121 Polar Bears Captured

The animals were captured by remote drug injection from a helicopter. The samples collected during the expedition will be used for aging of the bears and studies on genetics, diseases and toxicology. The data will be used in survival analyses.

Twenty adult female bears also got satellite telemetry tags that will allow analyses on movements and swimming behaviour.

Anthropogenic (man made) pollution and climate change are the two most significant threats for Arctic biodiversity and ecosystem functioning. The expedition is part of the IPY-project BearHealth which focuses on the effects of toxicant exposure and climate change on the health of polar bears.

In addition to the capture of polar bears, main denning areas were mapped. This is the initiation of a study which will analyse how local sea ice conditions influence the distribution of maternity dens in Svalbard. 

The high number of animals captured was due to both cold and good weather, allowing helicopter flying most of the survey days. The temperature was between -15 and -29 degrees C most of the period.

Foto: Nymoen
 

At the top of the food chain
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 been 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, the project BearHealth states on its web pages.

Read more on the project's own web pages

Hear report from 2007 about BearHealth on BBC here.