31 research outputs found

    The use of Global Positioning Systems to record distances in a helicopter line-transect survey

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    Methods that allow unbiased estimation of animal abundance are increasingly demanded in management and conservation. The use of these methods should respect their assumptions. The need for accurate distance measurements in distance-sampling surveys is stressed. Here we present 2 alternative methods for measuring distance from a line to an object during helicopter surveys: 1) using a Global Positioning System (GPS) unit, with distances measured using appropriate software; and 2) recording declination angles and altitudes, using basic trigonometry to obtain the appropriate distances. These are compared to distances measured by a laser rangefinder (assumed to be true distances). The effect of the different errors on estimated densities is assessed by simulation. The GPS method appeared to be very accurate, while a potential downward bias in estimated density could be present if the inclinometer method is used. We discuss the implication for wildlife studies of using different measurement methods leading to different errors.</p

    Marine mammal hotspots across the circumpolar Arctic

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    Aim: Identify hotspots and areas of high species richness for Arctic marine mammals. Location: Circumpolar Arctic. Methods: A total of 2115 biologging devices were deployed on marine mammals from 13 species in the Arctic from 2005 to 2019. Getis-Ord Gi* hotspots were calculated based on the number of individuals in grid cells for each species and for phyloge-netic groups (nine pinnipeds, three cetaceans, all species) and areas with high spe-cies richness were identified for summer (Jun-Nov), winter (Dec-May) and the entire year. Seasonal habitat differences among species’ hotspots were investigated using Principal Component Analysis. Results: Hotspots and areas with high species richness occurred within the Arctic continental-shelf seas and within the marginal ice zone, particularly in the “Arctic gateways” of the north Atlantic and Pacific oceans. Summer hotspots were generally found further north than winter hotspots, but there were exceptions to this pattern, including bowhead whales in the Greenland-Barents Seas and species with coastal distributions in Svalbard, Norway and East Greenland. Areas with high species rich-ness generally overlapped high-density hotspots. Large regional and seasonal dif-ferences in habitat features of hotspots were found among species but also within species from different regions. Gap analysis (discrepancy between hotspots and IUCN ranges) identified species and regions where more research is required. Main conclusions: This study identified important areas (and habitat types) for Arctic marine mammals using available biotelemetry data. The results herein serve as a benchmark to measure future distributional shifts. Expanded monitoring and teleme-try studies are needed on Arctic species to understand the impacts of climate change and concomitant ecosystem changes (synergistic effects of multiple stressors). While efforts should be made to fill knowledge gaps, including regional gaps and more com-plete sex and age coverage, hotspots identified herein can inform management ef-forts to mitigate the impacts of human activities and ecological changes, including creation of protected areas

    DISTRIBUTION AND MIGRATION OF POLAR BEARS, PACIFIC WALRUSES AND GRAY WHALES DEPENDING ON ICE CONDITIONS IN THE RUSSIAN ARCTIC (17th Symposium on Polar Biology)

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    This report presents a review of available data concerning the influence of ice cover on distribution, density and migration of three species of marine mammals inhabiting the Russian Arctic. Association of marine mammals with ice cover is as follows: (1) the polar bear is distributed in ice zone in the whole year, (2) the walrus is associated with the ice zone only in summer, and (3) the gray whale inhabits the southern area of the ice zone

    The ringed seal (<i>Phoca hispida</i>) in the western Russian Arctic

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    This paper presents a review of available published and unpublished material on the ringed seal (Phoca hispida) in the western part of the Russian Arctic, including the White, Barents and Kara seas. The purpose of the review is to discuss the status of ringed seal stocks in relation to their primary habitat, the history of sealing, and a recent harvest of the species in the region. The known primary breeding habitats for this species are in the White Sea, the south-western part of the Barents Sea, and in the coastal waters of the Kara Sea, which are seasonally covered by shore-fast ice. The main sealing sites are situated in the same areas. Female ringed seals become mature by the age of 6, and males by the age of 7. In March-April a female gives birth to one pup in a breeding lair constructed in the shore-fast ice. The most important prey species for ringed seals in the western sector of the Russian Arctic are pelagic fish and crustaceans. The maximum annual sealing level for the region was registered in the first 70 years of the 20th century: the White Sea maximum (8,912 animals) was registered in 1912; the Barents Sea maximum (13,517 animals) was registered in 1962; the Kara Sea maximum (13,200 animals) was registered in 1933. Since the 1970s, the number of seals harvested has decreased considerably. There are no data available for the number of seals harvested annually by local residents for their subsistence

