The surprising reason polar bears need sea ice to survive
A new study investigates an important link in the predators' food chain.
Every winter, Arctic sea ice grows around the pole, its frozen tendrils threading along northern coasts. Right now sea ice has just passed its peak coverage for the year, and will begin to shrink with the coming of spring. It’s a crucial time for polar bears, whose food supply is inextricably linked to sea ice.
And in recent decades, sea ice has been shrinking faster than ever. According to the National Snow and Ice Data Center, 2019 has the seventh-lowest sea ice cover in the Arctic since they began collecting satellite data 40 years ago.
This year “doesn't break any records, but it's the trend that matters,” says University of Alberta polar bear scientist Andrew Derocher. “The downward trend