Heat waves heat up water and cause salmon to die in Alaska

Alaska is experiencing an unprecedented wave of sunshine this summer, causing salmon to die massively due to the unbearable hot water .

Scientists observe the collective deaths of some Alaska salmon species, including red salmon, dog salmon and pink salmon . Stephanie Quinn-Davidson, director of the Yukon Fisheries Commission, led the study during an expedition along the Koyokuk River in late July after local people reported seeing dead fish on the stream.

Pink salmon dead in Alaska.(Photo: Anchorage Daily News).

Stephanie and other scientists counted 850 intact salmon fish on that expedition and estimated the total number of dead fish to be four to 10 times greater. They found no signs of injury, parasites or infectious diseases. Nearly all the salmon they find contains eggs. Because mass deaths occur at the same time as the heat wave, the team concludes that heat is the cause of dead fish. Stephanie said she had never encountered so much salmon in eight years of research.

Alaska's water temperature also broke the record like air temperature, according to Sue Mauger, scientific director of Cook Inletkeeper. Researchers track spring water temperatures around Cook Bay south of Anchorage since 2002. Previously, they had never measured temperatures higher than 24.4 degrees Celsius. , a large stream of many salmon in the west of Cook Bay reached temperatures of up to 27.6 degrees Celsius. "2019 temperatures far exceed the heat we anticipate for the worst case in 2069" , Sue said.

According to Sue, high temperatures affect salmon in many ways."Salmon cannot circulate oxygen through the abdomen. They have no energy to lay eggs and die with healthy eggs in the abdomen," Sue explained.

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