Humans have been eating salmon in Alaska for 11,000 years. The cold-water fish is a protein powerhouse and Alaskan wild salmon is beyond delicious.
In a heating Arctic, the consequences of our fossil fuel emissions are coming under intense scrutiny. This summer in the Arctic, heat records were smashed, sea ice loss and raging wildfires have been dramatic and more startling than in years past.
River water in Alaska has been warming and any water temperature over 70 F is lethal for salmon. The warm water is a direct result of the changing Arctic climate.
River water fed by the record-demolishing and horrifyingly warm surface water in the Bering Sea this summer provided the temperature boost via high tide to the “principal drainage for an area of the remote Alaska Interior on the north and west side of the Alaska Range, flowing southwest into Kuskokwim Bay on the Bering Sea.
Residents along the lower Kuskokwim River from Tuntutuliak to Akiak reported dead salmon floating downstream. Salmon don’t function well past 70 degrees, and the water had pushed just above that limit.
“Essentially, what could happen is salmon metabolism speeds up to the point that they’re having heart attacks and going belly up and floating downriver,” explained Alaska Department of Fish and Game biologist Ben Gray.
Warm water is also the suspected cause of the higher than normal amount of parasites infesting salmon harvested along the river. That warm water is coming from the ocean. Kuskokwim Bay has run 10 to 12 degrees above average throughout the summer, and each tide pulls that warm water into the lower river.
“And that water is pushing upriver,” Gray said, “and it’s mixing, and we’re having a profile in the water right now where it’s a solid 68 to 70 degrees all the way through.”
Meanwhile, residents throughout the Norton Sound region to the north have reported large numbers of dead pink salmon that have yet to spawn floating in warm waterways.