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Potentiation of ecological factors on the disruption of thyroid hormones by organo-halogenated contaminants in female polar bears (Ursus maritimus) from the Barents Sea.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-11)
As apex predators, polar bears (Ursus maritimus) are among the most heavily polluted organisms in the Arctic. In addition to this anthropogenic stressor, climate warming has been shown to negatively affect their body condition, reproductive output and survival. Among potential underlying physiological mechanisms, thyroid hormones (THs), which control thermoregulation, metabolism and reproduction, ...
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 ...
An Arctic predator–prey system in flux: climate change impacts on coastal space use by polar bears and ringed seals
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-17)
<p>1. Climate change is impacting different species at different rates, leading to alterations in biological interactions with ramifications for wider ecosystem functioning. Understanding these alterations can help improve predictive capacity and inform management efforts designed to mitigate against negative impacts.</p>
<p>2. We investigated how the movement and space use patterns of polar bears ...
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 ...
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, ...
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 ...
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 ...
Modeling the demography of species providing extended parental care: A capture–recapture multievent model with a case study on polar bears (Ursus maritimus)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-10)
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<li>In species providing extended parental care, one or both parents care for altricial young over a period including more than one breeding season. We expect large parental investment and long-term dependency within family units to cause high variability in life trajectories among individuals with complex consequences at the population level. So far, models for estimating demographic ...
Marine mammal hotspots in the Greenland and Barents Seas
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-04)
Environmental change and increasing
levels of human activity are threats to marine mam-
mals in the Arctic. Identifying marine mammal hot -
spots and areas of high species richness are essential
to help guide management and conservation efforts.
Herein, space use based on biotelemetric tracking
devices deployed on 13 species (ringed seal <i>Pusa
hispida</i>, bearded seal <i>Erignathus ...
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, ...