Pacific Northwest
Some sockeye salmon are diseased and dying in the waters trickling out of the Little White Salmon hatchery pipe outflow, where they had sought refuge from the warming waters of the Lower Columbia River in southern Washington. (Steve Ringman / The Seattle Times, 2015)Less

WA - Climate change could make WA streams too hot for fish, report shows

A new report prepared for the state Department of Ecology suggests climate change will continue to alter Washington’s rivers, potentially making some watersheds uninhabitable for salmon and steelhead by the end of the century.

The report led by Washington State University researcher Jonathan Yoder and University of Washington researcher Crystal Raymond projects widespread increases in river flows in the winter, declines in the summer and rising stream temperatures.

Nothing in the report is revolutionary, said state climatologist Nick Bond, but it’s a substantial contribution to the conversation. “Climate change has emerged in the conditions we’re seeing here in Washington state,” he said.

End-of-winter snowpack is declining. Storm surges are getting more severe. Summers are becoming drier.

Western Washington rivers saw record low flows this fall, forcing some salmon to drop eggs downstream from their usual spawning grounds.

In 2015, high temperatures devastated the sockeye salmon run in the Snake and Columbia rivers. An estimated 250,000 sockeye died that year, long before reaching their spawning grounds.

Each of these trends will continue to affect the state’s freshwater highways, according to the report. But it’ll look a bit different depending on where you live.

Researchers analyzed existing studies, and used new data sets from the River Management Joint Operating Committee and the NorWeST modeling project to predict future streamflows and temperatures.

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