{"id":62086,"date":"2020-07-22T06:27:00","date_gmt":"2020-07-22T14:27:00","guid":{"rendered":"https:\/\/www.juneauempire.com\/news\/what-climate-change-means-for-alaskas-rivers-and-king-salmon\/"},"modified":"2020-07-22T06:27:00","modified_gmt":"2020-07-22T14:27:00","slug":"what-climate-change-means-for-alaskas-rivers-and-king-salmon","status":"publish","type":"post","link":"https:\/\/www.juneauempire.com\/news\/what-climate-change-means-for-alaskas-rivers-and-king-salmon\/","title":{"rendered":"What climate change means for Alaska’s rivers — and king salmon"},"content":{"rendered":"\n\t\t\t\t

A new study <\/a>found that the answer to Alaska’s Chinook salmon decline lies not just in the ocean, but also in freshwater rivers and streams — and that climate change’s effects on Alaska’s freshwater systems are affecting king salmon.<\/p>\n\t\t\t\t

“The take-home message is that what happens in freshwater really matters to the strength of our salmon runs in Alaska,” said University of Alaska Fairbanks research scientist Erik Schoen. “In a lot of ways, that’s good news, because we have some control over freshwater conditions in our salmon streams.”<\/p>\n\t\t\t\t

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A juvenile Chinook salmon swims in Campbell Creek. (Courtesy Photo | Ryan Hagerty, U.S. Fish and Wildlife Service)<\/p><\/div>\n\t\t\t\t

The study, led by the University of Alaska, with data from the Alaska Department of Fish and Game and Cook Inletkeeper and with help from additional authors, focused on 15 Chinook populations in Cook Inlet over a span of almost three decades. It found that above average rainfall in late summer and fall leads to fewer surviving Chinook — the rain moves gravel, which displaces eggs. Those findings may be relevant to other regions, even those, like Southeast Alaska, that are typically rainy in autumn. Since the key is “above average” rainfall, different river systems are adapted and optimized to different conditions, Schoen said.<\/p>\n\t\t\t\t

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An Anchor River gravel bar is seen at low water in September 2019.(Courtesy Photo | Sue Mauger)<\/p><\/div>\n\t\t\t\t

On the positive side, the study also found that higher-than-average summer rainfall during juvenile rearing was good for Chinook.<\/p>\n\t\t\t\t

[How salmon are connecting the nation amid COVID-19<\/a>]<\/ins><\/p>\n\t\t\t\t

Water temperatures above 64 degrees Fahrenheit for a week or more in the summer during spawning decreased Chinook productivity. In 2019, a year of record heat for the state, Alaska’s salmon made international headlines when water temperatures in some rivers rose above 80 degrees and thousands of salmon died of heat stroke before they could spawn.<\/p>\n\t\t\t\t

All of these things are happening more as climate change, which is warming Alaska at twice the global average, also changes Alaska’s rain, snowpack and glacial melt — and, accordingly, the flow, timing and temperature of its rivers. Climate change is also increasing “extreme precipitation events” across the state.<\/p>\n\t\t\t\t