Adult tule fall chinook salmon trapped this late summer and early fall in the lower White Salmon River and transported upstream above Condit Dam were “highly successful” in their spawning efforts, according to biologists that monitored the effort.
There was no sign of prespawn mortality, i.e. females dying before they lay down their eggs, among the 120 carcasses found along the southwest Washington stream. That’s fact that is stunning, as in stunningly good, according to U.S. Fish and Wildlife Service biologist Rod Engle.
“Those fish put their eggs in the grounds,” Engle said of gravel redds or nests built by the fish.
The trapping was conducted in order to prevent the fish from putting those eggs down in the lower three miles of the river. If planted there biologists believed the eggs would be suffocated by a flood of sediment that was to be swept downstream Oct. 26 when a dynamite blast cleared a tunnel built through the base of Condit and emptied the content of its reservoir, Northwestern Lake.
The tunnel is the beginning of the end for Condit, which has since the early 1900s blocked fish passage to habitat upstream that had historically been used by salmon and steelhead, and likely lamprey as well. The dam will be removed next spring and summer.
(For more information see CBB, Oct. 28, 2011, “Blast Drains Condit Dam’s Reservoir On White Salmon River; Dam Structure Removal Set For Spring 2012” http://www.cbbulletin.com/413585.aspx)
Meanwhile any young fish produced from this year’s spawning should be able to make their way down stream through the tunnel on their way to the Columbia River and then the Pacific Ocean. And any of their number that survive to return to freshwater as adults should have clear path up the White Salmon.
Condit's removal opens an additional 5 miles of spawning grounds for fall chinook and up to 33 miles for steelhead. Both species are protected under the Endangered Species Act.
The White Salmon Working Group, which is a consortium of Yakama Nation, federal, state, and PacifiCorp biologists, estimates the White Salmon River has enough spawning grounds to accommodate more than 600 steelhead spawners and 1,200 fall chinook. Bull trout, coho, lamprey and spring chinook could also benefit from a reconnected river. Pacificorp owns the dam.
The working group came up with the plan to trap and haul spawners upriver so they could build redds where they wouldn’t be covered by sediment.
Four surveys conducted Oct. 18-20 in areas considered to be prime spawning habitat turned up 180 redds. That count would be the minimum estimate, given the fact that redds built in deeper water can easily be missed, and the fact that only a portion of the available habitat was surveyed.
“You can only see redds that are in pretty shallow water,” said the USFWS’ Joe Skalicki.
A total of 679 tule spawners were trapped and hauled above the dam, which is well above the goal of moving at least 500 fish. Of that total 299 or about 45 percent were females. The fish were mined for genetic samples.
“It’s amazing, I don’t even know what to say,” Engle said of the prospect of those higher reaches of the White Salmon returning to salmon productivity after being idle for nearly 100 years.
Those involved in the project hope to be able to set up a so-called screw trap in the river next year so they can trap a sampling of any juvenile fish that might be migrating toward the ocean. That would give biologists an idea about the productivity of this year’s spawners, and again take genetic samples so they can start building fish family trees. The USFWS through its Abernathy Fish Technology Center plans to verify genetic lineages of wild stocks in the river, and initiate plans to monitor how those populations are faring after dam removal