ellesmere Island, Canada   /   Robinson, S.D.   Pollard, W.H.
(Permafrost : Seventh International Conference, June 23-27, 1998, Yellowknife, Canada : proceedings / Edited by Antoni G. Lewkowicz and Michel Allard. Collection Nordicana, no 57, 1998, p. 949-954, ill., maps)
(PCSP/PPCP contribution, no. 023-97)
References.
ASTIS record 44078.
Languages: English
Libraries: ACU

This paper presents observations from a natural exposure on the bank of Hot Weather Creek, Ellesmere Island, showing three distinct massive ice types: 1) discrete ice sills within poorly consolidated bedrock, 2) segregated massive ice, and 3) a large ice wedge within overlying unconsolidated fluvial sediments. Stratigraphic observations and hydrochemistry data indicate that the three ice types have different modes of origin and water sources. Ice wedge formation followed marine regression, which exposed unfrozen sediments to cold air and promoted the aggradation of permafrost. The formation of segregated ice was promoted by the downward progression of permafrost, an ample water source and the presence of a fine-grained capping layer. The downward aggradation of permafrost combined with the presence of a lower confining boundary likely resulted in the highly pressurized groundwater required to form ice sills in the already frozen bedrock. (Au)

C, F, B
Ground ice; Groundwater; Hydrology; Permafrost; Stratigraphy

G0813
Hot Weather Creek, Nunavut


Seasonal variation in growth of Greater Snow Goose goslings : the role of food supply   /   Lepage, D.   Gauthier, G.   Reed, A.
(Oecologia, v.114, no. 2, Apr. 1998, p. 226-235, ill.)
(PCSP/PPCP contribution, no. 025-97)
References.
ASTIS record 47628.
Languages: English
Web: doi:10.1007/s004420050440
Libraries: ACU

Even though growth rate is an important fitness component, it is still controversial to what extent parent birds adjust the timing of offspring hatch to natural variations in food supply to maximize offspring growth. We studied the role of food availability in explaining inter- and intra-seasonal variation of growth rate in goslings of greater snow geese over 5 years. The peak of hatching generally coincided with the peak of food availability. However, early-hatched goslings usually grew faster than birds hatched at the peak, which in turn grew faster than late-hatched goslings, although this phenomenon was not observed in all years. There was considerable variation in growth rate among the five years, the smallest goslings produced in the best year (1991) being larger than the largest goslings of the poorest year (1994). We developed three indices of food availability, based on the cumulative availability of plant biomass and nitrogen content during the growth period, and showed that the cumulative exposure to nitrogen biomass explained up to 43% of variation (intra- and inter-annual) in body size just before fledging. In years with good feeding conditions, early-hatched goslings had access to more nitrogen during their growing period than those hatching on or after the peak and they grew faster. In years of lower food availability, early-hatched goslings had no detectable advantage over peak- or late-hatched birds for access to protein-rich food and no seasonal decline in growth rate was observed. These results confirm the critical role of food supply in the seasonal variation of growth rate in Arctic-nesting geese. (Au)

I, H, F, A
Animal behaviour; Animal food; Animal growth; Animal migration; Animal reproduction; Animal tagging; Biological clocks; Biomass; Bird nesting; Eriophorum; Grasses; Greater Snow Geese; Nitrogen; Nitrogen cycling; Primary production (Biology); Tundra ponds; Wetlands

G0813
Bylot Island, Nunavut


Birds of Bylot Island and adjacent Baffin Island, Northwest Territories, Canada, 1979 to 1997   /   Lepage, D.   Nettleship, D.N.   Reed, A.
(Arctic, v. 51, no. 2, June 1998, p. 125-141, maps)
(PCSP/PPCP contribution, no. 026-97)
References.
ASTIS record 43032.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic51-2-125.pdf
Web: doi:10.14430/arctic1054
Libraries: ACU

Observations of birds in the Bylot Island region from 1979 to 1997, with emphasis on the southwest part of the island each summer since 1989, revealed an avifauna composed of 63 species, of which 35 were breeding. Thirteen species are new records for the region, including one for the Northwest Territories (black-headed gull, Larus ridibundus) and two for the Canadian Arctic Archipelago (killdeer, Charadrius vociferus; mew gull, Larus canus). Two species, Canada goose (Brant canadensis) and red knot (Calidris canutus), were also confirmed as breeders for the first time in the region. A summary of these avifaunal observations, along with a review of previous observations made in the region, allows changes in population size and status of individual species to be identified. These records combined with those from earlier studies give a total of 74 species for the Bylot Island region, 45 confirmed as breeders. This makes the avian community in the area one of the most diverse known north of 70° N latitude in the Canadian Arctic Archipelago. (Au)

I, E, D, G
Animal distribution; Animal population; Bird nesting; Birds; Canada Geese; Gulls; Killdeers; Meteorology; Polynyas; Red Knots

G0813
Baffin Island, Nunavut; Bylot Island, Nunavut


U-Pb geochronology of the eastern Hall Peninsula, southern Baffin Island, Canada : a northern link between the Archean of West Greenland and the Paleoproterozoic Torngat Orogen of northern Labrador   /   Scott, D.J.
(Precambrian research, v. 93, no. 1, Jan. 1999, p. 5-26, ill., 1 map)
(PCSP/PPCP contribution, no. 027-97)
References.
ASTIS record 45089.
Languages: English
Web: doi:10.1016/S0301-9268(98)00095-3
Libraries: ACU

A corridor east of Iqaluit that crosses several regionally significant lithologic boundaries has been mapped and sampled for geochronology. Zircon, monazite and titanite were analysed by the isotope dilution U-Pb method to characterize igneous and metamorphic events, and Pb-Pb ages of detrital zircons were determined by laser ablation microprobe ICP-MS. Tonalitic gneisses at the eastern end of the corridor are Archean, with emplacement ages of 2920+8/-6, 2848±3, 2844+6/-5 and 2797+27/-15 Ma; these samples record variable tectonothermal overprints at ca 2.77 Ga, and between 1844 and 1736 Ma, and may be related to similar rocks in West Greenland. A sequence of quartzites and semipelites associated with the Archean gneisses contains exclusively Archean detrital zircons, and was metamorphosed at 1.88 Ga. In the central part of the corridor, semipelitic and psammitic rocks contain almost exclusively Paleoproterozoic detritus deposited after 1.93 ±0.05 Ga, and are interpreted as the northern continuation of the Tasiuyak gneiss of the Torngat Orogen. At the western end of the corridor, monzogranites of the Cumberland batholith intruded at 1869+9/-3, 1857+5/-3 and 1850+3/-2 Ma. The present data suggest that the north-south Nagssugtoqidian collision (<1.89 Ga) in West Greenland may predate the east-west Torngat collision (<1.87 Ga) in northern Labrador. (Au)

B
Archaean era; Batholiths; Deformation; Geological time; Geology; Gneiss; Isotopes; Lead; Minerals; Radioactive dating; Rocks; Uranium; Zircon

G0813, G10, G0827
Baffin Island, Nunavut; Brevoort Island (63 30 N, 64 20 W), Nunavut; Hall Peninsula, Nunavut; Nunatsiavut, Labrador; Vestgrønland


Seasonal and spatial variations in the chemistry of a High Arctic supraglacial snow cover   /   Sharp, M.   Skidmore, M.   Nienow, P.
(Journal of glaciology, v. 48, no.160, 2002, p. 149-158, ill., maps)
(PCSP/PPCP contribution, no. 029-97)
References.
ASTIS record 51950.
Languages: English
Web: doi:10.3189/172756502781831683
Libraries: ACU

This paper describes the physical and chemical properties of the snowpack on John Evans Glacier, Ellesmere Island, Canadian Arctic Archipelago, and investigates the controls on snowpack solute concentrations and atmospheric deposition. The snowpack contains three layers that are traceable across the whole glacier. These represent fall accumulation that has been metamorphosed to depth hoar, winter accumulation mixed with snow reworked by wind from the underlying depth hoar, and spring accumulation mixed with wind-reworked snow. The seasonal cycle in snow chemistry closely reflects changes in the composition of the atmospheric aerosol at Alert, with some modification of NO3- concentrations by post-depositional processes. Mean water-weighted solute concentrations in the snowpack are largely independent of accumulation, while atmospheric deposition tends to increase with accumulation. This suggests that, for most species, wet deposition is the dominant depositional process throughout the year. However, concentrations of Ca++ and K+ increase with both accumulation and elevation, implying an enhanced input from dry deposition of soil dust above 800 m elevation. Concentrations of SO4-- are inversely related to accumulation, especially in the winter layer, suggesting a significant input from non-precipitating events, such as dry deposition or riming, during this period of very limited snowfall. (Au)

F, E, J
Accumulation; Aerosols; Air pollution; Atmospheric chemistry; Atmospheric circulation; Chemical properties; Cores; Electrical properties; Glaciers; Measurement; Physical properties; Seasonal variations; Snow; Snow stratigraphy; Snow water equivalent; Spatial distribution; Temperature; Weather stations

G0813
Alert, Nunavut; John Evans Glacier, Nunavut


Periglacial features developed on the exposed lake bottoms of seven lakes that drained rapidly after 1950, Tuktoyaktuk Peninsula area, Western Arctic coast, Canada   /   Mackay, J.R.
(Permafrost and periglacial processes, v. 10, no. 1, Jan.-Mar. 1999, p. 39-63, ill.)
(PCSP/PPCP contribution, no. 001-98)
References.
ASTIS record 47556.
Languages: English
Web: doi:10.1002/(SICI)1099-1530(199901/03)10:1<39::AID-PPP305>3.3.CO;2-I
Libraries: ACU

A variety of periglacial features have been studied on the exposed bottoms of seven lakes that drained rapidly after 1950 in the Tuktoyaktuk Peninsula area, western Arctic coast, Canada. Ice- wedge growth commenced as early as the first winter following drainage. In most areas, ice-wedge growth ceased within several decades, because of the growth and spread of vegetation which resulted in snow entrapment and increased ground temperatures. At sites where thermokarst lake enlargement had transgressed across terrain with ice-wedge polygons, reactivated polygon patterns developed rapidly in some pre-drainage shallow water areas, with the sites of former troughs becoming ridges. Excavations across the ridges exposed extensive differential frost heave, cryoturbations, and slickensided vertical shear planes. Many collapse pits developed because of differential frost heave between silts and sands, cavity formation beneath the frozen silts, and cavity infilling with adjacent sand in late summer. Other collapse pits developed, either subaqueous1y prior to drainage or subaerially after drainage. Underground flow has been observed, in early summer, where a near-surface layer of ice-rich silts was underlain by desiccated active layer sands at a temperature well below 0°C. At some sites where there has been underground flow some differential loading and water escape features appear to have developed during the thaw period. (Au)

A, C, F, H, E, J
Active layer; Climatology; Drainage; Frost heaving; Frozen ground; Groundwater; Ice wedges; Lakes; Moisture transfer; Patterned ground; Periglacial landforms; Plant succession; Precipitation (Meteorology); Sand; Silt; Soil temperature; Thawing; Thermokarst; Tundra ecology

G0812
Richards Island, N.W.T.; Tuktoyaktuk Peninsula, N.W.T.


Holocene delevelling of Devon Island, Arctic Canada : implications for ice sheet geometry and crustal response   /   Dyke, A.S.
(Canadian journal of earth sciences, v. 35, no. 8, Aug. 1998, p. 885-904, ill., maps)
(PCSP/PPCP contribution, no. 002-98)
Appendix.
References.
ASTIS record 47315.
Languages: English
Web: doi:10.1139/e98-034
Libraries: ACU

The raised beaches and deltas of Devon Island contain an abundance of dateable materials. A large set of radiocarbon dates (228), 154 of which are new, are used to construct relative sea level curves and isobase maps for the island. The best materials for this purpose are driftwood logs (61 dates) and bowhead whale bones (74 dates) from raised beaches and mollusc shells from marine-limit deltas (20 dates) or from altitudes close to marine limit (14 dates). During the last glacial maximum, the island is thought to have lain beneath the southeastern flank of the Innuitian ice sheet. The relative sea level history is congruent with that inferred ice configuration. The island spans half the ice sheet width. Relative sea level curves are of simple exponential form, except near the glacial limit where an early Holocene emergence proceeded to a middle Holocene lowstand below present sea level, which was followed by submergence attending the passage of the crustal forebulge. The response times of relative sea level curves and of crustal uplift decrease from the uplift centre toward the limit of loading, but the change appears strongest near the limit. The Innuitian uplift is separated from the Laurentide uplift to the south by a strong isobase embayment over Lancaster Sound. Hence, ice load irregularities with wavelengths of about 100 km were large enough to leave an isostatic thumbprint in this region of the continent. The apparent absence of a similar embayment over Jones Sound probably indicates a greater Late Wisconsinan ice load there, or a thicker crust than in Lancaster Sound. (Au)

A, B
Beach erosion; Beaches; Bones; Bowhead whales; Driftwood; Glacial epoch; Glaciation; Ice sheets; Islands; Palaeogeography; Radiocarbon dating; Recent epoch; River deltas; Sea level; Shorelines

G0813
Devon Island, Nunavut


The Late Wisconsinan and Holocene record of walrus (Odobenus rosmarus) from North America : a review with new data from Arctic and Atlantic Canada   /   Dyke, A.S.   Hooper, J.   Harington, C.R.   Savelle, J.M.
(Arctic, v. 52, no. 2, June 1999, p. 160-181, ill., maps)
(PCSP/PPCP contribution, no. 003-98)
References.
ASTIS record 44934.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic52-2-160.pdf
Web: doi:10.14430/arctic920
Libraries: ACU

