... It is the contention of this present note that the West Greenland salmon fishery at least, and probably the other two as well, have come into existence because the salmon themselves have quite recently shifted their sea-life feeding area in response to marine climatic change. The salmon which now appear in west Greenland waters swim very close to the surface and are taken in surface drift nets. The West Greenland waters have been fished and hunted for some four centuries. ... It is entirely unreasonable to believe that, had the salmon been in these waters during such a period of time, they could have escaped detection and exploitation long since. ... Marine (hydrospheric) climates differ from atmospheric climates in that the response of the living populations associated with marine climate changes is immediate, at least as regards planktonic and nektonic communities: there is clearly a lag in the response of benthonic attached and in-faunal communities. We have abundant evidence of drastic changes in the marine climate of the North Atlantic and Subarctic area, particularly in West Greenland waters, during the past century. The increase in temperature since about 1915, which lasted into the 1940s, and brought the Atlantic cod fishery into existence in that region, is especially well documented .... It may be assumed that one selective advantage in the evolution of salmon migration is the attainment of marine regions of high food production; such regions are not stationary in the long term, or even in the comparatively short term, but are dependent on patterns of nutrient production and advection, which are in turn dependent on the changing pattern of wind and current. ... The patterns of migration, and of breeding area, of many marine animals have changed most significantly in recent decades in association with, but not necessarily directly caused by, change in marine climate .... It is therefore reasonable to search for means of navigation, in terms of information used by the migrants, which have also changed during the same period. Of the means so far considered, only two, those of the electric field and of olfactory information, change rapidly enough to be relevant in the present context. If ocean currents carry their own identifying smells and tastes ... then olfactory information may well be involved, but it is the possibility of the relevance of the electric field that is put forward here. It has been suggested by several workers ... that oceanic electrical information may be used by migrating animals .... The potentials developed by the passage of ocean currents through the earth's magnetic field are proportional to the velocity and transport of the current, and therefore the pattern must change as current velocities change; and changes in transport and velocity are clearly involved in changes in hydrospheric climate .... If electric fields are used in migration of fish, therefore, we should expect the migrational routes and termini to change with the climatic cycle. ... Shifts in the distribution and migration of marine exploitable species are of immense economic and international importance, and underline the urgent necessity for far better understanding of entire processes controlling changes in marine climate. ...
The amount of animal matter in the stomach contents of tree sparrows (Spizella arborea) collected at Churchill, Manitoba, increased from June until the middle of July but quickly dropped off in August. Chief food items were seeds of 6 species of Carex; seeds, flowers and fruits of Empetrum and Vaccinium; adult Diptera and Araneida; and larvae of Coleoptera and Lepidoptera. From available foods tree sparrows selected several species of Carex and ignored others. Snails though abundant were not eaten, and several larval insect forms were selected out of proportion to their occurrence in availability samples. The gross caloric value of the average summer diet was 5211 cal./g. dry weight and the kcal./day or the equivalent of 5.06 and 6.33 g. dry wt. of diet items. On the basis of food supply it is doubtful that gross energy of available foods limits the breeding density of tree sparrows at Churchill.
Three transverse profiles across a large pressure ridge located in the Beaufort Sea are presented. The ridge sail extended 4m. above sea level and the ridge keel 13 m. below. The cross-sections of the ridge keel can be described as roughly semi-circular. This suggests that form drag coefficients for flow transverse to the long axes of multi-year ridges may be as high as 0.8. Examination of several salinity, temperature and brine-volume profiles shows that much of the ice in the ridge has a very low salinity and is quite strong. All the inter-block voids that initially existed in the ridge at the time of its formation have been completely filled with ice. These observations, coupled with icebreaking experience indicate that multi-year ridges are, indeed, significant obstacles to even the largest icebreaking ship and should be avoided if possible. A very large first year ridge with a sail height of 12.8 m. is also described. This is the largest free-floating ridge yet measured.
