English
norskBlar i forfatter "Andersen, Magnus"
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Bacterial diversity in faeces from polar bear (Ursus maritimus) in Arctic Svalbard
(Journal article; Tidsskriftartikkel; Peer reviewed, 2010)Background Polar bears (Ursus maritimus) are major predators in the Arctic marine ecosystem, feeding mainly on seals, and living closely associated with sea ice. Little is known of their gut microbial ecology and the main purpose of this study was to investigate the microbial diversity in faeces of polar bears in Svalbard, Norway (74-81 degrees N, 10-33 degrees E). In addition the level of blaTEM ... -
Choose your poison – Space-use strategy influences pollutant exposure in Barents Sea polar bears
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-24)Variation in space-use is common within mammal populations. In polar bears, Ursus maritimus, some individuals follow the sea ice (offshore bears) whereas others remain nearshore yearlong (coastal bears). We studied pollutant exposure in relation to space-use patterns (offshore vs coastal) in adult female polar bears from the Barents Sea equipped with satellite collars (2000–2014, n = 152). First, ... -
Diet and metabolic state are the main factors determining concentrations of perfluoroalkyl substances in female polar bears from Svalbard
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-03)Perfluoroalkyl substances (PFASs) have been detected in organisms worldwide, including Polar Regions. The polar bear (Ursus maritimus), the top predator of Arctic marine ecosystems, accumulates high concentrations of PFASs, which may be harmful to their health. The aim of this study was to investigate which factors (habitat quality, season, year, diet, metabolic state [i.e. feeding/fasting], breeding ... -
Geographical area and life history traits influence diet in an Arctic marine predator
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-19)Global changes are thought to affect most Arctic species, yet some populations are more at risk. Today, the Barents Sea ecoregion is suffering the strongest sea ice retreat ever measured; and these changes are suspected to modify food access and thus diet of several species. Biochemical diet tracers enable investigation of diet in species such as polar bears (Ursus maritimus). We examined ... -
Pelagic vs coastal - Key drivers of pollutant levels in Barents Sea polar bears with contrasted space-use strategies
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-11)In the Barents Sea, pelagic and coastal polar bears are facing various ecological challenges that may explain the difference in their pollutant levels. We measured polychlorinated biphenyls, organochlorine pesticides, polybrominated diphenyl ethers in fat, and perfluoroalkyl substances in plasma in pelagic and coastal adult female polar bears with similar body condition. We studied polar bear feeding ... -
Polar bears (Ursus maritimus) in the Barents Sea area : population biology and linkages to sea ice change, human disturbance and pollution
(Doctoral thesis; Doktorgradsavhandling, 2013-03-16)Polar bears in the Barents Sea population have been protected from hunting in Russia since 1956 and following the signing of the international Polar Bear Agreement in 1973 in Norway. This thesis seeks to summarise current knowledge on key population biology issues four decades after the Norwegian protection and almost six after the Russian. Further, it discusses threats that have developed in the ... -
A risk assessment review of mercury exposure in Arctic marine and terrestrial mammals
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-16)There has been a considerable number of reports on Hg concentrations in Arctic mammals since the last Arctic Monitoring and Assessment Programme (AMAP) effort to review biological effects of the exposure to mercury (Hg) in Arctic biota in 2010 and 2018. Here, we provide an update on the state of the knowledge of health risk associated with Hg concentrations in Arctic marine and terrestrial mammal ... -
Sea ice reduction drives genetic differentiation among Barents Sea polar bears
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-08)Loss of Arctic sea ice owing to climate change is predicted to reduce both genetic diversity and gene flow in ice-dependent species, with potentially negative consequences for their long-term viability. Here, we tested for the population-genetic impacts of reduced sea ice cover on the polar bear (<i>Ursus maritimus</i>) sampled across two decades (1995–2016) from the Svalbard Archipelago, Norway, ... -
Selvfortapelse
(Master thesis; Mastergradsoppgave, 2013-05-29)Oppgaven tar for seg selvfortapelse som fenomen, dens mulighetsbetingelser og hvilke forhold som må ligge til rette for å unngå å bli oppslukt i fellesskapet. Den teoretiske basis ligger hovedsaklig hos Kierkegaard, Sartre og Heidegger. -
Space-use strategy affects energy requirements in Barents Sea polar bears
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-02)Polar bears Ursus maritimus are currently facing rapid environmental changes with loss of sea ice and shifts in their prey distribution. Two distinct ecotypes exist in the Barents Sea, where sea ice is decreasing at the highest rate in the Arctic. Coastal bears remain within the Archipelago of Svalbard year-round, whereas offshore bears follow the marginal ice zone (MIZ). We explored these 2 ecotypes’ ... -
Spatial variation in mercury concentrations in polar bear (Ursus maritimus) hair from the Norwegian and Russian Arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-02)We examined spatial variation in total mercury (THg) concentrations in 100 hair samples collected between 2008 and 2016 from 87 polar bears (Ursus maritimus) from the Norwegian (Svalbard Archipelago, western Barents Sea) and Russian Arctic (Kara Sea, Laptev Sea, and Chukchi Sea). We used latitude and longitude of home range centroid for the Norwegian bears and capture position for the Russian bears ... -
Temporal trends of persistent organic pollutants in Barents Sea polar bears (Ursus maritimus) in relation to changes in feeding habits and body condition
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-14)Temporal trends of persistent organic pollutants (POPs: PCBs, OH-PCBs, <i>p,p′</i>-DDE, HCB, β-HCH, oxychlordane, BDE-47, and 153) in relation to changes in feeding habits and body condition in adult female polar bears (<i>Ursus maritimus</i>) from the Barents Sea subpopulation were examined over 20 years (1997–2017). All 306 samples were collected in the spring (April). Both stable isotope values ...