The Late Wisconsinan and Holocene record of the Atlantic walrus is known from numerous collections of bones and tusks from Arctic Canada and south to North Carolina, as well as from many archaeological sites in the Arctic and Subarctic. In contrast, the Pacific walrus has no dated Late Wisconsinan or early Holocene record in North America, and it may have been displaced into the northwest Pacific at Last Glacial Maximum (LGM). The Atlantic walrus rapidly exploited newly deglaciated territory, moving northward from its LGM refugium and reaching the Bay of Fundy by 12 800 B.P., the Grand Banks by 12 500 B.P., southern Labrador by 11 500 B.P., and the central Canadian Arctic Archipelago (CAA) by 9700 B.P. Its southern range limit my have retracted to the Bay of Fundy by ca. 7500 B.P. Within the CAA, walrus remains clustered in two main age groups: 9700 to 8500 B.P. and 5000 to 4/3000 B.P. This pattern strongly resembles the distribution of bowhead whale radiocarbon ages from the same area, which suggests a common control by sea-ice conditions. Walrus remains occur in Indian culture archaeological sites as old as 7500 B.P. and, in some cases (Namu, British Columbia, and Mackinac Island, Michigan), they evidently represent long-distance human transport. They are much more common in Paleoeskimo and Neoeskimo culture sites. However, they occur in very low abundances, and generally as debitage, in sites older than Dorset (2500 B.P.). The walrus, therefore, may not have been hunted by early Paleoeskimos. Beginning with Early Dorset, walrus remains occur in definite diet-related contexts. Middle Dorset (2300 to 1500 B.P. and late Thule (<400 B.P.) sites are missing from the High Arctic, and there may be a similar gap in the middle Pre-Dorset (3400 to 2600 B.P.). Sea-ice conditions at these times may have adversely affected availability of walrus and other marine mammal resources. Walrus is a prominent faunal element in Middle Dorset sites on the Labrador coast; this is consistent with a southward displacement of people and resources. (Au)

B, A, I, U, J, E
Age; Animal distribution; Bones; Climate change; Evolution (Biology); Glacial epoch; Inuit archaeology; Middens (Archaeology); Palaeoclimatology; Palaeoecology; Palaeontology; Pleistocene epoch; Radiocarbon dating; Recent epoch; Sea ice; Walruses

G081, G06, G10, G0827
Labrador; North American Arctic; North Atlantic Ocean


Field investigations of permafrost and climatic change in northwest North America   /   Burn, C.R.
(Permafrost : Seventh International Conference, June 23-27, 1998, Yellowknife, Canada : proceedings / Edited by Antoni G. Lewkowicz and Michel Allard. Collection Nordicana, no 57, 1998, p. 107-120, ill., 1 map)
(PCSP/PPCP contribution, no. 004-98)
References.
ASTIS record 45339.
Languages: English
Libraries: ACU

Yukon Territory, adjacent portions of Northwest Territories, and Alaska contain a continental range of permafrost conditions. The response of permafrost to climatic change is recorded in the cryostratigraphy of late Pleistocene and Holocene sediments, with an early Holocene thaw unconformity being a widespread and prominent feature. More recently, temperature profiles from deep boreholes show an inflection associated with near-surface warming of 2 to 4 C since the Little Ice Age. Simultaneously, the southern limit of permafrost has moved northwards. In order to understand the present climate:ground temperature system, an analytical solution has been verified to relate the annual mean ground surface temperature to the annual mean permafrost surface temperature under equilibrium conditions. Ground surface temperatures have been obtained from air temperatures using n-factors. The solution assumes that heat transfer in the active layer is only by conduction. The relations show that the impact on permafrost temperatures per se. Observations from the sporadic permafrost zone indicate the persistence of permafrost despite recent warming. This is due to minimal snow cover on residual peat landforms, and to latent heat in ice-rich ground. The persistence further complicates interpretation of the response of permafrost to climate change. (Au)

C, E, B
Active layer; Atmospheric temperature; Climate change; Frozen ground; Ground ice; Heat transmission; Ice wedges; Mathematical models; Measurement; Palaeoclimatology; Permafrost; Spatial distribution; Temperature

G0812, G0811, G06
Alaska; N.W.T.; Richards Island, N.W.T.; Yukon


Electrical potentials measured during growth of lake ice, Mackenzie Delta area, N.W.T., Canada   /   Burn, C.R.   Parameswaran, V.R.   Kutny, L.   Boyle, L.
(Permafrost : Seventh International Conference, June 23-27, 1998, Yellowknife, Canada : proceedings / Edited by Antoni G. Lewkowicz and Michel Allard. Collection Nordicana, no 57, 1998, p. 107-120, ill., 1 map)
(PCSP/PPCP contribution, no. 005-98)
References.
ASTIS record 45338.
Languages: English
Libraries: ACU

Electrical potentials generated during freezing were measured weekly between November 1996 and March 1997 in two lakes near Inuvik, N.W.T. One is an upland setting, and receives only local water. The other, in the Mackenzie Delta, is connected to the Mackenzie River's discharge throughout the year. The potentials were measured in the uppermost metre of each lake on electrodes mounted on a PVC pipe and spaced at 10 cm intervals. The potentials were measured with reference to a basal electrode, which remained in water below the ice through the winter. The temperature at each electrode was measured by thermistors, to determine the development of the ice cover. Potential differences of up to 700 mV were recorded between the lower water pool and the ice throughout the winter at both lakes. The ice was of negative polarity in each case. (Au)

G, F
Chemical properties; Electrical properties; Instruments; Lake ice; Lakes; Measurement; Temperature; Thawing

G0812
Inuvik region, N.W.T.; Mackenzie Delta, N.W.T.


Daily departure and return patterns of wolves, Canis lupus, from a den at 80°N latitude   /   Mech, L.D.   Merrill, S.B.
(Canadian field-naturalist, v.112, no. 3, July-Sept. 1998, p. 515-517, ill.)
(PCSP/PPCP contribution, no. 006-98)
References.
ASTIS record 47222.
Languages: English
Libraries: ACU

We report on daily patterns of Wolf (Canis lupus) departures from, and returns to, their den on Ellesmere Island, Northwest Territories, Canada (80°N) during summers between 1988 and 1996. Based on 1759 h of observation, the Wolves departed more often than random during 2200 to 0400 h. There was no darkness during summer, so any sun-based temporal cues must have come from sun position. (Au)

I
Animal behaviour; Animal food; Biological clocks; Denning; Light; Predation; Wolves

G0813
Ellesmere Island, Nunavut


Upper and lower plate juxtaposition, deformation and metamorphism during crustal convergence, Trans-Hudson Orogen (Quebec-Baffin segment), Canada   /   St-Onge, M.R.   Lucas, S.B.   Scott, D.J.   Wodicka, N.
(Precambrian research, v. 93, no. 1, Jan. 1999, p. 27-49, ill., 1 map)
(PCSP/PPCP contribution, no. 009-98)
References.
ASTIS record 45090.
Languages: English
Web: doi:10.1016/S0301-9268(98)00096-5
Libraries: ACU

The lower plate of the Quebec-Baffin segment of Paleoproterozoic Trans-Hudson Orogen comprises parautochthonous Archean crystalline basement of the Superior Province (3.22-2.74 Ga) and imbricated Paleoproterozoic rift-margin strata (2.04-1.92 Ga). The collisional upper plate contains (1) allochthonous ophiolitic units (2.00 Ga), (2) a continental arc terrane (Narsajuaq arc; 1.86-1.82Ga), (3) shelf sequence strata (ca. <1.93 Ga and >1.86Ga) and basement orthogneisses (ca. 1.95 Ga), (4) foreland basin deposits (<1.93 Ga and >1.86 Ga), and (5) a batholith which intrudes the shelf and foreland basin rocks (Cumberland batholith; 1.86-1.85 Ga). Lower and upper plate assemblages were juxtaposed during a 1.82-1.79 Ga accretion-collision event, and deformed into regional-scale folds during two post-collisional folding episodes (ca. 1.76-1.74 Ga). As a result of the structural relief generated by the post-collisional folding and subsequent exhumation, all orogenic elements can be directly examined along a 400 km, across-strike transect. In the external zone (northern Quebec), lower plate rift-margin units were internally imbricated (Cape Smith Belt) and translated southward across the Superior Province basement. Paleoproterozoic amphibolite facies mineral growth is syn to post-thrusting. Tectonic imbrication has resulted in a structural inversion of the accreted (i.e. upper plate) ophiolite stratigraphy. North of the Cape Smith Belt, mid-crustal plutonic units of the Narsajuaq arc form an upper plate crystalline wedge whose sole thrust is localized near the thrust belt's basal decollement. Within Narsajuaq arc, syn-magmatic granulite facies assemblages are retrogressed to amphibolite facies assemblages in proximity to major accretion-collision faults. In the internal zone (southern Baffin Island), a tripartite orogen-scale tectonostratigraphy is exposed on the flanks of the post-collisional fold structures. At the lowest structural level, lower plate Superior Province orthogneisses are imbricated with Paleoproterozoic rift-margin units, and mineral growth is syn-thrusting. At intermediate structural level, upper plate orthogneisses are correlated with the Narsajuaq arc in northern Quebec. At the highest structural level, a north-facing shelf sequence is structurally overlain by an assemblage of clastic rocks interpreted as a foreland basin sequence. Dominantly-monzogranite plutons of the Cumberland batholith are restricted to the upper structural level and indicate pre-emplacement imbrication of tectonostratigraphic units. Within both upper and lower plates, granulite facies assemblages are retrogressed to upper amphibolite assemblages in proximity to 1.82-1.79 Ga accretion-collision structures. Exposures of Superior Province basement across the orogen document a progressive increase in the extent of reworking during accretion of upper plate units, from a narrow shear zone in the external zone to km-scale imbrication and more pervasive shear deformation in the internal zone. A minimum of 160 km of basement underthrusting is constrained by the structural overlap of upper plate allochthons on lower plate units. Basement involvement during post-collision shortening is manifest as thick-skinned folding, indicating coupling across the collisional basal decollement. (Au)

B
Archaean era; Batholiths; Deformation; Folds (Geology); Geological time; Metamorphism (Geology); Radioactive dating; Rocks; Stratigraphy; Structural geology; Zircon

G0813, G0826
Baffin Island, Nunavut; Ungava, Péninsule d', Québec


Breeding, moulting, and site fidelity of brant (Branta bernicla) on Bathurst and Seymour Islands in the Canadian High Arctic   /   O'Briain, M.   Reed, A.   Macdonald, S.D.
(Arctic, v. 51, no. 4, Dec. 1998, p. 350-360, ill., 1 map)
(PCSP/PPCP contribution, no. 011-98)
References.
ASTIS record 43894.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic51-4-350.pdf
Web: doi:10.14430/arctic1078
Libraries: ACU

We studied the breeding and moulting ecology of eastern High Arctic brant, Branta bernicla hrota on Bathurst and Seymour Islands in the central Canadian High Arctic from 1968 to 1989. In most years, brant arrived in Polar Bear Pass, Bathurst Islnd, during the first few days of June (earliest 28 May 1977), where they fed for several days in small flocks before dispersing to nesting areas. First eggs were usually laid on 13 June and the peak of nest initiation occurred about 16 June. The mean clutch size was 4.5 eggs, and the mean incubation period 23 days. Broods were raised along the shorelines of lakes, ponds, estuaries, and rivers. Goslings were capable of flight by 42-43 days. During the 10 years when the studies were most intensive (1974-77 and 1984-89), there were three years in which brant did not attempt to nest (1974, 1986, 1988); they nested in all other years and were known to produce fledged young in at least four of them. Nesting was not attempted when the mean temperature for the period 1-20 June was below -3 C. On Bathurst Island in 1987, arctic foxes (Alopex lagopus) preyed heavily on brant eggs, and no young were fledged. Nonbreeding adults assembled in small flocks to moult around nerby inland lakes, in river valleys, and at the mouths of estuaries, and concentrated in the latter in cold summers when inland sites had heavier ice cover. The flightless period began about 6 July and lasted 20-22 days. The recapture or resighting of brant marked on Bathurst Island showed that many adults returned in subsequent years to the same breeding territories, and in nonbreeding years they moulted nearby. A smaller proportion of the brant that had been marked as goslings and yearlings also returned to the island. In comparison with most other stocks of North American brant, those we studied bred at high latitude. That choice of breeding site subjected them to periodic breeding failures caused by cold springs and to a reduced availability of plant biomass, but it offered the advantage of reduced spring snow depth and a full 24 h of daylight for feeding during nesting and brood rearing. By using small wetlands which thaw early in close proximity to nesting sites, these brant were able to initiate egg laying relatively early and produce large clutches in most years. The low availability of plant biomass in the High Arctic probably explained the wide dispersal and low densities of these brant during breeding and moulting. (Au)

I, J, H
Animal behaviour; Animal distribution; Animal food; Animal growth; Animal migration; Animal mortality; Arctic foxes; Biomass; Bird nesting; Plumage; Predation; Primary production (Biology); Tundra ecology; Wetlands

G0813
Bathurst Island, Nunavut; Seymour Island, Nunavut


Evaluating nutritional condition of grizzly bears via select blood parameters   /   Gau, R.J.   Case, R.
(The Journal of wildlife management, v. 63, no. 1, Jan. 1999, p. 286-291)
(PCSP/PPCP contribution, no. 012-98)
References.
Four publications have PCSP/PPCP contribution number 012-98. The other ones are ASTIS records 50671, 51860 and one that has not yet been added to ASTIS.
ASTIS record 47580.
Languages: English
Web: doi:10.2307/3802511
Libraries: ACU

The use of blood parameters to estimate nutritional condition of bears has yet to be validated with actual body compositions. We used bioelectrical impedance analysis (BIA) to accurately estimate the body composition of a free-ranging population of grizzly bears (Ursus arctos) from the central Arctic of the Northwest Territories (NWT), Canada. We then correlated their blood hematology and metabolite parameters, previously identified by other studies on black bears (U. americanus) and grizzly bears to be useful indicators of nutritional condition, to the percentage of total body fat determined by BIA. None of the examined blood parameters had a significant relation with total body fat levels that were free from the effects of activity, stress, or dietary changes. Thus, interpretations of a grizzly bear's nutritional condition via the blood parameters we examined would be spurious. (Au)

I
Animal food; Animal health; Animal live-capture; Animal physiology; Animal tagging; Biological sampling; Blood; Fats; Grizzly bears

G0812
Daring Lake region, N.W.T.