The Canadian Arctic marine flora is basically a regional extension of Atlantic species. As the extreme environmental conditions of low temperature, low salinity and long periods of darkness intensify towards the western and northern parts of the Canadian Arctic, there is a marked reduction in the number of species. The protective cover of sea ice, together with the seasonal development of a low salinity layer from ice melt, hinders mixing between water layers, and nutrient replenishment is apparently a critical problem. Communities are generally small and isolated largely because of substrate limitations. A population may be extensive and dense, but this is attributed to the small number of species and the relative ineffectiveness of most of these in competing for the available space. Following seasonal ice melt, the intertidal habitat in colder regions remains unsuitable for algal growth, because of its exposure to a combination of adverse climatic and oceanographic conditions. The decreasing diversity of species, as the physical conditions become more adverse, together with the nearly complete absence of endemics, indicate a low level of adaptation, and the arctic communities are judged to be ecologically immature.
Although television pictures from Earth satellites have been used for over ten years to detect major sea ice features, direct photo-interpretation methods have been supplemented with a fully-automated technique employing Composite Minimum Brightness (CMB) charts. Lack of on-board calibration has prevented quantitative use of the CMB method. In a newly-developed procedure the satellite brightness measurements taken over selected areas are used for external calibration. The calibrated data were used to study sea ice conditions in the North American Arctic. Characteristic brightness levels were found corresponding to the following: 1) compact or very close pack, snow covered; 2) compact or very close pack, without snow but with little or no puddling; 3) very close to close pack with much puddling; 4) open pack, generally with much puddling and rotten ice; 5) very open pack or ice-free conditions.
Ninety-three species of vascular plants are recorded from a 16 sq. mile coastal lowland on the northern coast of Devon Island, Northwest Territories. The following taxa are apparently new records for Devon Island: Cystopteris fragilis, Woodsia alpina, Equisetum variegatum, Poa alpigena, Carex amblyorhyncha, Draba oblongata, Saxifraga tenuis, Epilobium arcticum, Hippuris vulgaris, Pedicularis lanata, Puccinellia vaginata var. paradoxa. These additions bring the total known flora of Devon Island to 115 species. The Truelove flora is part of the High Arctic biogeographic element of the Canadian Arctic Archipelago. However, a distinct element of species of more southerly distribution is present probably due to the moderating influence of the lowland environment.
Opinions with respect to whether it is in the public interest to construct roads into wilderness areas of Alaska and the Canadian territories are varied. ... Much time has been devoted to impact studies of new or improved highways on urban and rural areas, and much energy has been devoted to studies of the impact of new or improved highways on commercial, residential or recreational developments. ... In Alaska and the Canadian Territories today the stage of development of the countryside at the time of highway construction compares in many ways to that of eastern North America in the early 1800s. ... Concern for the environment through which a highway passed was undreamed of in the early 1800s, and even 150 years later few actually worry about highway impact. ... All authorities agree that changes in the visible landscape do begin with the construction of a highway through a wilderness area of the Arctic or Subarctic. A preponderance of opinion favours the view that the benefits to be derived from new highways do outweigh the undesirable side effects, and plans for future highway construction in Alaska, the Yukon, and Northwest Territories tend to indicate this to be the official view as well. The background of conflicting opinions, claims, and counter-claims which have been building to the present intensity for several years prompted this study. ... During the spring and summer of 1972 approximately 8,000 miles of Alaskan and Yukon Territorial highways were travelled in an effort to gain first-hand knowledge of present conditions along the corridors of highways which had been built through wilderness areas during the past thirty years .... Although the investigation of these Canadian and Alaskan highways was in the nature of a reconnaissance and any conclusions must certainly be validated by further study, it would appear that the construction of a new highway through a wilderness area starts an irreversible series of more or less predictable events. First come the surveyors and the contractors who plan and build the highway. Then there are the hunters and fishermen who want to get in and get theirs before they and others "spoil" the country. On the heels of the sportsmen come guides, outfitters, small enterprises which provide gasoline, tire repairs, groceries, and possibly food and lodging. These small businesses may expand and improve the quality of their services, or others with more capital and experience may provide competition which forces the first comers out of business. ... we must recognize that highways will be built through wilderness areas, and that they can be built in such a way that the changes in the wilderness environment will be acceptable. The greatest environmental problems are created by those who will use the highways for purposes of access and exploitation of a heretofore inaccessible wilderness. It is essential that there be a comprehensive land use plan which would allocate appropriate areas for all activities and allocate the locations for all installations, services and recreational areas in such a way that incompatible activities would not be in too close proximity. Thus by anticipation of conflict and the use of land allocations or zoning it would appear that optimum land utilization can be achieved and the wilderness character of the area preserved.
