Sean Kilpatrick/The Canadian Press via AP, file
Polar bears in Canada’s western Hudson Bay — on the southern edge of the Arctic — continue to die in large numbers, a new government survey of the land carnivore has found. Females and bear cubs in particular are having a hard time.
Researchers surveyed Western Hudson Bay — home to Churchill, the city dubbed “the polar bear capital of the world” — by plane in 2021 and estimated there were 618 bears, compared to 842 in 2016, when they were last surveyed .
“The actual decline is much greater than I expected,” said Andrew Derocher, a biology professor at the University of Alberta who has studied polar bears in Hudson Bay for nearly four decades. Derocher was not involved in the investigation.
Since the 1980s, bear numbers in the region have declined by nearly 50%, the authors found. The ice essential to their survival is disappearing.
Polar bears depend on arctic sea ice — frozen ocean water — which shrinks in the summer at higher temperatures and forms again in the long winter. They use it for hunting, perched near holes in the thick ice to spot seals, their favorite food, that come up for air. But since climate change has warmed the Arctic twice as fast as the rest of the world, sea ice breaks earlier in the year and takes longer to freeze in the fall.
As a result, many polar bears living in the Arctic have less ice to live, hunt and reproduce on.
Polar bears aren’t just critical predators in the Arctic. For years, before climate change started to affect people around the world, they were also the most famous face of climate change.
Researchers said the concentration of deaths among cubs and females in western Hudson Bay is alarming.
“These are the types of bears that we’ve always predicted to be affected by environmental changes,” 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 adequate food and female bears struggle because they spend so much energy caring for and raising offspring.
“It certainly raises questions about continued viability,” Derocher said. “That’s the population’s reproductive engine.”
Polar bears in western Hudson Bay’s ability to reproduce will decline, Atkinson said, “because you just have fewer young bears surviving and reaching adulthood.”