First tally of US-Russia polar bears finds a healthy population

Date:  November 14, 2018

Source:  University of Washington

Not all polar bears are in the same dire situation due to retreating sea ice, at least not right now. Off the western coast of Alaska, the Chukchi Sea is rich in marine life, but the number of polar bears in the area had never been counted. The first formal study of this population suggests that it's been healthy and relatively abundant in recent years, numbering about 3,000 animals.

The study by researchers at the University of Washington and federal agencies is published Nov. 14 in Scientific Reports, an open-access journal from the Nature Publishing Group.

"This work represents a decade of research that gives us a first estimate of the abundance and status of the Chukchi Sea subpopulation," said first author Eric Regehr, a researcher with the UW's Polar Science Center who started the project as a biologist in Alaska with the U.S. Fish and Wildlife Service. "Despite having about one month less time on preferred sea ice habitats to hunt compared with 25 years ago, we found that the Chukchi Sea subpopulation was doing well from 2008 to 2016.

"Sea-ice loss due to climate change remains the primary threat to the species but, as this study shows, there is variation in when and where the effects of sea-ice loss appear. Some subpopulations are already declining while others are still doing OK."

Of the world's 19 subpopulations of polar bears, the U.S. shares two with neighboring countries. The other U.S. subpopulation -- the southern Beaufort Sea polar bears, whose territory overlaps with Canada -- is showing signs of stress.

"The southern Beaufort Sea subpopulation is well-studied, and a growing body of evidence suggests it's doing poorly due to sea-ice loss," Regehr said.

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