BearHealth                    Link to Norwegian website

Polar Bear (Ursus maritimus) Circumpolar Health Assessment in Relation to Toxicants and Climate Changing

At present human activities have an impact on almost all ecosystems, even those in the Arctic. The impact of human activity on biodiversity and ecosystem functioning is not caused by only one single anthropogenic (man-made) factor, but is the results of a combination several different factors (anthropogenic stressors). Climate change and exposure to long-range pollutants are two of the most significant human caused threats to Polar bears.

In BearHealth we aim at focusing on the effects of toxicant exposure and climate change on the health of polar bears. As a species, the polar bear appeared 200 000 years ago during the Pleistocene. Since then, there have been large variations in the global climate, including a warm period approximately 125 000 years ago. Thus, since  the  Polar bear still exists, it has obviously able to adapt to climate changes in previous times. Today, the Polar bear is also exposed to other anthropogenic stressors, such as toxic man-made pollutants. Some of these toxicants are persistent against degradation, and are biomagnified in food chains. Because the Polar bear is the apex predator in the Arctic, levels of some persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCB), can reach very high levels. Associations between pollutant levels and physiological factors, such as hormone and vitamin status and immune function, have been reported in Polar bears. Our concern is that alterations in the physiological homeostasis of polar bears caused by toxicants or endocrine disrupting chemicals may significantly abrupt the physiological (and evolutionary) adaptations of the Polar bear to a warmer climate in the Arctic. Thus, in combination, a warmer temperature in the Arctic and high levels of toxicants and endocrine disrupters may cause the extinction of the Polar bear.


17 March 2007: R/V Lance, which is the Norwegian Polar Institute's reseach vessel, left from Tromsø and is heading for East-Greenland and Svalbard. The researchers will be live-catching polar bears to collect blood samples and to attach satellite transmitters to females. Blood samples will be analyzed for pollutant levels and hormones, and satellite transmitters will give information on their dispersal behavior.

18 May 2007: BBC News report from BearHealth. The news report is based on a news report presented in the Norwegian Broadcasting (NRK). The video shots from the expedition are made by PhD fellow Jenny Bytingsvik, NTNU.

22 May 2007: MSc Jenny Bytingsvik is employed as a PhD fellow on BearHealth. She participated on the sampling expedition with R/V Lance in March and April. Almost 80 polar bears were caught, tagged and examined during the expedition. Jenny got blood samples from about 35 polar bears, and analysed the blood for a range of clinical variables while she was aboard the ship. The samples are now at NTNU awaiting further analyses of contaminant levels as well as analysis of hormone and vitamin levels. In addition, our Danish colleagues. A project meeting was held last week, and one of our goals will be to study changes in contaminant burden and health status in polar bears since the late 1990's. Taking the climate changes which have occurred in the Arctic during the past decade into account, we hope that this will give us good information on the effects of climate change on pollutant patterns and health status in polar bears.

Jenny Bytingsvik is a PhD fellow on BearHealth.

23 May 2007: Endocrine-Disrupting Chemicals and Climate Change: A Worst-Case Combination for Arctic Marine Mammals and Seabirds? Download the paper which gives the background for our concerns about the future of polar bears.

Link to summary of the project

Link to Department of Biology, Norwegian University of Science and Technology (NTNU).

More information about NTNU and Trondheim.


Main aim of the project:

Identify region specific health effects (biomarker responses) of persistent organic pollutants (POPs) and climate change in polar bears.


-Identify interacting effects between exposure to POPs and climate variables on hormones and vitamins.

-Population specific effects of POPs on bone density and structure.

-Sampling of polar bears at Svalbard and in the Barents Sea.

-Compile data in a circumpolar context in co-operation with other international BearHealth partners.

Link to summary of the project

National partners:

Bjørn Munro Jenssen (co-ordinator) (homepage), Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim.

Jon Aars, Geir Wing Gabrielsen, and Hans Wolkers, Norwegian Polar Institute (NP), Tromsø

Øystein Wiig, Natural History Museum, University of Oslo (UiO).

Elisabeth Lie and Janneche Utne Skaare, Norwegian School of Veterinary Sciences (NVH) and National Veterinary Institute (NVI), Oslo.

International Partners

Christian Sonne (co-ordinator of the international BearHealth IPY project) and Rune Dietz, National Environmental Research Instiute (NERI), Roskilde, Denmark.

Stanislav Belikov and Andrei Boltunov, Ministry of Environmental Protection and Natural Resources, All-Russian Research Institute for Nature Protection, 113628 Moscow, Russia.

Robert J. Letcher, Wildlife Toxicology & Disease Program, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment Canada, National Wildlife Research Centre, Carleton University (Raven Road), Ottawa, ON, Canada.


Link to related publications on polar bears authored by the project participants.


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