Hot water kills half of Columbia River sockeye salmon

Drought and record heat are behind the high water temperatures

Dead salmon from the Clackamas River, June 19 2015. (KOIN)
Dead salmon from the Clackamas River, June 19 2015. (KOIN)

PORTLAND, Ore. (KOIN) — More than a quarter million sockeye salmon returning from the ocean to spawn are either dead or dying in the Columbia River and its tributaries due to warming water temperatures.

“The fish are not looking in good condition,” fisherman Nick Blevins told KOIN 6 News. “Some of them will have lesions on them from the scars they get.”

Federal and state fisheries biologists said water that is 5 to 6 degrees warmer is wiping out at least half of this year’s returning population of the cold-water species.

Ritchie Graves of the National Oceanic and Atmospheric Administration said up to 80% of the population could ultimately perish.

“Any sockeye that are through this area in lower river and haven’t passed McNary Dam yet, they are probably not going to make it up here into the Okanagan system to spawn,” fish biologist Ron Roler said.

Officials are trying to cool flows by releasing cold water from selected reservoirs.

“We are looking at moving water through the system from Canada to try and keep things cool,” Roler said. “All we can do now is wait for a timely rain and cool down so they can continue on.”

Experts said drought and record heat this summer are behind the high water temperatures.

Thirteen species of salmon and steelhead are listed as endangered or threatened in the Columbia River basin.

The Associated Press contributed to this report

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