Feeding patterns of barren-ground grizzly bears in the central Canadian Arctic   /   Gau, R.J.   Case, R.   Penner, D.F.   McLoughlin, P.D.
(Arctic, v. 55, no. 4, Dec. 2002, p. 339-344, maps)
(PCSP/PPCP contribution, no. 012-98)
References.
Four publications have PCSP/PPCP contribution number 012-98. The other ones are ASTIS records 47580, 51860 and one that has not yet been added to ASTIS.
ASTIS record 50671.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic55-4-339.pdf
Web: doi:10.14430/arctic717
Libraries: ACU

We collected 169 grizzly bear scats between 1994 and 1997 to determine the dietary habits of barren-ground grizzly bears (Ursus arctos) inhabiting Canada's central Arctic. From personal observations and fecal analysis, we concluded that barren-ground grizzly bears lead a predominantly carnivorous lifestyle and are effective predators of caribou (Rangifer tarandus). Caribou was a predominant diet item during spring, mid-summer, and fall. During early summer, grizzly bears foraged primarily on green vegetation. Berries increased in dietary importance in late summer. Declines in the caribou population of our study area or long-term absences of caribou may threaten the local grizzly bear population. (Au)

I, H, J, P
Animal behaviour; Animal distribution; Animal food; Animal health; Animal migration; Animal population; Animal waste products; Berries; Caribou; Diamonds; Effects monitoring; Environmental impacts; Grizzly bears; Mining; Plants (Biology); Predation; Radio tracking of animals; Research

G0812, G0813
Contwoyto Lake region, N.W.T./Nunavut; Gras, Lac de, region, N.W.T.; MacKay Lake region, N.W.T.


Hierarchical habitat selection by barren-ground grizzly bears in the central Canadian Arctic   /   McLoughlin, P.D.   Case, R.L.   Gau, R.J.   Cluff, H.D.   Mulders, R.   Messier, F.
(Oecologia, v.132, no. 1, June 2002, p. 102-108, ill., 1 map)
(PCSP/PPCP contribution, no. 012-98)
References.
Four publications have PCSP/PPCP contribution number 012-98. The other ones are ASTIS records 47580, 50671 and one that has not yet been added to ASTIS.
ASTIS record 51860.
Languages: English
Web: doi:10.1007/s00442-002-0941-5
Libraries: ACU

Using resource selection functions, we examined habitat selection patterns of barren-ground grizzly bears (Ursus arctos) in the central Canadian Arctic among and within home ranges. There was no difference between the sexes with regard to habitat selection patterns at the home range level (Wilks' lambda, approx. F11,11=1.27, P=0.37). Bear home ranges contain more esker habitat, tussock/hummock successional tundra, lichen veneer, birch seep, and tall shrub riparian areas relative to the proportional availability of habitats in the study area. We observed differences in habitat selection within home ranges among levels of sex/reproductive status (Wilks' lambda, approx. F20,412=3.32, P<0.001) and by season (Wilks' lambda, approx. F30,605=2.71, P<0.001). Eskers and tall shrub riparian zones were the habitats most preferred by bears throughout the year. Tussock/hummock successional tundra was also favored by males at varying times during the year and lichen veneers were favored in spring and autumn by most bears. Females with cubs tended to avoid the highest ranked habitat for males throughout the year. This pattern of habitat selection was not observed for females without accompanying young. Results of this study underline the importance of scale dependence in habitat selection. Failure to view habitat selection as a hierarchical process may result in a narrow and possibly misleading notion of habitat selection patterns. (Au)

I, J, H, A
Animal behaviour; Animal distribution; Animal food; Eskers; Gender differences; Grizzly bears; Hummocks; Lichens; Plant distribution; Radio tracking of animals; Seasonal variations; Wildlife habitat

G0812, G0813
Contwoyto Lake region, N.W.T./Nunavut; Gras, Lac de, region, N.W.T.


Kitigaaryuit Oral Traditions Research Project 1996 : English translations and transcripts of interview tapes #1-17   /   Cockney, C.   Inuvialuit Social Development Program [Sponsor]
Inuvik, N.W.T. : Inuvialuit Social Development Program, 1997.
247 p. ; 28 cm.
(PCSP/PPCP contribution, no. 014-98)
Cover title: Kitigaaryuit Oral Traditions Research Project - 1996 : interview transcripts.
Date (1997) handwritten on title page.
No PCSP/PPCP contribution number is given in this publication, but ASTIS is reasonably certain that 014-98 is the correct number.
Partial contents: Tapes 1A, 2A & 2B Laura Raymond and Sarah Mangelana; Tape 3A Laura Raymond, Sarah Mangelana and Norman Felix; Tapes 3B & 4A Laura Raymond and Sarah Mangelana; Tapes 4B, 5A, 5B & 6A Laura Raymond, Sarah Mangelana, Norman Felix and Edgar Kotokak; Tape 6B Sarah Mangelana, Norman Felix and Edgar Kotokak; Tapes 7A & 7B Jimmy Gordon; Tape 8A Laura Raymond, Sarah Mangelana, Norman Felix and Edgar Kotokak; Tapes 8B & 9A Laura Raymond, Sarah Mangelana and Norman Felix; Tapes 10A & 10B Laura Raymond; Tapes 11A, 11B, 12A, 12B, 13A, 13B & 14A Frank Cockney; Tapes 15A, 15B, 16A, 16B & 17A Willie Gruben.
ASTIS record 74037 describes the archaeology component of this project.
ASTIS record 74038.
Languages: English

... In 1994, the Inuvialuit Social Development Program (ISDP) learned that one of the largest traditional gathering places of the Inuvialuit, Kitigaaryuit, was declared a National Historic Site by the Historic Sites and Monuments Board of Canada in 1978. Since no work was initiated since its declaration, in 1995 the ISDP took the initiative to identifying ways to commemorate the site which is significant not only in the history of the Inuvialuit but to the prehistory of Canada. Although there is historical information available on Kitigaaryuit, the information is mainly on the archaeological work done previously on the island and in historical data of the Hudson's Bay Archives. What is lacking in the resources available is the history of the people who once inhabited the area in great numbers, the Inuvialuit. Some information on Kitigaaryuit were collected from elders in the 1970s during the Committee of Original People's Entitlement (COPE) Oral History Project but the contents of many of these tapes are unknown as many have not been fully transcribed. Other information such as identifying the boundaries of Kitigaaryuit, a full description and inventory of identifiable cultural/archaeological features and descriptions of past and present features are also required in order to get a good understanding of the importance of this site in Inuvialuit and more recent history. With these identifiable needs, ISDP approached Canadian Heritage/Parks Canada to initiate a project to collect the oral history/traditional knowledge of the Inuvialuit, to conduct an archaeological inventory and mapping of the site and to gather as much historical information available on Kitigaaryuit. The information gathered will form the groundwork for further research in seeking ways to commemorate Kitigaaryuit as a National Historic Site. There are various spellings of Kitigaaryuit. In the official maps produced by the Department of Energy, Mines and Resources, Ottawa, Kitigaaryuit is spelt as Kittigazuit which is the most recognized spelling of this location. In Inuvialuit Pitqusiit, Kitigaaryuit is spelt as Kitigaryuit which was adopted by the researchers of the publication. For this project, it was decided that Kitigaaryuit will he used as this was the way it was spelt by the late Raymond Mangelana who was very knowledgeable and literate in the Siglitun dialect of the Inuvialuktun language. Beverly Amos, who is a translator and transcriber of the Siglit language, verified the spelling as Kitigaaryuit by the way it is pronounced by elders and the late Felix Nuyaviak in his tape recordings. ... The first major task of the Kitigaaryuit Oral Traditions Research Project was to identify and interview elders in the Inuvialuit Settlement Region who may have stories/memories of past life at Kitigaaryuit. This component of the project, Preliminary Study of Kitigaaryuit's Oral History, was carried out in November 1995 to March 31, 1996 This study confirmed that there are elders alive today that still have knowledge of events and past life at Kitigaaryuit. The information and transcripts of the preliminary study is unpublished but will be part of the inventory of material and information collected on Kitigaaryuit. As a result of the preliminary study, it was decided that a more comprehensive project of gathering the oral history/traditional knowledge and historical information on Kitigaaryuit should be done. This work was carried out on July 1996 to May 15, 1997. This phase of the project involved a two week stay in Kitigaaryuit in July (when the mosquito population was at its peak!) and the gathering of historical information available on Kitigaaryuit, During this time, elders were interviewed on site, an archaeological inventory and mapping of cultural features of the site was completed and the gathering of as much information available from places such as the Hudson's Bay Archives in Winnipeg and the National Archives in Ottawa. This report is the transcripts of the interviews done in Inuvialuktun and English with elders while on site at Kitigaaryuit. ... (Au)

V, U, T, R
Archaeology; Artifacts; Elders; Heritage sites; Inuit; Inuit archaeology; Inuit languages; Oral history; Social surveys; Sound recordings; Traditional knowledge

G0812
Kittigazuit region, N.W.T.


Kitigaaryuit Archaeological Inventory and Mapping Project - 1996 : field report   /   Hart, E.J.   Inuvialuit Social Development Program [Sponsor]
Inuvik, N.W.T. : Inuvialuit Social Development Program, 1997.
v, 100, 75 p. : ill., maps ; 28 cm.
(PCSP/PPCP contribution, no. 015-98)
ISBN 0-9683636-0-1
Appendix.
References.
Partial contents: Appendix A: Catalogue of cultural remains at Kitigaaryuit.
ASTIS record 74038 describes the oral history component of this project.
ASTIS record 74037.
Languages: English

... This field report provides an overview of archaeological research undertaken by the Inuvialuit Social Development Program (ISDP) at Kitigaaryuit in the summer of 1996. ISDP is the organization within the Inuvialuit Regional Corporation (IRC) that is responsible for culture and heritage. In 1995 ISDP began a research project focussing on the collection of oral history and traditional knowledge of Kitigaaryuit. Interviews were conducted in the community of Tuktoyaktuk by Florence Nasogaluak. The project was expanded in 1996 to include an archaeological inventory and mapping of the village site and adjacent graveyards. Oral traditions research was continued in bringing elders to the site to relate their knowledge of its history and to assist with the identification of cultural remains. The results of the oral traditions research are currently being written by project director, Cathy Cockney of ISDP [described by ASTIS record 74038]. However, a few details from interview transcripts are presented here. The archaeological and oral traditions research will continue at Kitigaaryuit in 1997 and the results of all the research will be combined and presented in a final report to be produced by mid-1998. ... The objective of the research was to produce an inventory of cultural remains that can be seen at or on the surface of Kitigaaryuit. This information was to be used to produce maps showing the type and distribution of cultural remains that relate to various periods of use of Kitigaaryuit. Conducting the inventory also provided for the opportunity to assess the condition of the remains and note any impacts occurring to them. This would provide information needed by heritage managers to conduct long term monitoring of the site. Kitigaaryuit is currently used by Inuvialuit from Tuktoyaktuk and Inuvik as a seasonal hunting camp for beluga whaling and spring goose hunting. Its historical importance as a cultural centre and the breadth and quantity of cultural remains makeit an ideal location for cultural camps in which young people can learn about Inuvialuit traditions past and present. The array of geographical features, vegetation types and wildlife in the area, when considered with the cultural features makes Kitigaaryuit an ideal setting for a cultural and/or science camp. These same features give Kitigaaryuit great potential for tourism development. Such undertakings must be done cautiously if cultural remains are not to be damaged or destroyed and this inventory and resulting maps provides a necessary first step in assessing the feasibility of such initiatives. ... CONCLUSION: The archaeological survey and mapping at Kitigaaryuit has provided the first detailed picture of the quantity and distribution of cultural remains found there, and is important for learning more about the life and history of the Kitigaaryumiut. It also provided insights into the condition of the remains and types of impacts occurring to both them and the size in general. This information is necessary for future monitoring of the site which will become increasingly important if visitation increases due to the growing awareness that Kitigaaryuit is a National Historic Site. The opportunity now lies with Inuvialuit to decide how they would like to see Kitigaaryuit commemorated and used. This will be addressed by the Inuvialuit Social Development Program through the process of community consultation. The growing attention that is now being focussed on Kitigaaryuit through the current research, and the realization that it was declared a National Historic Site, must be extremely gratifying to those elders who have long known its cultural significance. It has been almost 100 years since Kitigaaryuit was a thriving village. Although it may not be used as a village again, there is great potential for Kitigaaryuit to enter a new period of use. This is one in which it again plays a key role as a place where people young and old can gather to celebrate Inuvialuit culture, history and the land. (Au)

U, V, T, A, I, N, R, H
Anglican Church of Canada ; Archaeology; Archives; Artifacts; Beluga whales; Bones; Buildings; Burial practices; Caribou; Design and construction; Elders; Erosion; Geese; Geographical names; Geographical positioning systems; Graves; Heritage sites; History; Houses; Hudson's Bay Company; Hunting; Inuit archaeology; Inuit languages; Kayaks; Location; Mapping; Maps; Oral history; Outpost camps; Photography; Plant distribution; Plants (Biology); Rites and ceremonies; Sleds; Social surveys; Spatial distribution; Surveying; Tourist trade; Traditional knowledge; Trails; Umiaqs; Villages; Whaling

G0812
Kittigazuit region, N.W.T.


