Between 2001 and 2010, the polar bear population in the southern Beaufort Sea declined by 40 percent. That’s according to a new study published in the journal Ecological Society of America and researched by the U.S. Geological Survey and scientists from Canada and the U.S.
The Beaufort Sea, located just north of Alaska, has been gradually losing its sea ice. Essential to the survival of the region’s polar bears, its disappearance is considered by researchers to be a prime factor in the bears’ population decline.
According the study, survival rates for the bears were extremely low between 2004 and 2006, when just two out of 80 cubs reportedly survived. As the Beaufort’s winter ice has become thinner and more spread out, it has become much more challenging for bears to reach the seals that are so vital to their diet. While the bears can survive on other foods, seal blubber is “really what makes them work,” according to Andrew Derocher, a biology professor at the University of Alberta.
The Beaufort polar bears are just one of many polar bear groups that have shrunk over time. According to the International Union for Conservation of Nature, half of Canada’s 13 polar bear populations are now in decline. Derocher recently told Takepart that the Churchill group was about 1,200-strong 30 years ago. Since that time, the bears numbers have dwindled to about 800.
This year, the population in the Barents Sea, around the Arctic Svalbard islands, also appears to be suffering. A small survey group recorded only 10 percent of females giving birth to cubs. “This is a lower number than we would have expected,” Jon Aars of the Norwegian Polar Institute told the Guardian. “Typically one third or more of the adult females have cubs from that year.”
Sea ice is vanishing in this area as well, which not only affects polar bears. Walruses, such as those off the shores of eastern Alaska, have lost the floating ice they once used to dive for the snails, clams and worms that make up their main diet. This is why 35,000 of the creatures came ashore in Alaska this past month.