Coho salmon bound for the Snake River basin are making a strong showing at Bonneville Dam this fall, and fisheries officials at the Nez Perce Tribe expect as many as 10,000 to return to the Clearwater River.
Coho in the Clearwater were driven to extinction after construction of the Lewiston Dam in 1927. The Nez Perce Tribe started a reintroduction program on a shoe-string budget in 1994, and have slowly built the program to its present state, where it appears poised to set a new high mark.
“The (long-term) goal is to return about 15,000 fish up here,” said Becky Johnson, director of fish production for the tribe’s fisheries division. “If we get 10,000 up here, that would be phenomenal.”
About 26,000 coho bound for the Clearwater have already passed Bonneville Dam on the Columbia River. Johnson said coho are harvested in tribal fisheries above Bonneville Dam.
“There has been in the past fairly substantial harvest on those fish, and that is really one of the purposes for their production,” she said.
Coho are also harvested in the Clearwater River during tribal gill net seasons. Adults have just started to show up at Lower Granite Dam on the Snake River, and numbers should be on the rise the rest of this month and into October. The fish will be trapped and spawned in November and early December.
Eventually, the tribe’s reintroduction program envisions both sport and tribal harvest of the fish but there is no sport seasons at this time.
“Our goal would be to provide harvest for tribal and non-tribal (anglers),” she said.
The coho program was started from a surplus of eggs at hatcheries on the lower Columbia River. Early on, the tribe out-planted the eggs. Later it secured space at lower Columbia River, where juveniles were raised and then trucked upriver for release in the Clearwater Basin. Now the tribe raises about 300,000 coho at Kooskia and Dworshak national fish hatcheries, and another 550,000 at lower Columbia hatcheries.
For years, the tribe worked to develop a local brood stock. Fisheries officials took eggs from adult coho that returned to the Clearwater and used them to raise juvenile fish and slowly reduced the number of eggs taken from Columbia River coho. Starting in about 2011, adult returns to the Clearwater were strong enough that the tribe no longer needed to use eggs from adults that returned only as far as the lower Columbia.
Johnson said developing a local stock should lead to higher returns in the future. The theory is that the progeny of adult that have proven they have the fitness to return more than 500 miles from the ocean, should return at a higher rate than the offspring of fish that only return to the lower Columbia.
“It would make sense its progeny would be (more) suited to make that long journey than a fish from the lower river that doesn’t have to go that far,” she said
The Yakama Tribe started a coho program in upper Columbia River tributaries and saw a boost in returns once it was able to establish a local brood stock, Johnson said.
The tribe also hopes to raise an additional 500,000 juvenile coho in the near future. The Umatilla Tribe also had a coho program and raises about 1 million juveniles per year. Johnson said the Umatilla Tribe plans to reduce its coho production by about half, and the Nez Perce Fisheries Division has secured the hatchery space made available by the reduction. The extra space will allow the Nez Perce to raise about 1.4 million coho.
“The long-term plan for that group of fish (the extra 500,000) would be to eventually put them back into the Wallowa River in northeastern Oregon,” she said. “In the short term, those fish are going to come to the Clearwater.”
The juveniles that are raised at lower Columbia hatcheries are trucked to the basin and released directly into Lapwai and Clear creeks. Johnson said the tribe recently received funding to build acclimation tanks at those two sites.
“We hope it will improve out survival,” she said. “It will give them a chance to rest and recover after their long trucking experience.”