    Belugas (<i>Delphinapterus leucas</i>) of the Barents, Kara and Laptev seas

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    This paper reviews published information on the white whale or beluga (Delphinapterus leucas) inhabiting the Barents, Kara and Laptev seas. Some data obtained during multi-year aerial reconnaissance of sea ice in the Russian Arctic are also included. Ice conditions, considered one of the major factors affecting distribution of belugas, are described. The number of belugas inhabiting the Russian Arctic is unknown. Based on analysis of published and unpublished information we believe that the primary summer habitats of belugas in the Western Russian Arctic lie in the area of Frants-Josef Land, in the Kara Sea and in the western Laptev Sea. Apparently most belugas winter in the Barents Sea. Although it has been suggested that a considerable number of animals winter in the Kara Sea, there is no direct evidence for this. Apparent migrations of animals are regularly observed at several sites: the straits of the Novaya Zemlya Archipelago, the waters north of the archipelago, and Vilkitskiy Strait between the Kara and Laptev seas. Calving and mating take place in summer, and the beluga mother feeds a calf for at least a year. Females mature earlier than males, and about 30% of mature females in a population are barren. Sex ratio is apparently close to 1:1. The diet of the beluga in the region includes fish and crustaceans and shows considerable spatial and temporal variations. However, polar cod (Boreogadus saida) is the main prey most of the year, and whitefish (Coregonidae) contribute in coastal waters in summer. Usually belugas form groups of up to 10 related individuals of different ages, while large aggregations are common during seasonal migrations or in areas with abundant and easily available food. Beluga whaling in Russia has a history of several centuries. The highest catches were taken in the 1950s and 1960s, when about 1,500 animals were caught annually in the Western Russian Arctic. In the 1990s, few belugas were harvested in the Russian Arctic. In 1999 commercial whaling of belugas in Russia was banned. Belugas can be caught only for research, cultural and educational purposes and for the subsistence needs of local people. With the absence of significant whaling, anthropogenic pollution seems to be the major threat for the species

    Serosurvey of Selected Zoonotic Pathogens in Polar Bears (Ursus maritimus Phipps, 1774) in the Russian Arctic

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    Antibodies to several pathogens were detected in the serum samples of nine polar bears (Ursus maritimus, Phipps, 1774) from areas of the Russian Arctic. Plasma was studied for antibodies to sixteen infectious and parasitic diseases using indirect Protein-A ELISA. It is known that when using ELISA, the interaction of antibodies with a heterologous antigen is possible due to immunological crossings between antigens. We investigated the plasma for the presence of antibodies to the major pathogens and for the presence of antibodies to pathogens, for which the cross-immunological reactions to these pathogens are described. For example, antibodies to the pathogens of opisthorchiasis, clonorchiasis, and ascariasis were found simultaneously in four polar bears. Antibodies to both anisakidosis and trichinellosis pathogens were found in six animals. The data obtained may also indicate a joint invasion by these pathogens. Unfortunately, due to the small number of animals sampled, it is impossible to carry out statistical processing of the data

    Serosurvey of Selected Zoonotic Pathogens in Polar Bears (<i>Ursus maritimus</i> Phipps, 1774) in the Russian Arctic

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    Antibodies to several pathogens were detected in the serum samples of nine polar bears (Ursus maritimus, Phipps, 1774) from areas of the Russian Arctic. Plasma was studied for antibodies to sixteen infectious and parasitic diseases using indirect Protein-A ELISA. It is known that when using ELISA, the interaction of antibodies with a heterologous antigen is possible due to immunological crossings between antigens. We investigated the plasma for the presence of antibodies to the major pathogens and for the presence of antibodies to pathogens, for which the cross-immunological reactions to these pathogens are described. For example, antibodies to the pathogens of opisthorchiasis, clonorchiasis, and ascariasis were found simultaneously in four polar bears. Antibodies to both anisakidosis and trichinellosis pathogens were found in six animals. The data obtained may also indicate a joint invasion by these pathogens. Unfortunately, due to the small number of animals sampled, it is impossible to carry out statistical processing of the data
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