Kitigaaryuit Oral Traditions Research Project 1997 : English translations and transcriptions of interview tapes #1-16   /   Cockney, C.   Inuvialuit Social Development Program [Sponsor]
Inuvik, N.W.T. : Inuvialuit Social Development Program, 1998.
455 p. ; 28 cm.
(PCSP/PPCP contribution, no. 017-98)
ISBN 0-9683636-3-6
Cover title: Kitigaaryuit Oral Traditions Research Project - 1997 : interview transcripts.
The PCSP/PPCP contribution number is incorrectly given as 015-98 in this report. The correct number is 017-98.
Partial contents: Tapes 1A & 1B to 8A & 8B Gordon Akvaviak and Edgar Kotokak; Tapes 9A & 9B to 13A & 13B Laura Raymond; Tapes 14A, 14B & 15A Emmanuel Felix Sr.; Tapes 16A & 16B Winnie Cockney.
ASTIS record 74039 describes the archaeology component of this project.
ASTIS record 74040.
Languages: English

... This report represents the recording of elders' stories, legends and traditional knowledge collected at Kitigaaryuk from August 7 to 10, 1997. Additional transcripts of interviews with Emmanuel Felix Sr. and Winnie Cockney are included in this report as they were interviewed to gather additional information about life at Kitigaaryuk and whale processing methods. These transcripts are a continuation of interviews with elders that began in 1995 to gather the oral history/traditional knowledge of life at Kitigaaryuit and the importance of this place to Inuvialuit history. There are two reports that complement this report: 1) "Preliminary Study of Kitigaaryuit's Oral History" which contains the transcripts of interviews conducted by Florence Nasogaluak in 1995; and 2) "Kitigaaryuit Oral Traditions Research Project - l996, Interview Transcripts" [described by ASTIS record 74038.]. ... The 1997 fieldwork began on July 31, 1997 with a survey of archaeological and cultural features on the mainland across the village called Kitigaaryuk. Elisa Hart conducted the survey from Kuugatchiaq to Kuururyuaq with Don Gardner and myself assisting her. Ms. Hart will also be publishing a report entitled "Kitigaaryuit Archaeological Inventory and Mapping Project - 1996" [i.e., 1997, described by ASTIS record 74039]. Five days were spent at this site and then the camp was moved to Kitigaaryuk to continue the 1996 survey and interviews with elders. Three elders were interviewed on site on August 6-10. About ½ of the tapes were done in English and the ½ done in Inuvialuktun with Florence Nasogaluak interpreting for Cathy, Elisa and Don. Much of the interviews concentrated on description of the grave goods and the processing of whale meat and maktak. Much time and effort was spent on translation, typing and editing of these ranscripts. These transcripts and surveys will be used to complete a Commemorative Statement required under the Historic Sites and Monuments Board of Canada to officially recognize Kitigaaryuit as a National Historic Site. (Au)

V, U, T, R, N
Archaeology; Artifacts; Elders; Food preparation; Graves; Heritage sites; Inuit; Inuit archaeology; Inuit languages; Legends; Oral history; Social surveys; Sound recordings; Traditional knowledge; Translators; Whaling

G0812
East Channel (Mackenzie River) region, N.W.T.; Kittigazuit Bay region, N.W.T.; Kittigazuit region, N.W.T.


Kitigaaryuit Archaeological Inventory and Mapping Project - 1997   /   Hart, E.J.   Inuvialuit Social Development Program [Sponsor]
Inuvik, N.W.T. : Inuvialuit Social Development Program, 1999.
v, 96 p. : ill., maps ; 28 cm.
(PCSP/PPCP contribution, no. 018-98)
ISBN 0-9683636-2-8
Appendices.
References.
Partial contents: Appendix A: A selection of Inuvialuktun words related to material culture at Kitigaaryuit - Appendix B: Preliminary assessment of coastal stability at Kittigazuit Island, Beaufort Sea, NWT / Steven M. Solomon - Appendix C: The vegetation of Kitigaaryuit and Kuugatchiaq / Alan Fehr - Appendix D: Cultural remains at Kuugatchiaq (NiTr-1) - Appendix E: Observations on the skin boats of Kitigaaryuit / Don Gardner.
Report date: December 1999.
ASTIS record 74040 describes the oral history component of this project.
ASTIS records 74041, 74042, and 74043 describe Appendices B, C, and E respectively.
ASTIS record 74039.
Languages: English

Kitigaaryuit, the central gathering place of the Kitigaaryumuit, was occupied for at least 500 years. During the whaling season it was reported that up to 1000 people gathered there for a collective beluga hunt. In winter people gathered for festivities related to the disappearance and eventual return of the sun. Robert McGhee conducted excavations at Kitigaaryuit in 1968 and 1970 (McGhee 1974). Based on the results of his research he nominated it as a National Historic Site and it was declared as such in 1978. No further research, cultural resource management or plans for commemorating the site were undertaken until 1995 when the Inuvialuit Social Development Program (ISDP) began an oral traditions research project focused on the history and use of Kitigaaryuit (Nasogaluak and Cockney 1996). ISDP's program was expanded in 1996 to include an archaeological inventory and mapping of cultural remains at the site (Cockney 1997, Hart 1997, Hart and Cockney 1998). The history of use of the site is outlined in the 1996 field report along with a description of the many cultural remains found there [described by ASTIS record 74037]. This report describes field work undertaken in 1997 at Kitigaaryuit and at an adjacent stretch of coastline to the west. The project had a number of components. We returned to Kitigaaryuit to conduct follow-up work stemming from the 1996 inventory and mapping project. Cathy Cockney brought elders to the site to continue the oral traditions research. A number of other researchers came to Kitigaaryuit to conduct studies needed for the cultural resource management of the site. These included an assessment of coastal processes threatening cultural remains, an inventory of vegetation and assessment of impacts on it that may occur to it from visitation, and a preliminary tourism feasibility study. A survey of an 11 km stretch of coastline immediately west of Kitigaaryuit was conducted. This area is separated from Kitigaaryuit by a 200 m wide channel of the Mackenzie River. We wanted to examine this area as elders reported that the east end of the survey area was once a residential area related to Kitigaaryuit. We wanted to look for sites along the first 7 km of coast as it has place names related to Kitigaaryuit in containing the word root or roots, "Kitigaar." Our survey ended at the site of 3 log cabins and an abandoned Royal Canadian Air Force (RCAF) and United States Air Force Loran (USAF) station known locally as Army Camp. We wanted to know more about the history of these sites, both of which when in use, were incorrectly said to be located at Kittigazuit (Kitigaaryuit). ... The objectives of our field work at Kitigaaryuit were: i. to plot the locations of 10 cultural remains that had been missed on the 1996 maps, ii. to assess which areas of the site are threatened by coastal erosion, iii. to determine the feasibility of developing Kitigaaryuit for tourism, iv. to conduct an inventory of vegetation at the site to detect the impacts of human disturbance on the vegetation, v. to see if the type of vegetation found at the site can be used to determine the presence of archaeological remains at other sites in the area, vi. to examine the nature and extent of cultural remains on the mainland west of Kitigaaryuit where elders reported there was once a residential area, vii. to look for sites in an area where there are named places related to Kitigaaryuit, and viii. to examine the remains of 3 log cabins and an abandoned RCAF/USAF Loran station. ... (Au)

U, V, T, A, I, N, R, H
Aerial photography; Archaeology; Artifacts; Bones; Buildings; Caribou; Coast changes; Creep; Elders; Erosion; Geese; Geographical names; Geographical positioning systems; Graves; Heritage sites; History; Houses; Hunting; Inuit archaeology; Inuit languages; Kayaks; Location; Mapping; Maps; Middens (Archaeology); Military operations; Oral history; Outpost camps; Plant distribution; Plants (Biology); Reindeer husbandry; Shorelines; Sleds; Social surveys; Spatial distribution; Surveying; Tourist trade; Traditional knowledge; Umiaqs; Villages; Waste management; Whaling

G0812
East Channel (Mackenzie River) region, N.W.T.; Kittigazuit Bay region, N.W.T.; Kittigazuit region, N.W.T.


Drainage system behaviour of a High-Arctic polythermal glacier   /   Skidmore, M.L.   Sharp, M.J.
(Papers from the International Symposium on Glaciers and the Glaciated Landscape, held at Kiruna, Sweden, 17-21 August 1998 / Edited by J. Kleman. Annals of glaciology, v. 28, 1999, p. 209-215, ill., 1 map)
(PCSP/PPCP contribution, no. 020-98)
References.
ASTIS record 47200.
Languages: English
Web: doi:10.3189/172756499781821922
Libraries: ACU

Measurements made at John Evans Glacier, eastern Ellesmere Island, Nunavut, Canada in 1994 and 1996 provide new insight into the internal hydrology of poly-thermal glaciers. During the early part of each melt season, supraglacial waters enter the glacier via a crevasse field about 4 km from the terminus and are stored in a subglacial reservoir. Release of the water from the reservoir occurs initially via an artesian fountain on the glacier surface and by upwelling of waters through subglacial sediments at the terminus (event 1). Channelization of the subglacial waters then occurs and water is discharged as an outburst flood (event 2), which releases a considerably larger volume of water than event 1. Thus, drainage of the subglacial reservoir follows a cyclical pattern in which discharge oscillations increase in amplitude over time. The cycle may end with complete reservoir drainage. The total volume of water released was much greater in 1994 than in 1996, primarily because the 1994 melt season was longer and warmer than the 1996 season. Interannual differences in the form of the outflow hydrographs, and in the extent and timing of connections between the subglacial reservoir and marginal melt streams, are linked to variations in the size and rate of growth of the subglacial reservoir. This hydrological behaviour may have important implications for the dynamics of polythermal glaciers. (Au)

F
Chemical properties; Drainage; Glacial melt waters; Glacier lake outbursts; Glaciers; Hydrology; Melting; River discharges

G0813
Ellesmere Island, Nunavut; John Evans Glacier, Nunavut


Saxifragaceae of the Canadian Arctic Archipelago : a contribution to a DELTA database for interactive identification and illustrated information retrieval   /   Aiken, S.G.   Dallwitz, M.J.   McJannet, C.L.   Gillespie, L.J.   Consaul, L.L.
(Canadian journal of botany, v. 76, no. 12, Dec. 1998, p.2020-2036)
(PCSP/PPCP contribution, no. 021-98)
Appendices.
References.
ASTIS record 47288.
Languages: English
Web: doi:10.1139/cjb-76-12-2020
Libraries: ACU

A re-assessment of members of the family Saxifragaceae in the Canadian Arctic Archipelago is presented as a traditional key and annotated checklist that recognizes 17 taxa. The information on which this paper is based is recorded in a developing DELTA database that aims to collect the following data: place of valid publication; synonymy, usually limited to names that have been associated with the Canadian Arctic; common name(s), if applicable; vegetative and floral morphological characters; data on the distribution, including information about the northernmost record of the taxon: habitat preferences of each species; notes on the species as an environmental indicator; indigenous knowledge; and expanded notes conveying additional information. The database also contains maps, illustrations of characters useful for identification, and colour photographs and line drawings of the taxa. Appendices list characters recorded in the database, brief taxonomic notes, and a sample species description. The data are available on the Internet at http://biodiversity.uno.edu/delta/ as natural-language descriptions and as an INTKEY interactive identification and information-retrieval package for Windows. (Au)

H, J
Databases; Electronic data processing; Flowers; Leaves; Plant distribution; Plant taxonomy; Plants (Biology); Saxifraga; Stems; Tundra ecology

G0813
Canadian Arctic Islands


Catchment and lake controls over the formation of varves in monomictic Nicolay Lake, Cornwall Island, Nunavut   /   Lamoureux, S.F.
(Canadian journal of earth sciences, v. 36, no. 9, Sept. 1999, p.1533-1546, ill., maps)
(PCSP/PPCP contribution, no. 025-98)
References.
ASTIS record 47362.
Languages: English
Web: doi:10.1139/cjes-36-9-1533
Libraries: ACU

