Climate change is responsible for the changes in diet and exposure to contaminants in polar bears

Global warming, one of the most troubling climate change has been associated with several changes in physiology and species distribution. In the Arctic, the increase of the average annual temperature is two to three times higher than the rest of the globe temperature. It also causes loss of an important ice habitat for the polar bear (Ursus maritimus).

In the East Greenland region, polar bear feeds predominantly on seals, mostly ringed seal (Phoca hispida), but also focuses on the Harp seal (Pagophilus groenlandicus) and hooded seal (Cystophora Cristata). Despite the ringed seal continuing to be the main prey, the polar bear diet has changed recently: the decline of Arctic ice extension caused the seal-hood to become more accessible to the polar bear. Increasing the proportion of this seal species on the polar bear’s diet, has resulted in the increase of persistent organic pollutants[1] in this species, since the hooded seal has higher contaminant levels than the ringed seal. This change in diet may have implications for their health and the polar bear development.

Ringed seal (left) and hooded seal (right)

[1] Persistent Organic Pollutants (POP): synthetic chemical used mainly in plague management in agriculture and industrial processes. These however have toxic effects on environment and health.



Mckinney M a., Iverson SJ, Fisk AT, Sonne C, Rigét FF, Letcher RJ, et al. Global change effects on the long-term feeding ecology and contaminant exposures of East Greenland polar bears. Glob Chang Biol. 2013;19: 2360–2372. doi: 10.1111/gcb.12241

Author: Sara Pedro