Polar bears are struggling to survive as sea ice dwindles. Scientists have now quantified how much climate change has drastically reduced the number of polar bears living in Canada's Hudson Bay, the most studied group of polar bears in the world. The melting of the sea ice has shortened the polar bears' feeding season, which has resulted in an energy deficit for the bears for longer stretches of the year, Louise Archer, lead author of the study and international post doctoral fellow at the University of Toronto, Scarborough, told ABC News.
Researchers have known for some time that the population is in trouble, Peter Molnar, senior author of the study and associate professor at the University of Toronto, Scarborough, told ABC News.
They created a bioenergetic model that could incorporate the different ways the polar bears have been affected by sea loss, Archer said.
Combined with analysis of four decades of research on the Hudson Bay population, the scientists were able to determine the underlying mechanisms driving these changes. Sea ice is crucial to polar bear survival because they use it to hunt their main source of food -- seals.
Polar bears also use the ice as a platform to catch the seals, Archer said. Without the ice, they are forced to hunt in open water, which is a difficult feat for the large apex predator. The vast majority of their feeding and energy intake happens when the bears are moving around and roaming across the ice and hunting seals, Archer said.