On the basis of thin-section sedimentology, 137Cs and 210Pb profiles, and the pronounced seasonality of runoff and sediment delivery, sediments from Nicolay Lake, Cornwall Island, Nunavut (77° 46' N, 94° 40' W) are interpreted as varves. In thin section, the laminae are conformable, normally graded units of silt and clay. Depending on the location in the lake, the varves frequently contain one or more subannual rhythmites and inclusions of coarse sand and silt grains. Given the unstratified nature of the lake, the rhythmites are interpreted as products of sediment inflow events derived from rainfall, snowmelt, or mass wasting processes. In the most proximal site, these rhythmites may reflect insolation-driven diurnal variations in sediment transport. Isolated coarse grains in the varves are interpreted as eolian sediments washed off the lake ice cover. The lake is currently isothermal, and persistent ice cover and cold inflow prevent the formation of thermal stratification. The high accumulation rate is a critical factor in varve formation and it is probable that increased sediment yield during the past 500 years has led to the formation of varves, compared to the underlying massive mud that accumulated when deposition was focused inland of the lake during higher relative sea level. Evidence in the catchment indicates that high-elevation deglacial deposits have acted as an important fine-grained sediment source throughout the Holocene. These sediments moved progressively downstream through a series of basins by successive degradation and aggradation controlled by glacioisostatic emergence, hence, limiting the progression of this paraglacial sediment wave to areas upstream of the lake until the late Holocene. These results identify the importance of shifting catchment boundary conditions on sediment yield throughout the Holocene, and also indicate the difficulty of interpreting low-frequency yield variations as the direct consequence of changing climate in similar varve records. (Au)

B, F
Bottom sediments; Cores; Diurnal variations; Geological time; Glaciation; Lakes; Mass wasting; Palaeogeography; Recent epoch; River deltas; Runoff; Sedimentation; Sediments (Geology); Stratigraphy; Stream flow

G0813
Cornwall Island, Nunavut; Nicolay Lake, Nunavut


Cold-climate shattering (1974 to 1993) of 200 glacial erratics on the exposed bottom of a recently drained Arctic lake, Western Arctic coast, Canada   /   Mackay, J.R.
(Permafrost and periglacial processes, v. 10, no. 2, Apr.-June 1999, p. 125-136, ill., maps)
(PCSP/PPCP contribution, no. 026-98)
References.
ASTIS record 47557.
Languages: English
Web: doi:10.1002/(SICI)1099-1530(199904/06)10:2<125::AID-PPP311>3.3.CO;2-C
Libraries: ACU

The shattering of 200 glacial erratics on the exposed bottom of an Arctic lake that drained rapidly, probably in 1955, was studied from 1974 to 1993. Most of the erratics were igneous rocks derived from the Canadian Shield. The erratics, which were unshattered before 1974, had already survived, in varying degrees, at least three prior stages of shattering: first, when many of the rocks were in the thin active layer of the glacial till that covered the area; second, when all of the rocks, after submergence by lake enlargement, underwent annual freeze-thaw cycles under saturated conditions; and third when, after rapid lake drainage, the rocks were exposed to cold sub-aerial climate conditions before being marked for study in 1974. The 200 rocks were checked in 1977, 1978, 1979, 1987, 1988 and 1993. In 1993, the last year of observation, 180 of the original 200 rocks were relocated. The results showed that at least 10 of the 200 rocks had shattered, these being: at least 2 out of about 136 granites; 1 out of about 6 gneisses; 1 out of 2 sandstones; and 6 out of about 22 dolomites. The impervious granites probably hydrofractured from the freezing of water in closed to semi-closed systems or from thermal shocks. Rocks which facilitated the entry of water, such as those with a foliation, schistosity or porosity, broke the most frequently, many probably from ice segregation. Some of the dolomites probably shattered explosively. In support of the ice segregation theory of shattering for some types of rocks, an example is given of present-day ice segregation in a Cretaceous shale at the mouth of nearby Horton River, NWT. (Au)

B, C, F, A
Active layer; Bottom sediments; Cryogenics; Dolomite; Drainage; Frost action; Frost penetration; Frozen ground; Glacial deposits; Gneiss; Granite; Igneous rocks; Lakes; Periglacial landforms; Sandstone; Shale; Thermal expansion; Thermal regimes; Weathering

G0812
Horton River region, N.W.T.


Killing of a muskox, Ovibos moschatus, by two wolves, Canis lupus, and subsequent caching   /   Mech, L.D.   Adams, L.G.
(Canadian field-naturalist, v.113, no. 4, Oct.-Dec. 1999, p. 673-675)
(PCSP/PPCP contribution, no. 030-98)
References.
ASTIS record 48882.
Languages: English
Libraries: ACU

The killing of a cow Muskox (Ovibos moschatus) by two Wolves (Canis lupus) in 5 minutes during summer on Ellesmere Island is described. After two of the four feedings observed, one Wolf cached a leg and regurgitated food as far as 2.3 km away and probably farther. The implications of this behavior for deriving food-consumption estimates are discussed. (Au)

I
Animal behaviour; Animal food; Muskoxen; Predation; Wolves

G0813
Ellesmere Island, Nunavut


"Standing over" and "hugging" in wild wolves, Canis lupus   /   Mech, L.D.
(Canadian field-naturalist, v.115, no. 1, Jan.-Mar. 2001, p. 179-181)
(PCSP/PPCP contribution, no. 031-98)
References.
ASTIS record 50398.
Languages: English
Libraries: ACU

During six summers, I observed "standing over" (SO) and "hugging" in a pack of wild Wolves (Canis lupus) habituated to me. In SO, one Wolf positions its groin above a recumbent Wolf's nose. I observed SO among all yearling and older Wolves for 1-180 seconds (mean = 69 ±46 S.D.; N = 16). SO appeared to be primarily female-oriented and may inform each Wolf of the reproductive status of the other. I observed "hugging" five times and only during years when food competition was minimal. (Au)

I
Animal behaviour; Animal reproduction; Wolves

G0813
Ellesmere Island, Nunavut


Alpha status, dominance, and division of labor in wolf packs   /   Mech, L.D.
(Canadian journal of zoology, v. 77, no. 8, Aug. 1999, p.1196-1203)
(PCSP/PPCP contribution, no. 032-98)
References.
ASTIS record 47423.
Languages: English
Web: doi:10.1139/cjz-77-8-1196
Libraries: ACU

The prevailing view of a wolf (Canis lupus) pack is that of a group of individuals ever vying for dominance but held in check by the "alpha" pair, the alpha male and alpha female. Most research on the social dynamics of wolf packs, however, has been conducted on non-natural assortments of captive wolves. Here I describe the wolf-pack social order as it occurs in nature, discuss the alpha concept and social dominance and submission, and present data on the precise relationships among members in free-living packs, based on a literature review and 13 summers of observations of wolves on Ellesmere Island, Northwest Territories, Canada. I conclude that the typical wolf pack is a family, with the adult parents guiding the activities of the group in a division-of-labor system in which the female predominates primarily in such activities as pup care and defense and the male primarily during foraging and food-provisioning and the travels associated with them. (Au)

I
Animal behaviour; Animal food; Gender differences; Wolves

G0813
Ellesmere Island, Nunavut


Slow growth and decomposition of mosses in Arctic lakes   /   Sand-Jensen, K.   Riis, T.   Markager, S.   Vincent, W.F.
(Canadian journal of fisheries and aquatic sciences, v. 56, no. 3, March 1999, p. 388-393, ill.)
(PCSP/PPCP contribution, no. 033-98)
References.
ASTIS record 47394.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/129.pdf
Web: doi:10.1139/cjfas-56-3-388
Libraries: ACU

Aquatic mosses are often the exclusive form of macrophytic vegetation in Arctic lakes. Despite the cold nutrient-poor water and the short ice-free summer, the mosses form dense stands on the lake bottom down to great depths. The environmental conditions suggest that moss growth and decomposition are extremely slow, but logistical and methodological difficulties have so far precluded direct measurements of the processes. Here, we use temporal changes in the size and density of leaves along the axis of moss shoots collected from different depths in Char Lake and North Lake in the Canadian High Arctic to reconstruct the annual growth and decomposition of the mosses during the past 10-17 years. Our results show low but remarkably constant annual elongation rates (about 10 mm/shoot) in the long-lived shoots that carry green leaves for several years and decompose slowly. Cold temperatures and low nutrient supply in combination with the short Arctic growing season can account for the low growth rate, the low decomposition rates, and the unprecedented longevity of these moss communities relative to other submerged macrophytes. (ASTIS)

H, F, J
Age; Biodegradation; Fresh-water flora; Growing season; Growth; Lakes; Mosses; Temperature

G0813
Char Lake, Nunavut; North Lake, Nunavut


Ecology of Arctic lakes and rivers   /   Vincent, W.F.   Hobbie, J.E.
In: The Arctic : environment, people, policy / Edited by M. Nuttall and T.V. Callaghan. - Amsterdam : Harwood Academic, 2000, ch. 8, p. 197-232, ill., maps
(PCSP/PPCP contribution, no. 034-98)
References.
ASTIS record 76529.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/141.pdf
Libraries: ACU

... The aim of this chapter is to provide an introduction to the literature on inland aquatic ecosystems of the circumpolar Arctic and Subarctic, with emphasis on current research themes in the North American sector. These themes include traditional (and still important) limnological subjects such as habitat structure, species diversity, biological production and food web interactions. Such studies are increasingly supported by novel instruments and methodologies such as remote sensing, underwater profilers and molecular techniques, and by new research strategies. ... (Au)

F, J, E, G, I, H
Atmospheric circulation; Bacteria; Benthos; Biological productivity; Carbon cycling; Climate change; Density; Effects monitoring; Environmental impacts; Fishes; Food chain; Fresh-water biology; Fresh-water ecology; Ice cover; Isotopes; Lake stratification; Lake-atmosphere interaction; Lakes; Light; Microbial ecology; Mosses; Photosynthesis; Phytoplankton; Pollution; Research; Rivers; Temperature; Temporal variations; Zooplankton

G081, G06, G02
Alaska, Northern; Arctic regions; Canadian Arctic; Nunavik, Québec; Subarctic regions; Toolik Lake, Alaska


Community and pigment structure of Arctic cyanobacterial assemblages : the occurrence and distribution of UV-absorbing compounds   /   Quesada, A.   Vincent, W.F.   Lean, D.R.S.
(FEMS microbiology, ecology, v. 28, no. 4, April 1999, p. 315-323, ill.)
(PCSP/PPCP contribution, no. 037-98)
References.
ASTIS record 45203.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/130.pdf
Web: doi:10.1016/S0168-6496(98)00114-7

Three groups of cyanobacterial communities were widely distributed in the benthic environment of lakes, ponds and streams on Ellesmere Island and Cornwallis Island in the Canadian High Arctic: (1) sheets or spherical colonies of Nostoc (up to 20 mm diameter); (2) biofilms up to 7 mm thick, dominated almost exclusively by Oscillatoria; (3) microbial mats up to 8 mm thick containing several taxa, particularly Scytonema and Phormidium. The abundance of heterocystous genera (communities 1 and 3) implies that N2 fixation plays an important role in the nitrogen economy of these ecosystems. Most of the communities were rich in pigments absorbing in the UV-blue end of the spectrum, such as scytonemin and mycosporine-like amino acids. Spectroradiometric analyses of sections of the communities showed that short wavelength radiation did not reach the bottom layer where phycobiliprotein-rich cells were located. This lower community experienced low irradiance in the photosynthetically active radiation band (400-700 nm), restricted to the wavelengths of the yellow-red waveband (550-650 nm). The surface screening of high energy wavelengths may confer an adaptive advantage to these communities which grow under continuous light during the polar summer. (Au)

I, F
Adaptation (Biology); Benthos; Fresh-water ecology; Lakes; Light; Nitrogen cycling; Photoperiodism; Rivers; Tundra ponds

G0813
Cornwallis Island, Nunavut; Ellesmere Island, Nunavut


Carbon fixation by phytoplankton in High Arctic lakes : implications of low temperature for photosynthesis   /   Markager, S.   Vincent, W.F.   Tang, E.P.Y.
(Limnology and oceanography, v. 44, no. 3, May 1999, p. 597-607, ill.)
(PCSP/PPCP contribution, no. 039-98)
References.
ASTIS record 47588.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/126.pdf
Web: doi:10.4319/lo.1999.44.3.0597
Libraries: ACU

Photosynthesis vs. irradiance relationships were determined for phytoplankton communities from seven lakes in the Canadian high Arctic, including ultraoligotrophic Char Lake, nutrient-enriched Meretta Lake, and two meromictic lakes. The derived photosynthetic parameters were low for all samples, with a mean (±SD) light-saturated photosynthetic rate (PBm) of 0.46 (±0.28) g C/g chlorophyll a (Chl a)/h and a mean alpha B (light-limitation parameter) of 1.23 (±0.56) g C/g Chl a m²/mol. The saturation irradiance (Ek) ranged from 50 to 196 µmol quanta/m²/s and was positively correlated with mean irradiance for the water column. Quantum yields for photosynthesis in the Arctic lake phytoplankton were also low (mostly <10 mmol C/mol quanta). An intersystem comparison of alpha B and PBm values with literature data for algae from other cold environments showed that the photosynthetic parameters for phytoplankton in Arctic and Antarctic lakes are three- to sixfold lower than for marine algae, ice algae, and cultures over the same low-temperature range. This may be the result of more severe nutrient stress in high-latitude lakes relative to polar marine environments and to the persistence of nonactive pigments in cold freshwaters. (Au)

H, F, I
Algae; Bathymetry; Carbon; Chlorophyll; Effects of temperature on plants; Fresh-water biology; Lakes; Light; Oxygen; Photosynthesis; Phytoplankton; Plant growth; Plant nutrition; Plant physiology; Salinity; Temperature

G0813
Char Lake, Nunavut; Cornwallis Island, Nunavut; Eleanor Lake, Nunavut; Garrow Lake, Nunavut; Little Cornwallis Island, Nunavut; Meretta Lake, Nunavut; North Lake, Nunavut; Resolute Lake, Nunavut; Sophia Lake, Nunavut


