The number of polar bears in Western Hudson Bay in Canada has fallen by 27% in the past five years, according to a government report released this month.
The study, which was conducted in late August and early September 2021, estimated that there are now only 618 polar bears in the southern tip of the Canadian Arctic, down from 842 in 2016. The population of adult females and cub bears has seen the most dramatic decline.
Also of concern to researchers, declines appear to have accelerated: the population decreased only 11% from 2011 to 2016.
“Comparison to aerial surveys estimates from 2011 and 2016 suggests that the WH (Western Hudson Bay population) may be decreasing in abundance,” the study said.
The researchers pointed to climate change, which has caused the bears’ sea-ice habitat to disappear at an alarming rate, as a reason for the decline.
In the far north, temperatures are rising at a rate four times faster than in the rest of the world. Sea ice has become thinner causing it to break up earlier in the spring and freeze later in the fall. This is a significant problem for the bears, who rely on the ice for food, movement, and reproduction.
Scientists added that climate-caused changes in the local seal population -main food of polar bears- might also be driving polar bear numbers down.
A report published in the journal Nature Climate Change two years ago suggested that this trend could lead to the extinction of polar bears. In the 1980s, there were 1200 polar bears in Western Hudson Bay.
“The observed declines are consistent with long-standing predictions regarding the demographic effects of climate change on polar bears,” the researchers said.
The Western Hudson Bay polar bear population is the best-studied and most famous in the world, with the town of Churchill, a tourist destination called ‘polar bear capital of the world’, located within the region. The local bear-viewing economy in the town is a million-dollar business.
Polar bears live in 19 populations in Canada, Russia, Alaska, Greenland, and Norway. Scientists predict the bears here will likely be among the first to disappear in Western Hudson Bay, which is one of the most southern locales.
“What’s really sobering is that these kinds of declines are the kind that unless sea ice loss is halted, are predicted to eventually cause … extinction,” said John Whiteman, Chief Research Scientist at conservation non-profit Polar Bears International.