Scientists have reported a sharp decline in the number of polar bears in the Beaufort Sea region of Alaska. As it turned out, animals migrate due to the melting of sea ice.
Scientists have already noticed that polar bears are forced to move to new territories and go far beyond the traditional Arctic habitats. This led to a population decline of almost 30%. Bears’ range, or the space they need to obtain food and other resources, was about 64% larger in 1999-2016 than in 1986-1998, according to new research published in the journal Ecosphere.
For the study, scientists from the US Geological Survey used satellite data to analyze the movement patterns of female polar bears between 1986 and 2016 in the Beaufort Sea region north of Alaska.
Their work has shown that over the past two decades, polar bears have had to move further north from their traditional hunting grounds on the continental shelf in order to stay in an area where there is a habitual amount of sea ice and food.
Having to travel long distances means that bears expend more energy, which can threaten their survival. If we want to preserve the habitat of these amazing mammals, then we need to focus on the root of the problem – slowing global climate change.
Another finding from the study is that about 20% of the polar bear population in the Beaufort Sea completely abandons traditional hunting grounds on sea ice in summer and autumn. These bears move deep into the coast of Alaska and Canada in search of food – carrion, berries and bowhead whale carcasses, which are left on the coast by the indigenous people who hunt large mammals.
“Sometimes 50 to 100 polar bears congregate around these whale carcasses and compete with each other for food,” the researchers noted. “As more and more bears migrate to land, competition for food resources will increase and we will likely begin to see further declines in animal numbers.”
The U.S. Geological Survey is planning a second wave of research on inland polar bears to better understand how they deal with their new habitat. The best thing people can do to conserve the remaining polar bears in the southern Beaufort Sea is to focus on limiting global carbon emissions, which are the main cause of Arctic sea ice reduction, employees said.