A female polar bear swam for nine days straight to find hunting grounds in the Beaufort Sea.

Her cub died during the 687-kilometre search for pack ice.

Researchers, who tracked the bear with a radio collar in the summer of 2008, published their findings in the scientific journal Polar Biology.

The article raises concerns that climate change is decreasing the amount of pack ice in the Arctic and is affecting polar bears’ hunting patterns.

“The extraordinary long distance swimming ability of polar bears, which we confirm here, may help them cope with reduced Arctic sea ice,” researchers concluded.