A recently published study by Trent University scientists found that current genetic structure among polar bears may be impacted as climate change warms their Arctic habitat.

“Polar bears living along the shores of Hudson Bay show genetic subdivision corresponding not to their summer den sites when the sea ice has melted as we expected, but as a result of on-ice breeding areas during the spring.” explained Dr. Paul Wilson, an Associate Professor of Biology who also holds a prestigious Canada Research Chair in DNA Profiling, Forensics and Functional Genomics at Trent University. “These results were surprising given the extensive dispersal capabilities of polar bears that should homogenize the Hudson Bay population.”

The primary habitat for polar bears is sea ice, yet unlike most of the high Arctic, Hudson Bay undergoes a summer ice-free period that forces all bears ashore until ice forms again in fall.

Professor Wilson conducted this study with colleagues Ashleigh Crompton and Steven Petersen, both graduate students at Trent University, and Dr. Martyn Obbard of the Ontario Ministry of Natural Resources who is also an Adjunct Professor in Trent’s Environmental and Life Sciences Graduate Program. Together they identified three population clusters in the polar bears’ southern range along the shores of Manitoba and Ontario. Their study, which appeared in the October 2008 issue of the scientific journal Biological Conservation, suggested that these population clusters are maintained by on-ice breeding ‘groups’ resulting from predictable annual freeze-thaw patterns. Predicted changes in the distribution and duration of sea ice in Hudson Bay further suggest that gene flow among these breeding populations may be reduced or significantly modified in the future.

Scientists have confirmed that climate change is negatively affecting polar bears which rely on sea ice to access food. This new study is among the first to demonstrate seasonal genetic structuring that may be susceptible to climate change. Funding for this project was provided by the Natural Sciences and Engineering Research Council, the Ontario Ministry of Natural Resources, and World Wildlife Fund (Canada).

For more information about Prof. Paul Wilson’s research, please visit his website.