US: Pacific salmon move north to Arctic Canada from Alaska when ocean conditions allow

As the climate warms, more Pacific salmon from Alaska are showing up in the Western Arctic waters of Canada. But residents in those Arctic Canadian communities are not catching salmon every year, which led them to ask why. Now a study by scientists from Canada and Alaska has described the ocean gateway that must open to bring salmon from the Bering Sea to those far-north sites. Conditions must line up over vast stretches of ocean for salmon to make the journey through the Bering Strait, across the Chukchi Sea and into the Canadian Beaufort Sea and the freshwater bodies upstream from it, the scientists found. “What appears to need to happen is you need a warm late springtime Chukchi sea,” said Joe Langan of the University of Alaska Fairbanks, one of the lead authors of the study, published in the journal Global Change Biology. Those conditions probably correlate with a warm Northern Bering Sea, he said, adding that beyond the Chukchi, a warm coastal Beaufort Sea is also necessary. ...