Fishing for Dinner
How polar bears are changing with the climate
POLAR BEARS subsist mainly on a diet of seals, which they catch on sea ice. But sea ice is shrinking (see "Bering Sea Blues"), so what is a bear to do? According to a new study published in the journal Polar Biology, there is another option: dive for fish. Canadian researchers recently spotted an adolescent male bear swimming in an Arctic estuary, chasing down and eating char, a salmonlike fish--the first such sighting by anyone outside the Arctic's native Inuit population.--Hannah Schardt
A Slippery Future
Two-thirds of the world's polar bear population could disappear by the middle of the century if Arctic sea ice continues to vanish as predicted, according to a series of studies released late last year by the U.S. Geological Survey (USGS). Earlier, the U.S. Fish and Wildlife Service proposed listing the bear as threatened--a decision it will make sometime this year--and asked the USGS to weigh in on the bears' status.
Scientists from the USGS, other U.S. and Canadian government agencies and universities documented the direct relationship between Arctic sea ice and polar bear health and survival. The bears live on a diet heavily dependent on seals, which they hunt on sea ice. USGS models project a 42 percent loss of prime polar bear habitat in the coming years due to global warming. The scientists warn that their estimates are conservative, and that polar bears may face an even more dire future as Arctic sea ice begins to virtually disappear during the summer months.--Hannah Schardt