Glacial landform - sediment assemblages in the Canadian High Arctic and their implications for Late Quaternary glaciation   /   Ó Cofaigh, C.   Lemmen, D.S.   Evans, D.J.A.   Bednarski, J.
(Papers from the International Symposium on Glaciers and the Glaciated Landscape, held at Kiruna, Sweden, 17-21 August 1998 / Edited by J. Kleman. Annals of glaciology, v. 28, 1999, p. 195-201, ill., 1 map)
(PCSP/PPCP contribution, no. 040-98)
References.
ASTIS record 47199.
Languages: English
Web: doi:10.3189/172756499781821760
Libraries: ACU

Modern terrestrial glaciers in the Canadian High Arctic range from polythermal to cold-based. Where polythermal glaciers override thick unconsolidated sediment, longitudinal compression and glaciotechtonic thrusting produce thrust-block moraines. In contrast, the dominant geomorphic record of cold-based glaciers consists of lateral and proglacial meltwater channels. Geomorphic and sedimentary evidence indicates that late Quaternary fiord glaciers were also characterized by variations in basal thermal regime. Erratic dispersal trains and striated bedrock record the flow of warm-based ice during the Last Glacial Maximum. Emergent grounding-line fans and morainal banks, deposited during deglaciation, consist of heterogeneous glaciomarine deposits that record well-developed sublgalcial drainage and high sedimentation rates. However, in other fiords, subaqueous outwash and fine-grained glaciomarine deposits are absent and deglaciation is recorded by lateral meltwater channels graded to raised glaciomarine deltas, suggesting these glaciers were predominantly cold-based during retreat. Regionally, deglacial depocentres are located at pinning points within fiords and a prominent belt of glaciogenic landforms at fiord heads records stabilization of ice margins during early Holocene retreat, rather than the limit of late Quaternary glaciation. Collectively, these observations refute previous reconstructions which inferred a climatically controlled switch from cold- to warm-based thermal conditions in fiord glaciers during early Holocene deglaciation, and indicate that the dominant controls on thermal regime were glaciological. (Au)

A, F, B
Deglaciation; Drainage; Glacial deposits; Glacial epoch; Glacial landforms; Glacial transport; Glaciers; Ice caps; Moraines; Quaternary period; Sediment transport; Sedimentation; Sediments (Geology); Thermal regimes

G0813
Axel Heiberg Island, Nunavut; Devon Island, Nunavut; Ellesmere Island, Nunavut; Prince of Wales Island, Nunavut


Forms, response times and variability of relative sea-level curves, glaciated North America   /   Dyke, A.S.   Peltier, W.R.
(Geomorphology, v. 32, no. 3-4, Mar. 2000, p. 315-333, ill., maps)
(PCSP/PPCP contribution, no. 003-99)
ASTIS record 76524.
Languages: English
Web: doi:10.1016/S0169-555X(99)00102-6
Libraries: ACU

Relative sea level curves from glaciated North America reveal coherent spatial patterns of response times. In the Laurentide Ice Sheet area, curve half-lives range from 1.2-1.4 ka at the uplift centre to 1.7-2 ka in a ridge of high values inboard of the glacial limit. Half-lives decline from this ridge to less than 1 ka along the margin. In the Innuitian Ice Sheet area, half-lives are about 2 ka at the uplift centre and decline to less than 1 ka at the margin. The central Laurentide response times are about half those of central Fennoscandia. This accords with the theoretical expectation that central response times are inversely proportional to ice sheet radius for ice loads large enough that rebound at the centre is insensitive to lithospheric thickness. The Innuitian central response time indicates that rebound at the centre of this ice sheet, which is much smaller than the Fennoscandian Ice Sheet, remains sensitive to lithospheric thickness. Radial gradients in response times reflect the increasing influence of the lithosphere at sites increasingly closer to the margin. Along this gradient, rebound progresses as though at the centres of smaller and smaller ice sheets. That is, the effective spatial scale of the ice load decreases toward the margin. Near the glacial limit, postglacial isostatic adjustment is complicated by forebulge migration and collapse. This is seen most strongly in the relative sea level record of Atlantic Canada, which has subsided during the Holocene more than 20 m more than the adjacent American seaboard. The relative sea level history of some areas, notably the St. Lawrence Estuary, is complicated by tectonic processes. (Au)

A, B, I
Beaches; Bones; Bowhead whales; Deglaciation; Driftwood; Flow; Geomorphology; Glacial epoch; Laurentide Ice Sheet; Mollusks; Moraines; Palaeogeography; Radiocarbon dating; Recent epoch; Sea level; Spatial distribution; Subsidence

G08, G0813, G0826, G0827, G0821, G10, G0812, G0828
Admiralty Inlet region, Nunavut; Atlantic Provinces; Canada; Canadian Arctic; Devon Island, Nunavut; Fraser River region, Labrador; Hudson Bay region, Québec; Jones Sound region, Nunavut; Kuujjuarapik, Québec; Labrador; Mackenzie Delta, N.W.T.; Nastapoka, Rivière, region, Québec; Prince Regent Inlet region, Nunavut; Qeqertarsuaq Island, Greenland; Queen Charlotte Islands, British Columbia; St. Lawrence, Gulf of, region, Canada; Vancouver Island, British Columbia; Wellington Channel region, Nunavut


Lack of reproduction in muskoxen and arctic hares caused by early winter?   /   Mech, L.D.
(Arctic, v. 53, no. 1, Mar. 2000, p. 69-71)
(PCSP/PPCP contribution, no. 004-99)
References.
ASTIS record 46266.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic53-1-69.pdf
Web: doi:10.14430/arctic836
Libraries: ACU

A lack of young muskoxen (Ovibos moschatus) and arctic hares (Lepus arcticus) in the Eureka area of Ellesmere Island, Northwest Territories (now Nunavut), Canada, was observed during summer 1998, in contrast to most other years since 1986. Evidence of malnourished muskoxen was also found. Early winter weather and a consequent 50% reduction of the 1997 summer replenishment period appeared to be the most likely cause, giving rise to a new hypothesis about conditions that might cause adverse demographic effects in arctic herbivores. (Au)

I, J, E
Animal food; Animal health; Animal population; Animal reproduction; Hares; Meteorology; Muskoxen; Snow; Winter ecology

G0813
Eureka, Nunavut; Fosheim Peninsula, Nunavut


Yellow Beetle Oral History and Archaeology Project   /   Hart, E.   Cockney, C.   Inuvialuit Development Corporation [Sponsor]
Inuvik, N.W.T. : Inuvialuit Social Development Program, 1999.
v, 85 p. : ill., maps ; 28 cm.
(PCSP/PPCP contribution, no. 005-99)
ISBN 0-9683636-4-4
Appendix.
References.
Partial contents: Appendix A: Summary of conservation treatment on artifacts from Yellow Beetle / A. Bowes and Artifact catalogue for the Yellow Beetle Archaeaology Project.
Report date: March 1999.
ASTIS record 74044 describes the oral history component of this project.
ASTIS record 44896.
Languages: English

... In 1946 the Royal Canadian Air Force (RCAF) joined forces to test a navigation system that would allow aircraft to determine their positions more accurately when flying in the north. This experiment required the building of a chain of Loran (short for "long range navigation") stations, and one of them is the subject of this report. The station, code-named Yellow Beetle, was built near the mouth of the Mackenzie River in 1947 and operated until 1950. It is not related to the Distant Early Warning (DEW) Line radar stations that were constructed in the 1950s. This report outlines the results of oral historical and archaeological research that took place at the station in July, 1998. ... The oral historical research focussed on documenting the perspective of Inuvialuit who worked and lived at the station. ... The report is organized so that a brief historical overview of history of Yellow Beetle is provided first. This is followed by some glimpses of events and life at the station. This information was derived from archival documents and photographs, along with an account of the station as learned from the Reverend George E. Taylor, who worked there in 1949. This is followed by a report on the oral history research and then the archaeological research. A number of recommendations are made regarding future work at Yellow Beetle in relation to contaminants clean-up. Through this research project we have a better understanding of why the station was built, and what it was like for those who worked there. ... We now have a small collection of artifacts that can be used in an exhibit on the history of the station. ... The code name for the station was Yellow Beetle. As it was a secret operation an unclassified name was needed to refer to it. The code name for the entire low frequency test program was Operation Beetle. Individual sites were designated by colour. The Cambridge Bay station was called Blue Beetle .... So, the name Yellow Beetle has no particular significance, and the beetle on the crest was just made up to go with the name. The station was generally referred to by the locational name of Kittigazuit. This name has led to much confusion over the years, as the actual location of Kittigazuit is about 11 km east along to the coast. Kittigazuit is the anglicization of Kitigaaryuit, the Inuvialuktun name for an area on an island that has a 500 year old village and related burial grounds. The Yellow Beetle station is actually located at a creek called Kuururyuaq [i.e., Kuuguryuaq]. The confusion over names of the station and the location gets more complicated. The station is locally known as "Army Camp", although it was an Air Force installation. Some also refer to the creek, Kuururyuaq [i.e., Kuuguryuaq], as Radio Creek. ... (Au)

T, U, V, R, L, M, J, N
Air navigation; Archaeology; Archives; Artifacts; Buildings; DDT; Design and construction; Elders; Employment; Environmental impacts; Fishing; Food; Geopolitics; Heritage sites; Inuit; Inuit archaeology; Middens (Archaeology); Military operations; Mosquitoes; Navigational aids; Oral history; Photograph collections; Pollution; Pollution control; Reclamation; Recreation; Reindeer husbandry; Social interaction; Social surveys; Socio-economic effects; Subsistence; Survival; Tents; Traditional knowledge; Wages; Whaling

G0812
East Channel (Mackenzie River) region, N.W.T.; Yellow Beetle Loran Station, N.W.T.


Yellow Beetle Oral History and Archaeology Project : English translations and transcriptions of interview tapes 1-15   /   Cockney, C.   Inuvialuit Social Development Program [Sponsor]
Inuvik, N.W.T. : Inuvialuit Social Development Program, 1999.
277 p. ; 28 cm.
(PCSP/PPCP contribution, no. 006-99)
ISBN 0-9683636-5-2
Cover title: Yellow Beetle Oral History and Archaeology Project : interview transcripts.
Partial contents: Tapes 1A&B, 2A&B, 3A, 4A&B, 5A&B, 6A&B, and 7A, Joe and Mary Teddy (July 20-21, 1998); Tapes 8A&B and 9A&B, Agnes Nasogaluak (July 22, 1998); Tapes 10A&B, 11A&B, and 12A, Annie Emaghok and Laura Raymond (July 23, 1998); Tapes 13A&B, 14A&B, and 15A, Henry Andreason (July 24, 1998).
Report date: February 1999.
ASTIS record 44896 describes the report by E. Hart and C. Cockney that synthesizes these interviews into the archaeological component of the project.
ASTIS record 74044.
Languages: English

... In early 1998, the Inuvialuit Social Development Program (ISDP) was informed that the old Loran station, known as Army Camp, was to be cleaned up by the Department of Indian and Northern Affairs (DIAND) as part of their DEW Line cleanup program. Since the location was actually the place ISDP had ended its area of study under the Kitigaaryuit Culture History project, ISDP wanted the opportunity to salvage some artifacts prior to the dismantling of the site. ISDP was also interested in collecting more of the oral history of the area as this location was often mentioned in previous interviews with elders. ... The objectives of this oral history component were to: 1. learn about the experiences or Inuvialuit working at the station; 2. learn more about the activities conducted by the RCAF and USAF at the station; 3. combine the various sets of information learned through archival and oral history research to better understand this chapter in the history of Inuvialuit and Canadian history. ... This report ... is the translation and transcriptions of the elders' taped interviews. ... The area of study, which is located 12 km south of Kitigaaryuit, is known by various names. The name "Yellow Beetle" derived from the code letters YB used by the RCAF/USAF when they operated a Loran station at the site. Local people, because of the USAF/RCAF activities in the area, applied the name "Army Camp" to the location. The traditional name for the area is Kuururyuaq. Elder Laura Raymond said that the name refers to the big creek running into the tributary of the Mackenzie River. Elisa Hart provides the same meaning for this name in an unpublished report. The creek is also known as Radio Creek .... At Kuururyuaq, there are three log cabins that were built by the reindeer herders in the l930s. These houses were abandoned for a period of time until the aboriginal people hired by the Air Force fixed up and moved into the houses. They lived in them until the station shut down. Some Inuvialuit employees also lived in tent frames on the east side of the road. After the Yellow Beetle site was closed, reindeer herders and their families returned to Kuururyuaq in the 1950s and stayed in the log cabins. Although reindeer herding and the USAF/RCAF activities in the area are unrelated, including part of the history of reindeer herding was necessary in order to gain a better understanding of the uses of the three log cabins at the site. ... The field work for the Yellow Beetle Oral History and Archaeology Project was held from July 19-26, 1998. The area of study included the log cabins, the Yellow Beetle site, the tent frame village site, the hill with sand pit, the gorge with waste barrels and the beach area from the end of the road up to the dock and airplane location. ... A total of six elders were interviewed on site by the author. Elisa Hart and Barbara Zeeb from ESG [Environmental Sciences Group] participated in the interviews when they required specific information from the elders. Three elders were from Inuvik and they are Agnes Nasogaluak, Joe and Mary Teddy. Three elders were from Tuktoyaktuk and they are Annie Emaghok, Laura Raymond and Henry Andreason. ... The elders lived on site at various times. Henry Andreason actually lived at the Yellow Beetle site during the initial start-up of the station and then moved to the tent frame village when more Inuvialuit were hired to work at the station. Joe and Mary Teddy lived in the tent frame village along with other families. Annie Emaghok lived in one of the log cabins in the l950s when her husband. Adam, was a reindeer herder in the area. Agnes Nasogaluak and Laura Raymond never actually lived at the site but visited the area either when Yellow Beetle or reindeer herding was in operation. The elders were recorded on tapes which are stored in the ISDP office in Inuvik. All elders were primarily asked the same slate of questions that are incorporated in the transcripts. ... (Au)

V, U, T, R, N, M
Accidents; Archaeology; Buildings; Elders; Employment; Geographical names; Houses; Inuit; Inuit archaeology; Inuit languages; Military operations; Oral history; Photograph collections; Pollution; Reindeer husbandry; Sewage disposal; Social surveys; Sound recordings; Tents; Traditional knowledge; Translators; Wages ; Waste management

G0812
East Channel (Mackenzie River) region, N.W.T.; Yellow Beetle Loran Station, N.W.T.


