Adult Steelhead Released To Boost Snake River Populations

Nov 22, 2019

Snake River Steelhead
Credit NOAA Fisheries

Efforts are underway to beef up the steelhead breeding population in the Snake River by releasing adult females that have already made one trip to the ocean and spawned previously.

Unlike salmon, steelhead can migrate to the ocean and return to spawn more than a single time. But few of the fish that have previously spawned make it that far back upriver after their first breeding because of the difficulty in migrating past all the dams.

Now, 27 wild adult female steelhead have been released into the Snake River below Lower Granite Dam.

The fish, known as kelts, have been rejuvenated in captivity for the past few months, rather than having to make the journey down to the ocean and back.

Doug Hatch is a senior fisheries scientist with the Columbia Inter Tribal Fish Commission, who says the kelts are a good breeding stock because they have more eggs than fish that have yet to make their first ocean migration.

“They do get larger with this extra year or two of life, so along with more size comes more eggs, and larger eggs which comes with better survival of juveniles. So if they re-mature after one summer, they usually have 30 percent more eggs than the first time spawners, or maiden spawners," Hatch said.

The wild steelhead run on the waterway is one of the worst on record this year, with only 700 fish expected to return from the ocean this fall.