Polar bear declines in western Hudson Bay ‘far greater’ than expected, researcher says. News Jani

Polar bears in Canada’s western Hudson Bay — on the southern edge of the Arctic — continue to go extinct in large numbers, a new government census of terrestrial carnivores has found. Females and bear cubs have a particularly difficult time.

Researchers surveyed western Hudson Bay – home of Churchill, known as the “polar bear capital of the world” – by air in 2021 and estimated there were 618 bears, compared to 842 in 2016 when they conducted the last survey.

“The actual decline is much larger than I expected,” said Andrew DeRocher, a University of Alberta biology professor who has studied polar bears in Hudson Bay for nearly four decades. Derocher was not involved in the study.

The authors found that bear numbers in the region have declined by about 50 percent since the 1980s. The ice necessary for their survival is disappearing.

Polar bears depend on Arctic sea ice — frozen seawater — that shrinks with warmer summer temperatures and forms again during long winters. They use it for hunting and sit near holes in the thick ice to catch seals, their favorite food that comes up for air.

But because the Arctic has been warming twice as fast as the rest of the world due to climate change, sea ice is breaking up earlier in the year and taking longer to freeze in the fall.

As a result, many arctic polar bears have less ice on which to live, hunt and breed.

Polar bears are not only important predators in the Arctic; For years before climate change started affecting people around the world, he was also the most famous face of climate change.

The concentration of mortality among young bears and females in western Hudson Bay is alarming, the researchers said.

“These are the types of bears that we always predicted would be affected by changes in the environment,” said Stephen Atkinson, who has studied polar bears for more than 30 years. The research was conducted as part of a joint partnership between the Nunavut and Manitoba governments.

Young bears need energy to grow and cannot survive long without enough food, and female bears struggle because they expend so much energy caring for and raising their offspring.

“It certainly raises questions about continued engagement,” DeRocher said. “It’s the reproductive engine of the population.”

Polar bears’ ability to reproduce in western Hudson Bay will decrease, Atkinson said, “because there are fewer young bears surviving to adulthood.”