Marine mammals are threat to Chinook salmon on lower Columbia River

LEWISTON – An aerial survey of marine mammals in the lower Columbia River found spring Chinook salmon will have to make it past more than 6,000 hungry harbor seals, 1,500 California sea lions and 100 Steller sea lions.

The mammals are drawn into the river this time of year to take advantage of a smelt run, but will switch to spring Chinook by spring.

“We have more sea lions than ever in the Columbia, and they are there when endangered salmon and steelhead are there, and the smelt they are eating are endangered as well,” Steve Jefferies of Washington Fish and Wildlife told the Lewiston Tribune.

A study last year indicated as much as 40 percent of the spring and summer chinook run that enters the river disappears.

State fisheries managers have gotten permits to lethally remove some sea lions. In the past six years, about 50 animals have been killed.