During February 1972, scientific personnel operating from the Louis S. St. Laurent obtained the first winter oceanographic temperature and salinity data from Baffin Bay. Six oceanographic stations were occupied: one in central Baffin Bay; a second in eastern Baffin Bay southeast of the first; and a cross-section of 4 stations in southern Davis Strait .... The temperature and salinity data were obtained using discrete samples from Knudsen bottles, equipped with deep-sea reversing thermometers, and an in situ recording salinity/temperature/depth unit (STD). Temperatures and salinities determined from the discrete water samples were used to calibrate the STD and correct it for drift, while the STD was used to detect fine structure in the vertical distributions of temperature and salinity. ... The temperatures presented ... were those obtained from the reversing thermometers. ... they are presented here in comparison with summer data from the same region .... While it is not possible to draw quantitative conclusions from the small amount of available information, it appears that the deep vertical distributions of temperature and salinity in central and southeastern Baffin Bay and Davis Strait may not undergo significant seasonal variation. Observed near-surface variations may be accounted for qualitatively by a combination of winter cooling, freezing and convective mixing and summer meltwater addition. The apparent constancy of flow through Davis Strait is of particular interest. It has been demonstrated that for sufficient heat to be present in the water column for prevention of ice formation in the open lead in northern Baffin Bay known as the North Water, northerly flow of warm water (>0°C) would have to be greater than observed during the summer months. That this does not appear to be the case strengthens the hypothesis... that the open water is due to a southward advection of ice by winds and currents rather than by heat from the water column preventing formation of the ice.
On completion of observations in Nares Strait from the CCGS Louis S. St. Laurent during August 1971, the opportunity arose to make a quick reconnaissance in Makinson Inlet. This inlet ... provides a sea-level passage from the North Water area through the coast range of eastern Ellesmere Island .... However, nothing was known of its bathymetry or oceanography except for a line of soundings run by CCGS Labrador in 1966. Since all of the oceanographic party with the exception of the author had already left the ship, the investigation could only be superficial, but ... a few preliminary observations were made. ... On the way up the inlet a line of soundings was maintained and a series of shoreline photographs was taken. ... On the way down the inlet, 4 oceanographic stations were occupied and Knudsen bottle samples were taken for temperature, salinity and dissolved oxygen content. Bathythermograph slides were also obtained. Since there is no sill in the main section of the inlet the classic fiord structure cannot develop and the results obtained indicate that the inlet, from the fork seaward, is from the oceanographic point of view merely a section of northern Baffin Bay. The T-S curves ... show that there are two main layers, one below 300 m and a second between 100 and 200 m These layers match those in northern Baffin Bay .... Above these in the upper 75 m or so the effects of melt water are apparent. Since the fresh water input is distributed down the full length of the inlet, the salinity at 10 m actually decreases to seaward by 0.98 per mil between Stations 1 and 4, but the gradient reverses when the salinity is integrated over the upper 75 m .... It must be stressed that the melt water effect is very short lived with the bulk of the run-off coming in a period-as short as 2 weeks. The dissolved oxygen content remains high (>6 ml/L) right to the bottom, another indication of identity with the water in Baffin Bay. A great deal of work is still needed to provide the comprehensive view of the oceanography of this inlet which is necessary before any regular use by shipping. The details of water exchange with Baffin Bay, the amount and duration of fresh water input from the numerous glaciers, the existence of a sill in the entrance to the North West Arm and the possibility of stagnant water behind it are some of the obvious lines of investigation in the future. ...
