A hulking, $60 million facility bobbing in Swift Reservoir resembles an oil rig or a small parking garage, but it’s a key to restoring salmon and steelhead to the upper Lewis River.
Monday, Pacific Power officials gave a tour of the company’s new fish collector, which will capture downstream-bound juveniles so they can be trucked around Pacific Power’s three Lewis River dams and have a better chance of making it out to the ocean to grow up.
Construction of the three dams — Merwin, Yale and Swift — in the 1930s and 1950s blocked migrating fish from using the upper Lewis, which once supported thick runs of salmon and steelhead. When the federal government renewed Pacific Power’s license for the dams in 2008, it ordered the company to restore those runs.
The floating fish collector is most expensive part of a $110 million Pacific Power project to restore salmon and steelhead to about 100 miles of river habitat. If successful, the collector will spare juvenile fish the perilous journey through three long, slackwater reservoirs and the dams’ spinning hydroelectric turbines. Work on the collector began in 2011, and the facility has been operating since March. It is anchored just east of Swift Dam.
The visible part of the collector is a mass of staircases, walkways and decks made of steel girders and metal grating. The facility is connected to land by a 660-foot-long trestle that allows trucks to pick up collected fish.
Under the quarter-acre floating structure, a “sluicing” mechanism generates a powerful current. That current guides fish inside, where an automated system counts them and channels them into a series of tanks with moveable sides and bottoms.
At any given time, two or three biologists are working there. They sort the fish by species, collect data, prepare the fish for transportation, and tag some of them for tracking, said Tom Gauntt, a spokesperson for Pacific Power.
Monday afternoon, two biologists used the facility’s hydraulic system to concentrate the fish in a smaller tank, and then raise the floor of the tank until the fish were at waist-level.
Using nets, they scooped the young fish into buckets, and carried them to a table where they could be measured and identified. Sometimes, the fish are placed in an anesthetic bath to sedate them and prevent injury. The facility must ensure that fewer than 2 percent of the fish are injured or killed, Gauntt said.
The fish were then moved to a portable tank.
One story above the tank, a truck backed into a loading bay. Slowly, a massive crane system hoisted the dripping tank over a truck, then lowered. A few moments later, the truck was carrying 105 smolts down the highway, past the river’s three dams, to a release point near Woodland.
The facility’s operators are still learning when peak fish migration occurs, said Chris Karchesky, who coordinates operations on the collector.
So far this year, the fish collector has captured between 600 and 700 fish on the heaviest days and caught a total of around 14,000 coho, 900 spring chinook, 950 rainbow trout and “a smattering of cutthroat and steelhead,” Karchesky said.
The system is designed to handle as many as 75,000 juvenile fish in a single day.
When salmon and steelhead adults return to the Lewis to spawn, they’ll be intercepted at the foot of Merwin Dam, where Pacific Power is building a $50 million collection facility. It will consist of a fish ladder and hoist, collection and sorting tanks and a truck loading system.
Once sorted, the adult fish will be loaded onto specially designed trucks that take them to the hatchery or upstream of the dams to be released and spawn naturally in the stream beds of the Lewis River and its tributaries.
TDN Online Editor; email: email@example.com
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