Ontario, Canada.- Polar bears west of Canada’s Hudson Bay, in the southern tip of the Arctic, have died in large numbers, according to a new government study.
Female bears and cubs face the greatest difficulties. Researchers surveyed the western Hudson Bay region by air in 2021 and estimated there were 618 bears, compared with 842 in 2016, when the population was last surveyed.
“The actual decline is much greater than I would have expected,” said Andrew Derocher, a biology professor at the University of Alberta who has studied Hudson Bay polar bears for nearly four decades. Derocher was not involved in the study.
Since the 1980s the number of bears in the region has dropped by nearly 50 percent, according to the researchers’ findings. The ice, which is essential for their survival, is disappearing.
Polar bears depend on Arctic sea ice, the surface area of which shrinks in summer with warmer temperatures and re-forms in the long winter. They use it to hunt, perching near holes in the thick ice to spot seals, their favorite food. But because the Arctic has warmed twice as fast as the rest of the world due to climate change, the sea ice is breaking up earlier than usual and taking longer to freeze by the end of the year.
This has left many polar bears living in the Arctic with less ice in which to live, hunt, and breed. The researchers say the concentration of young and female bear deaths in western Hudson Bay is alarming.
“These are the types of bears that we have always predicted would be affected by changes in the environment,” said Stephen Atkinson, the lead author who has studied polar bears for more than 30 years.
Young bears need energy to grow and cannot survive long periods without enough food, and female bears suffer because they expend a lot of energy nursing and raising their cubs.
“It certainly raises feasibility issues,” Derocher said.
“That’s the reproductive engine of the population.”
The reproductive capacity of polar bears west of Hudson Bay will decline, Atkinson explained, “because there are simply fewer young bears that will survive to become adults.”