For several years two male polar bears have been studied by long-life implanted physiological radio capsules at the Naval Arctic Research Laboratory, at Point Barrow. One of the siblings has consistently been larger than the other. A regular measurement has been the resting heart rate; for this we used the lowest heart rate obtained during night-time sleep. Night-time sleep is used because different heart rate levels are obtained during day-time sleep and night-time sleep. The two bears, during the continuous light of the summer, sleep regularly from about 11 PM until 9:00 AM; occasionally short bouts of sleep occur around early afternoon. Sleeping heart rates have been obtained throughout the lifetime of these two individuals. For example, during the summer of 1971, the larger polar bear, Irish (310 kg), had mean resting heart rates of 54 ±2 SD b/m (N=12); in 1972 at 332 kg his rate was 48 ±5 SD b/m (N=12); the smaller bear in 1971, at 286 kg, had a lower sleeping heart rate (50 ±5 SD b/m). ... A technique for demonstrating bradycardia (rapid slowing of heartbeat) in marine mammals was developed by Irving and Scholander, namely instrumenting the animal and training it to place its head under water. We decided to try this technique with the larger of the polar bears (Irish). The bear was separated from its companion, deprived of food and water overnight, and then recorded during three routine situations: 1) during high activity time; 2) during the filling of the water tub (approximately 300 litres) and 3) during feeding time. Heart rates were taken by the stopwatch every 15 seconds. ... Head immersion and diving bradycardia were evident for periods lasting up to 2 minutes; during that time the animal appeared to be searching for food at the bottom of the tub. Although diving bradycardia was evident (rate reduced 10 per cent to 72 b/m), it is apparent that there was much more bradycardia during the period of eating (reduced 20 per cent to 60 b/m). This slow rate during eating was remarkably close to the sleeping heart rate. One might have expected the heart rate to go up during the excitement of feeding. Also, competition for the food was not entirely lacking; the companion polar bear in the adjoining cage was constantly reaching through the bars as it attempted to obtain some of the food. One might have expected this activity to increase the excitement. We have found no other reference to bradycardia during feeding.
Fragments of vertebrate fossils are found in beds of the Shublik Formation, which blanketed most of northern Alaska during Triassic time. Although articulated remains are uncommon, one partial skeleton was discovered in 1950 during exploration of Naval Petroleum Reserve No. 4. ... This note calls attention to the existence of the skeleton and reports on what has been observed of the vertebrate remains. Figs. 1 and 2 locate the site (68°37'15" N, 157°35' W) on Cutaway Creek (Howard Pass 1:250,000-scale quadrangle) in the geologically disturbed zone of the Brooks Range foothills. It is about 200 miles south of Point Barrow and 35 miles northwest of Howard Pass. Fig. 3 is a photograph of the actual bedding-plane exposure. Most of one side of the rib case is exposed, and some limb structures seem preserved. The exposed parts indicate a skeleton more than 5 feet long. Bone fragments are common in the fine talus weathering off the outcrop. Although no invertebrate fossils were seen on the surfaces of beds containing the skeleton, they are abundant in correlative beds; detailed examination of this or nearby exposures should yield pelecypods that will fix the biostratigraphic level of the vertebrate remains. Some features of the Late Triassic environment can be assessed. A sea of remarkably persistent character extended beyond the length of the present Brooks Range and probably more than twice the width of the present Arctic Slope. A shoreline existed near the present northeast coast of Alaska, but coarse detritus was not carried far southward. The bottom elsewhere was below wave base, and the sediment that settled onto it formed thin deposits, first of anaerobic chert, shale and limestone, then aerobic lithographic limestone. Pectens ... are abundant .... The thin chert beds surrounding the skeleton are correlative with beds elsewhere that contain Halabia of Karnian or early Norian age .... The skeleton is older than 200 million years as shown by K/Ar age determinations on minerals in diabase sills that intrude the Shublik Formation about 20 miles to the east .... Vertebrate fragments previously collected from the Shublik have been identified as follows: from this locality and from limestone near Hardway Creek (68°38'5" N, 156°51' W) about 20 miles to the east - vertebra of a possible ichthyosaur and teeth of a probable Mixasaurus ...; in limestone, chert, and shale on Kiligwa River (68°43'45" N, 158 °26' W) about 25 miles to the northwest - probable caudal vertebra of an ichthyosaur ...; and in limestone at the west end of the Sadlerochit Mountains (69°35'15" N, 145°55'5" W), northeastern Brooks Ranges - vertebral, costal, and jaw fragments of either the Shastasauridae or Ichthyosauridae ichthyosaur family .... Helicopters offer the only practical access to the site, for the nearest lake on which a float plane can land is more than 10 miles away. Transportation for preliminary inspection could probably be arranged with any geologic field party working within a hundred miles of the locality. Collection of the skeleton would require that an outfit be landed near the outcrop by ski plane in the spring and retrieved during the fall or winter. We cannot judge the quality or significance of the skeleton but feel that it should be examined by a vertebrate paleontologist as it could yield valuable information on life in the seas during Triassic time at a present arctic latitude.
