ALBERT

Notes: Aerial strip surveys of polar bears in the Barents Sea were performed by helicopter in winter 1987. The number of bears within 100 m on each side of the helicopter was counted. A total of 263.6 km2 was surveyed and 21 bears were counted. Most of the bears were found in the southern part of the area, which indicates that the southwestern ice edge area in the Barents Sea is a very important winter habitat for polar bears.

Notes: Abstract: The paper describes the use of the drugs Zoletil® and etorphine for the immobilization of walrus (Odobenus rosmarus rosmarus) for attachment of satellite telemetry equipment. Three animals weighing approximately 1,500 kg each were injected intramuscularly with Zoletil® at a dose between 1.4 and 2.2 mg/kg. One walrus died while the two others were adequately restrained. The induction time was between 14 and 29 minutes and the effect lasted for 75-220 min.Thirty-eight animals of weight 900-1,500 kg were darted intramuscularly with etorphine at a dose between 3.3 and 8 mg/kg. Thirty-six were immobilized although one died later. The induction time for etorphine was two to ten minutes. The action of this drug was terminated with an injection of the antidote di-prenorphine.The use of etorphine was accompanied by convulsive movements and apnoea while Zoletil® produced a gradual and smooth entry into and withdrawal from immobilization.

Notes: Multivariate statistical analyses of 18 morphometric characters were performed in order to evaluate potential heterogeneity between predefined minke whale stock unit areas in the North Atlantic (West Greenland, Central, and Northeastern stocks). Results from principal component analyses suggested that the data cannot be regarded as random samples drawn from one uniform distribution. The overlap between groups was too substantial, however, to allow a firm conclusion concerning the question of isolated breeding stocks versus a large common breeding pool.

Notes: The present analysis confirms that the northernmost record of common seals (Phoca vitulina) in the world is at Svalbard nearly at 81°N. The population at Prins Karls Forland, Svalbard, is about 900 km away from any other population of common seals and may be termed insular. External and cranial characters of three common seals caught at Prins Karls Forland, and one common seal caught at Rossøya, all at Svalbard, are described. The only three available skins from Svalbard common seals are of a light phase color type. The skulls are characterized by a narrow interorbital width and a posterior extent of the palato-vomerine septum which is greater than that described for Atlantic common seals. A detailed description of the morphology of Atlantic common seals is highly needed.

Notes: Abstract Hair samples of 15 adult male Atlantic walruses (Odobenus rosmarus rosmarus) collected from anaesthetized individuals at Svalbard, Norway, were analysed for cadmium and total mercury. The mean level of cadmium was 0.860 ± 0.321 μg/g dry weight (median = 0.811, range = 0.349–1.51 μg/g dry weight) and the mean level of mercury was 0.235 ± 0.100 μg/g dry weight (median = 0.251, range = 0.121–0.424 μg/g dry weight). Levels of cadmium and mercury in hair of walruses from other areas are not known. Both cadmium and mercury levels in hair of walruses from Svalbard are relatively low compared to the levels found in the hair of other marine mammal species. It has been documented from a number of marine species, including marine mammals such as ringed seals and polar bears, that both cadmium and mercury levels at Svalbard are lower than in other areas. It is uncertain as to what degree levels in hair reflect levels in internal organs in walruses. In rare and highly endangered species or populations tissue samples can be difficult to collect. In walruses, it is possible to collect hair from anaesthetized individuals or at the haul-out sites during moult, to monitor heavy metal levels of the population.

Notes: Abstract Polar bears (Ursus maritimus) are believed to be obligate predators on marine mammals, and particularly, on two species of seals. This paper reports on observations of polar bears preying (n=7) and scavenging (n=6) on Svalbard reindeer (Rangifer tarandus platyrhyncus). Similar to their closest evolutionary ancestor, the brown bear (U. arctos), polar bears are opportunistic and will prey on ungulates. Reindeer are likely of minor importance to the foraging ecology of polar bears in Svalbard, but the observations suggest behavioural plasticity in response to a novel prey item.

Notes: Abstract Skin and blubber samples of ten adult male Pacific walruses (Odobenus rosmarus divergens) from Alaska were used to investigate the relationship between organochlorine (OC) levels in skin and blubber of individuals. For analyses we selected 11 components that were quantified in the blubber of all individuals: hexachlorocyclohexanes (αHCH and βHCH), the DDT (dichlorodiphenyltrichloroethane) metabolite p,p′DDE, oxychlordane, and 7 individual PCB congeners, 28, 99, 105, 118, 138, 153 and 180. The correlation between the levels in the two types of tissues was significant and the relation was isometric for all components. The regression coefficient between levels in blubber (dependent variable) and levels in skin (independent variable) was different from 1 for only four of the components. The mean levels in the two types of tissues were significantly different for 3 of the 11 chemical components (βHCH, oxychlordane, and PCB28). Although this analysis is based on only ten individuals, we propose that skin samples taken by biopsy darts can be used to monitor OC levels in walruses. In August 1993 skin biopsies were collected from 25 adult male Atlantic walruses (O. r. rosmarus) at haul-out sites in southeastern Svalbard in the Norwegian Arctic and from 28 walruses of different sex and age at haul-out sites at Franz Josef Land in the Russian Arctic. The mean levels of OCs were 2–10 times higher at Svalbard than at Franz Josef Land. The dominant OC component was PCB153 in both areas. A principal component analysis detected differences between areas in OC levels but not in patterns. Since the Franz Josef Land samples were mainly taken from females and young individuals and the Svalbard samples were taken largely from adult males, we believe the differences in tissue OC levels observed from these areas can be explained by differences in sex and age of the walrus sampled. Comparable organochlorine levels in skin samples from walruses from other areas are not available. However, compared to the corresponding OC levels found in walrus blubber in other areas, the OC levels from Svalbard and Franz Josef Land are higher. The high levels of OCs in walruses from Svalbard and Franz Josef Land may be a combined effect of high pollution level in the environment and seal-eating habits. In the present study we show that it is possible to use skin biopsies taken by a non-destructive method to assess OC levels in walruses.