Experts expected to find more fish when rerouting creek for salmon
By Dylan J. Darling / The Bulletin
Published: March 02. 2012 4:00AM PST
Switching the course of Whychus Creek through Camp Polk Meadow Preserve on Tuesday revealed the fish within its waters. There were fewer than federal scientists had expected.
Environmental plans written for the shifting of the creek’s course estimated scientists could rescue as many as 5,800 Oncorhynchus mykiss — known as rainbow trout when they spend their lives in rivers and steelhead when they swim out to sea — said Jennifer O’Reilly, a biologist for the U.S. Fish and Wildlife Service. Experts also predicted that the course-change effort could kill 2,000 fish.
In reality, only 357 living Oncorhynchus mykiss — and about 10 dead ones — were salvaged from the creek.
“So we thought there would be quite a bit more fish,” she said.
As part of an effort to restore native salmon and steelhead runs on the Deschutes River, state and federal agencies joined with nonprofit groups to reroute just under two miles of Whychus Creek near Sisters. In 2000, The Deschutes Land Trust bought the 145-acre property, which had been subdivided into about a half-dozen homesites, then created the preserve.
Scientists wanted to change the channels in winter, when water would be high and fish wouldn’t become stranded in warm pools, O’Reilly said.
After excavators and bulldozers plugged the old channel off with about 10,000 cubic yards of dirt, the water drained out over a couple hours.
The slow drain might have given fish in the creek a chance to swim downstream and avoid becoming stranded, leading to the disparity in expected and collected numbers, O’Reilly said.
She said the predicted numbers were based on the number of Onchornynchus mykiss fingerlings released in recent years at Whychus Creek.
More than 275,000 steelhead fry have been released into the creek each year since 2007, said Steve Corson, spokesman for Portland General Electric. The company co-owns dams on the lower Deschutes River with the Confederated Tribes of Warm Springs.
The company and tribes spent $100 million to build a submerged tower that since 2009 has helped salmon and steelhead gain downstream passage around the dams. Salmon and steelhead have been released into tributaries like Whychus Creek over the last four years in order to build up the “seed stock” of young fish swimming downstream and past the dams, Corson said.
Officials plan to release chinook salmon into Whychus Creek’s new channel next week. The new course features more bends and pools, providing refuge and rearing habitat for fish.
“It should provide excellent fish habitat,” she said. “I imagine the number will greatly increase in the new channel.”
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