From April 1972 through the 1973 field season, the Arctic Institute's research base on the northeast coast of Devon Island (75°40'N, 84°40'W) will be the seat of operations for scores of investigators and their field assistants. The major research program continues to be a large integrated tundra ecosystem study sponsored by the Canadian International Biological Program (IBP). The Base Camp is also being used by groups of researchers from the Canadian Wildlife Survey, and from the Polar Continental Shelf Project. The two AINA-sponsored projects are summarized below. ... During the summer of 1972, and the winter of 1972-73, the camp was used as a communications centre, and for providing other assistance to research stations established on Coburg Island and on the Carey Islands (Greenland) which are part of the Institute's North Water Project. ...  ECOLOGICAL STUDIES OF SEDGE-DOMINATED MEADOW TUNDRA. During the 1972 field season studies were continued on the ecology of sedge-dominated meadows. ... Studies of rhizome behaviour were continued. Complete systems were excavated and collected at five locations. Rhizome growth was monitored on selected individual plants. ... Population characteristics of sedges invading small ponds and drained lake systems were further investigated. Three-and-a-half weeks were spent at the National Museum of Natural History camp on Bathurst Island. ... six sedge meadows were selected and analysed for comparison with the Devon Island meadows. Five permanent plots were also established and mapped and populations of Carex stans collected for both seed and morphological measurements. A project to investigate the revegetation of vehicle-disturbed sedge meadows with native Carex species was also initiated. ... Analysis of plantings of Carex stans as well as natural revegetation in some blocks will be monitored in following seasons. ...  VEGETATION STUDIES ON THE INTERIOR PLATEAU. ... A 2.4 km transect was placed east from the Plateau margin to the interior. The transect crossed a number of habitats, including solifluction terraces, stripes and sorted nets. Four maximum-minimum thermometer enclosures and two hygrothermograph stations were set out to determine microclimatic variations along the line. Forty 25 m² quadrats were placed at 80 m intervals along the transect for vegetation analysis. At each plot, the percentage cover of rock, soil, vascular plants and bryophytes was calculated; species composition was determined and voucher specimens from each quadrat were collected. Lichen specimens were also collected for later taxonomic determinations in the laboratory. Surface soil samples from each plot were collected for mechanical and chemical analysis. ... At 5 points along the transect, regular sampling of soil at 0 and 15 cm was undertaken to determine a curve of seasonal soil moisture. These values will be compared with concurrent samples taken in nonsorted circles on the Lowland. In addition to the 40 systematic plots, 5 additional sites were also ana1ysed. ... Comparisons with the transect data should indicate if the visual homogeneity of the vegetation on the Plateau is constant over a large area. A high density bryophyte community at the head of a drainage system and one solifluction terrace characterized by Alopecurus were also analysed. These sites were unusual in that they both had vegetation cover values greater than 40 per cent. Other plots on the Plateau had values of 1 to 4 per cent. ...