Late Quaternary glacial history of Lake Hazen basin and eastern Hazen Plateau, northern Ellesmere Island, Nunavut, Canada   /   Smith, I.R.
(Canadian journal of earth sciences, v. 36, no. 9, Sept. 1999, p.1547-1565, ill., maps)
(PCSP/PPCP contribution, no. 008-99)
References.
ASTIS record 47363.
Languages: English
Web: doi:10.1139/cjes-36-9-1547
Libraries: ACU

The glacial history of the broad interior of northeastern Ellesmere Island is first documented here. Studies of glacial geomorphology and marine and lacustrine sedimentology indicate that the region was inundated by cold-based ice emanating from the Grant Land Mountains sector of the Innuitian Ice Sheet during the last glacial maximum. Retreat of coalescent, marine-based Ellesmere and Greenland ice from Robeson Channel had started by 10.1 ka BP and reached the mouths of many fiords along southeast Hazen Plateau by 8 ka BP. Proglacial meltwater channels emanating from plateau ice caps, crosscut lateral meltwater channels marking the retreat of Grant Land Mountain ice. The crosscutting is interpreted to reflect an early Holocene growth of plateau ice caps concurrent with the retreat of marine-based margins. This suggests that initial regional ice retreat was eustatically controlled. Stabilization of glacier margins at the heads of fiords occurred by 7.5-7 ka BP, after which land-based margins retreated as little as 10 km by 6 ka BP. Across much of northeastern Hazen Plateau, however, Grant Land Mountain ice retreated more rapidly. This more rapid retreat was accentuated by the impoundment of proglacial lakes against the plateau to the south and the subsequent breakup of ice by calving. Glaciers continued to occupy much of Lake Hazen Basin at 5.3 ka BP, after which they broke up rapidly in a proto-Lake Hazen, retreating to margins at, or behind, those of the present by 5 ka BP. (Au)

A, B
Climate change; Deglaciation; Glacial geology; Glacial melt waters; Glaciation; Glaciers; Ice caps; Moraines; Palaeogeography; Physical geography; Quaternary period; Radiocarbon dating

G0813, G10, G09
Greenland; Hazen, Lake, region, Nunavut; Robeson Channel, Greenland/Nunavut


Reindeer days remembered   /   Hart, E.J.   Northern Oil and Gas Action Program (Canada) [Sponsor]   Inuvialuit Cultural Resource Centre [Sponsor]   Prince of Wales Northern Heritage Centre [Sponsor]   Northwest Territories. Dept. of Education, Culture and Employment [Sponsor]
Inuvik, N.W.T. : Inuvialuit Cultural Resource Centre, 2001.
112 p. : ill., maps ; 28 cm.
(PCSP/PPCP contribution, no. 009-99)
ISBN 0-9683636-7-9
References.
ASTIS record 54988.
Languages: English
Libraries: ACU

... This book is written for a number of audiences. It is meant for the elders and their families who took part in the reindeer industry. We hope that elders may use it to explain their experiences to their children or grandchildren. We tried to make it very visual in format to facilitate such discussions. The book is also meant as an overview of the reindeer industry that can be used in high school classes on local history and geography. Teachers can expand on the topics of interest to them. Elders or other experts on topics touched on in the book could be invited into the classroom to provide their knowledge and perspectives. We also hope that the book will be of interest to the general public. ... The history of the reindeer industry in the Beaufort/Mackenzie Region is very complex. Among the many different people and agencies involved were government employees, Inuvialuit, Inupiat from Alaska, trainees from Kitikmeot Region of the Central Arctic, a small number of Gwich'in, and Saami from Norway. This book is not meant to reflect all of their views. It is meant to provide insights into the experience of Inuvialuit reindeer herders in the early days of the reindeer industry. It also provides glimpses into the experience of herders' families. It focuses on the time when herders, on skis or on foot, kept a constant watch over the herds, from 1935 to approximately 1964. Background information was gathered through research of archival and published documents. ... (Au)

V, T, N, I, H, R
Animal behaviour; Animal distribution; Animal food; Animal migration; Antlers; Caribou; Curricula; Dogs; Education; Elders; Employment; Food; Government; Grasses; Gwich'in Indians; Hide preparation; History; Income; Internal migration; Inuit; Lichens; Meat industry; Mosquitoes; Native peoples; Oral history; Photograph collections; Reindeer; Reindeer husbandry; Saami; Seasonal variations; Shrubs; Skiing; Social conditions; Social policy; Starvation; Traditional knowledge; Wildlife habitat; Wildlife management; Wolves

G0812
Anderson River region, N.W.T.; Anderson River, N.W.T.; Inuvialuit Settlement Region, N.W.T./Yukon; Mackenzie Delta, N.W.T.; Reindeer Station region, N.W.T.; Reindeer Station, N.W.T.


Salinization of permafrost terrain due to natural geomorphic disturbance, Fosheim Peninsula, Ellesmere Island   /   Kokelj, S.V.   Lewkowicz, A.G.
(Arctic, v. 52, no. 4, Dec. 1999, p. 372-385, ill., maps)
(PCSP/PPCP contribution, no. 010-99)
References.
ASTIS record 45894.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic52-4-372.pdf
Web: doi:10.14430/arctic942
Libraries: ACU

Efflorescences (surface salt accumulations) are common on the Fosheim Peninsula and elsewhere in the Canadian Arctic Archipelago, especially at elevations below the Holocene marine limit, and cover up to 9% of the terrain in the vicinity of lower Hot Weather Creek. They are most extensive on naturally disturbed slopes and in floodplain locations. More than 75% of efflorescences are related to geomorphic disturbances (active-layer detachment sliding, retrogressive thaw slumping, and gullying), which initiate the causal chain of (1) surface erosion; (2) local degradation of permafrost; (3) contact between supra-permafrost groundwater and soluble ions previously held within frozen sediments; (4) increase in total dissolved-solids concentrations in slope surface runoff; and (5) depending on the degree of channelization of drainage and the slope profile, transport of dissolved solids directly to the stream system or their redistribution and accumulation downslope. Concentrations of Na+ in surface runoff reached almost 5 g/l during summer 1996 at a recent (1988) detachment slide scar in marine sediments. These concentrations are sufficiently high to negatively affect most terrestrial arctic plant species. Soluble Na+ levels within the active layer suggest that concentrations in slope runoff will remain elevated for several decades. Climatic warming, if it causes an increase in annual thaw depths or in the frequency and extent of geomorphic disturbances, could also result in active layer salinization within areas of salt-rich permafrost, such as in marine surficial deposits. (Au)

C, F, A, E, H, J
Active layer; Climate change; Creep; Drainage; Effects of climate on permafrost; Environmental impacts; Frozen ground; Geomorphology; Mass wasting; Permafrost; Plants (Biology); Runoff; Salinity; Sediment transport; Slopes; Thaw flow slides

G0813
Fosheim Peninsula, Nunavut


Thermokarst sediments and sedimentary structures, Tuktoyaktuk coastlands, western Arctic Canada   /   Murton, J.B.
(Global and planetary change, v. 28, no. 1-4, Feb. 2001, p. 175-192, ill., maps)
(PCSP/PPCP contribution, no. 011-99)
References.
ASTIS record 73753.
Languages: English
Web: doi:10.1016/S0921-8181(00)00072-2
Libraries: ACU

Abrupt climate warming during glacial-interglacial transitions promotes regional thermokarst activity in areas of ice-rich permafrost. The ensuing thaw-related processes of melt-out, soft-sediment deformation and resedimentation may produce widespread thermokarst sediments and sedimentary structures. Examples of the most distinctive thermokarst sediments and sedimentary structures from the Tuktoyaktuk Coastlands, western Arctic Canada, comprise: (1) soft-sediment deformation structures (thermokarst involutions) in a palaeoactive layer; (2) ice-wedge casts and composite-wedge casts; (3) peaty to sandy diamicton deposited mainly by debris flows in retrogressive thaw slumps; and (4) a basal unit of diamicton and/or impure sand in some thermokarst-basin sequences, deposited by progradation of resedimented materials in thermokarst lakes. Many of the thermokarst sediments and sedimentary structures in the Tuktoyaktuk Coastlands formed as a result of rapid climate warming during the last glacial-interglacial transition, although some continue to form at present due to local (non-climatic) factors. Identification of thermokarst sediments and sedimentary structures in the geological record requires evidence for the thaw of excess ice. Direct evidence for the former occurrence of excess ice includes: (1) ice-wedge casts; (2) composite-wedge casts; (3) lenticular platy microstructures in frost-susceptible sediment; (4) certain near-surface brecciation of frost-susceptible bedrock; and (5) ramparted depressions attributed to the decay of frost mounds. Indirect evidence for former excess ice results where thaw consolidation initiates soft-sediment deformation or gelifluction. (Au)

C, A, E, B, F
Active layer; Bottom sediments; Climate change; Coasts; Creep; Deformation; Deglaciation; Drainage; Frost mounds; Glacial epoch; Glaciation; Ground ice; Ice wedges; Lakes; Laurentide Ice Sheet; Mass wasting; Melting; Palaeoclimatology; Palaeogeography; Peat; Permafrost; Pleistocene epoch; Recent epoch; Sand; Sedimentary structures; Sedimentation; Sediments (Geology); Spatial distribution; Stratigraphy; Thaw flow slides; Thawing; Thermokarst; Topography

G0812
Richards Island, N.W.T.; Summer Island, N.W.T.


Late Quaternary glacial histories and Holocene paleoenvironmental records from northeast and southwest Ellesmere Island, Nunavut, Canada   /   Smith, I.R.   England, J. [Supervisor]
Edmonton, Alta. : University of Alberta, 1998.
215 p.
(ProQuest Dissertations & Theses publication, no. NQ34836)
(PCSP/PPCP contribution, no. 012-99)
ISBN 0-612-34836-9
Thesis (Ph.D.) - University of Alberta, Edmonton, Alta., 1998.
The citation and abstract information in this record is used with the permission of ProQuest Information and Learning Company. Further reproduction is prohibited without permission. Copies of dissertations may be obtained from UMI® Dissertation Services, 300 North Zeeb Road, Ann Arbor, MI 48106-1346 USA. Telephone: 734-761-7400. Web-page: wwwlib.umi.com/dissertations.
References.
Not seen by ASTIS. Citation from PQDT.
ASTIS record 53040.
Languages: English
Libraries: OONL

Ice-free areas beyond the limits of the last glaciation have been proposed for much of Ellesmere Island. This hypothesis is addressed by reconstructing the late Quaternary glacial history of Lake Hazen Basin and eastern Hazen Plateau, and by coring extant lake basins beyond proposed ice margins. Diatom records from these lakes, and stable isotope records from emergent basins on Hoved Island, southwest Ellesmere Island, were used to assess Holocene environmental changes in the High Arctic. Lateral meltwater channels, moraines and other geomorphic evidence indicate that a large trunk glacier emanating from the Grant Land Mountains coalesced with Agassiz and Greenland ice, inundating Hazen Plateau. The configuration of deglacial margins related to the trunk glacier, Holocene ice-contact deltas in Robeson Channel, and cosmogenic 36Cl dating of erratics, indicate that this occurred during the last glaciation. Thus, ice-free regions did not exist in the Lake Hazen region. Breakup of marine-based ice margins between 9 and 8 ka BP led to a retreat of Grant Land Mountain trunk ice, and deglaciation of outermost Hazen Plateau. Plateau ice caps, however, persisted and expanded over highland regions in early Holocene. Between 7 and 6 ka BP, ice retreated to the heads of regional fiords and valleys, after which it remained stable. Breakup of ice within the proto-Lake Hazen basin occurred between 5.3 and 5 ka BP, at which point Grant Land Mountain ice had retreated to near its modern limits. Diatom abundances serve as a proxy record of summer lake ice cover. Results from the Lake Hazen region indicate a gradual climatic amelioration between 5 and 4 ka BP. The greatest reduction in ice cover occurred between 4 and 3 ka BP, after which, a cooling led to a decline in diatom abundances in higher elevation lakes, while those lower down maintained high levels until ~2 ka BP. Basal diamicts in cores from two lakes on Hoved Island records the retreat of formerly grounded ice in central Baumann Fiord ~9.3 ka BP. Isotopic records of Lobatula lobatulus detail a stepped ice retreat during early to mid-Holocene, beyond the resolution of previous studies of postglacial emergence. (Au)

B, E, H, A, F, J
Bottom sediments; Cores; Deglaciation; Diatoms; Geological time; Glacial landforms; Glacial melt waters; Glaciation; Ice caps; Ice cover; Isotopes; Lakes; Moraines; Palaeoclimatology; Palaeoecology; Palaeogeography; Quaternary period; Recent epoch; Refugia; Theses

G0813, G0815, G09
Baumann Fiord, Nunavut; Ellesmere Island, Nunavut; Hazen, Lake, region, Nunavut; Hoved Island, Nunavut; Robeson Channel, Greenland/Nunavut


Leadership in wolf, Canis lupus, packs   /   Mech, L.D.
(Canadian field-naturalist, v.114, no. 2, Apr.-June 2000, p. 259-263)
(PCSP/PPCP contribution, no. 013-99)
References.
Two publications have PCSP/PPCP contribution number 013-99. The other one has not been added to ASTIS yet.
ASTIS record 48884.
Languages: English
Libraries: ACU

I examine leadership in Wolf (Canis lupus) packs based on published observations and data gathered during summers from 1986 to 1998 studying a free-ranging pack of Wolves on Ellesmere Island that were habituated to my presence. The breeding male tended to initiate activities associated with foraging and travel, and the breeding female to initiate, and predominate in, pup care and protection. However, there was considerable overlap and interaction during these activities such that leadership could be considered a joint function. In packs with multiple breeders, quantitative information about leadership is needed. (Au)

I
Animal behaviour; Animal reproduction; Predation; Wolves

G0813
Ellesmere Island, Nunavut


The Early Devonian (Pragian) zosterophyll, Bathurstia denticulata Hueber   /   Kotyk, M.E.   Basinger, J.F.
(Canadian journal of botany, v. 78, no. 2, Feb. 2000, p. 193-207, ill., 1 map)
(PCSP/PPCP contribution, no. 014-99)
References.
ASTIS record 48371.
Languages: English
Web: doi:10.1139/cjb-78-2-193
Libraries: ACU

Approximately 86 specimens of Bathurstia denticulata Hueber were collected from upper Bathurst Island and lower Stuart Bay beds of Bathurst Island, Canadian Arctic Archipelago. Bathurstia was a component of a zosterophyll-dominated flora of Pragian age (Lower Devonian) that existed at low paleolatitudes in northern Canada. The large collection of well-preserved materials permits reconstruction of the plant as a robust scrambler of about 30 cm in height. Stems bear short, shelf-like emergences in two rows, and branch isotomously, although sparsely. Rooting organs, representing some of the oldest known for land plants, arise from the main aerial axes, although they are also associated with small, subordinate shoots interpreted as plantlets. Numerous specimens are fertile, with sporangia borne in dense terminal spikes. Spikes include two rows of overlapping, discoid sporangia. Isospores are round and featureless, and assignable to the genus Calamospora. While Bathurstia apparently originated from among the isotomously branching bilaterally symmetrical zosterophylls, the phylogenetic relationships of Bathurstia to known taxa is unclear, although some resemblance to Serrulacaulis, Barinophytaceae, and the Gosslingiaceae can be documented. Bathurstia denticulata is now one of the best known of early land plants, and contributes significantly to our understanding of zosterophylls and their role in Early Devonian vegetation. (Au)

B, H
Devonian period; Evolution (Biology); Palaeobotany; Palynology; Plant taxonomy; Roots; Spores; Stems

G0813
Bathurst Island, Nunavut


Degradation as a loss mechanism in the fate of alpha-hexachlorocyclohexane in Arctic watersheds   /   Helm, P.A.   Diamond, M.L.   Semkin, R.   Bidleman, T.F.
(Environmental science & technology, v. 34, no. 5, Mar. 1, 2000, p. 812-818, ill., 1 map)
(PCSP/PPCP contribution, no. 016-99)
References.
ASTIS record 50764.
Languages: English
Web: doi:10.1021/es990688j
Libraries: ACU

Water extracts of samples collected from Amituk Lake in July-August, 1994 and samples collected at Char and Meretta Lakes in July 1997 were analyzed for enantiomers and concentrations of alpha-HCH to estimate the extent of biodegradation in watersheds in the Canadian High Arctic. (+)/(-)-alpha-HCH enantiomer ratios (ERs) in three streams entering Amituk Lake ranged from racemic values of 1.01 in snow to 0.36 in meltwater. Lower ERs were promoted by warmer temperatures and increased contact with stream substrates during low streamflows, especially biologically productive substrates. Most alpha-HCH degradation occurred during peak runoff when ERs were 0.95-0.80, rather than later in summer when ERs reached their minimum. Approximately 7% of alpha-HCH in the Amituk Lake basin was enantioselectively degraded prior to entering the lake. ERs within Amituk Lake are controlled by meltwater inputs rather than within lake degradation and clearly illustrate the riverine-like nature of high arctic lakes. Differences in lake alpha-HCH inventory from end of summer 1993 to spring 1994 indicate that from 33 to 61% of alpha-HCH within the lake may have been lost via nonenantioselective microbial degradation at a rate ranging from 0.48 to 1.13/y. (Au)

H, J, F
Benthos; Biodegradation; Chemical properties; HCH; Lakes; Measurement; Optical properties; River discharges; Rivers; Seasonal variations; Snow; Snowmelt; Water pH; Water pollution; Watersheds; Winter ecology

G0813
Amituk Lake region, Nunavut; Amituk Lake, Nunavut; Char Lake region, Nunavut; Char Lake, Nunavut; Meretta Lake region, Nunavut; Meretta Lake, Nunavut


Control of biological exposure to UV radiation in the Arctic Ocean : comparison of the roles of ozone and riverine dissolved organic matter   /   Gibson, J.A.E.   Vincent, W.F.   Nieke, B.   Pienitz, R.
(Arctic seas : currents of change / Sponsored by Mystic Aquarium. Arctic, v. 53, no. 4, Dec. 2000, p. 372-382, ill., map)
(PCSP/PPCP contribution, no. 018-99)
References.
ASTIS record 47351.
Languages: English
Web: http://pubs.aina.ucalgary.ca/arctic/Arctic53-4-372.pdf
Web: doi:10.14430/arctic868
Libraries: ACU

Reports of severe stratospheric ozone depletion over the Arctic have heightened concern about the potential impact of rising ultraviolet-B (UV-B) radiation on north polar aquatic ecosystems. Our optical measurements and modelling results indicate that the ozone-related UV-B influence on food web processes in the Arctic Ocean is likely to be small relative to the effects caused by variation in the concentrations of natural UV-absorbing compounds, known as chromophoric dissolved organic matter (CDOM), that enter the Arctic basin via its large river inflows. The aim of our present study was to develop and apply a simple bio-optical index that takes into account the combined effects of attenuation by atmospheric ozone and water column CDOM, and photobiological weighting for high-latitude environments such as the Arctic Ocean. To this end, we computed values for a biologically effective UV dose rate parameter ("weighted transparency" or T*) based on underwater UV measurements in high-latitude lakes and rivers that discharge into the Arctic Ocean; measured incident UV radiation at Barrow, Alaska; and published biological weighting curves for UV-induced DNA damage and UV photoinhibition of photosynthesis. The results underscore how strongly the Arctic Ocean is influenced by riverine inputs: shifts in CDOM loading (e.g., through climate change, land-use practices, or changes in ocean circulation) can cause variations in biological UV exposure of much greater magnitude than ozone-related effects. (Au)

E, D, F, H, J
Climate change; Colored dissolved organic matter; Environmental impacts; Food chain; Genetics; Ocean currents; Ozone; Phytoplankton; River discharges; Ultraviolet radiation

G03, G06, G14
Arctic Ocean; Barrow, Alaska; Sibir', Russian Federation


Holocene vegetation history of Banks Island, Northwest Territories, Canada   /   Gajewski, K.   Mott, R.J.   Ritchie, J.C.   Hadden, K.
(Canadian journal of botany, v. 78, no. 4, Apr. 2000, p. 430-436, ill., 1 map)
(PCSP/PPCP contribution, no. 019-99)
References.
ASTIS record 48372.
Languages: English
Web: doi:10.1139/cjb-78-4-430
Libraries: ACU

Four pollen diagrams from Banks Island, Northwest Territories, provide the first records of the postglacial vegetation of the region. Chronologies are estimated from radiocarbon dates and by correlation of the exotic-pollen curves to data from the mainland. The pollen stratigraphies from all sites can be divided into three zones, where the middle zone, dating from 7000 to 2000 BP, corresponds to the warmest time. Although both the first and third zones correspond to cooler periods, the vegetation of the earliest zone was not identical to that of the latest, indicated by lower frequencies of key pollen types such as those of Dryas and Saxifraga. (Au)

B, H, J
Bottom sediments; Coring; Lakes; Palaeobotany; Palaeoecology; Palynology; Plant distribution; Plants (Biology); Quaternary period; Radiocarbon dating; Stratigraphy

G0812
Banks Island, N.W.T.


Spectral light attenuation and the absorption of UV and blue light in natural waters   /   Markager, S.   Vincent, W.F.
(Limnology and oceanography, v. 45, no. 3, May 2000, p. 642-650, ill.)
(PCSP/PPCP contribution, no. 023-99)
References.
ASTIS record 48541.
Languages: English
Web: http://www.cen.ulaval.ca/warwickvincent/PDFfiles/137.pdf
Web: doi:10.4319/lo.2000.45.3.0642
Libraries: ACU

The spectral pattern of light attenuation in the ultraviolet (UV) and blue region (360-500 nm) was analyzed for seven high Arctic lakes. The best description of Kd versus wavelength was obtained with an exponential model similar to the model used for absorption by chromophoric dissolved organic compounds (CDOM) but with an additional parameter (Kback) that accounts for background scattering: Kd(lambda) = Kd(lamda o)e S(lambda o-lambda) + Kback, where Kd(lambda) is the diffuse vertical attenuation coefficient at wavelength lambda and S is the exponential slope parameter that characterizes the decrease in attenuation with increasing wavelength. The inclusion of the background parameter gave a significantly better fit and eliminated the systematic deviations over the spectrum that occur in the absence of Kback. The resultant S values (mean = 17.4/µm) were on average 47% higher than values calculated without a background parameter, and were more sensitive to between-lake differences. The same pattern was found when S was estimated from spectral Kd values in three literature data sets, so the new equation will generally increase the estimated values of S based on Kd and provide a more accurate guide to intersystem variability. A compilation of literature data for S (based on Kd and the new equation or on absorbance) showed that its mean value (±SE) is significantly higher in freshwaters (17.1 ±0.7/µm) than in the sea (14.0 ±0.4/µm). The variability in S was highest for low values of Kd or alpha (340 nm values below 3/m). This pattern may be due to instrument-related problems or more likely represents the real variability in the optical properties of CDOM in low colored systems. The analysis showed that S can vary significantly between and within systems (overall range = 9.2-36.2/µm) and that the value obtained also depends on the method of calculation, the wavelength range, and the type of optical measurement. (Au)

F
Colored dissolved organic matter; Forecasting; Lakes; Light; Mathematical models; Optical properties; Surface properties; Ultraviolet radiation; Water masses

G0813, G0826
Char Lake, Nunavut; Eleanor Lake, Nunavut; Garrow Lake, Nunavut; Meretta Lake, Nunavut; North Lake, Nunavut; Nunavik, Québec; Resolute Lake, Nunavut; Sophia Lake, Nunavut


Major end moraines of Younger Dryas age on Wollaston Peninsula, Victoria Island, Canadian Arctic : implications for paleoclimate and for formation of hummocky moraine   /   Dyke, A.S.   Savelle, J.M.
(Canadian journal of earth sciences, v. 37, no. 4, Apr. 2000, p. 601-619, ill., maps)
(PCSP/PPCP contribution, no. 024-99)
ASTIS record 50517 describes a discussion of this paper; ASTIS record 50516 describes the reply to the discussion.
References.
ASTIS record 48491.
Languages: English
Web: doi:10.1139/cjes-37-4-601
Libraries: ACU

Some of the most extensive and massive end moraines of Younger Dryas age (11-10 14C ka BP) yet recognized in North America occur on Wollaston Peninsula of Victoria Island. On the western part of the peninsula, numerous closely spaced end moraines formed in the interval starting 11 100 ± 100 radiocarbon years ago and ending about 10 500-10 200 years ago. Net recession was generally slow throughout and punctuated by moraine-building and at least two readvances. Recession is mapped with a resolution that is approximately decadal. The moraines form an orderly, nested succession and are consistently associated with westward shedding of meltwater, which formed a sequence of marine-limit deltas. We lack firm, independent proxy-climate evidence needed to assess whether these moraines formed because of cold Younger Dryas climate, rather than because of controls such as topographic setting and water depth, but climatic control seems probable. The moraines evidently retain glacier ice cores, as do most similarly large moraines in the Canadian Arctic Archipelago and northern mainland. They formed along active ice margins when the glacier mass balance on average was only slightly negative. Future melting of ice cores would produce regional hummocky moraine and much basal meltout till more than 10 000 years after deglaciation. Some southern areas of hummocky moraine may have originated as ice-cored moraines formed by active ice margins rather than from extensive regional stagnation. (Au)

B, F, A, E
Cores; Deglaciation; Effects of climate on ice; Geology; Glacial landforms; Glaciers; Hummocks; Ice sheets; Mass balance; Minerals; Moraines; Palaeoclimatology; Permafrost

G0812, G0813, G0815
Dolphin and Union Strait, N.W.T./Nunavut; Kugaluk River (70 00 N, 114 36 W) region, N.W.T./Nunavut; Prince Albert Sound, N.W.T.; Victoria Island, N.W.T./Nunavut; Wollaston Peninsula, N.W.T./Nunavut


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