A total of 15 spring chinook have been trapped this year and transported around the Pelton Round Butte hydro project for release into Lake Billy Chinook to become the first of the species to ply the central Oregon waters of the Crooked, Metolius and upper Deschutes rivers in 50 years.
On Wednesday, they were joined by the first sockeye to knock on the door that is the Pelton Round Butte project, a series of three dams on the mid-Deschutes. The lowermost is about 100 miles upstream from the Deschutes’ confluence with the Columbia River. The upper Deschutes, Crooked and Metolius converge above Round Butte to form what becomes the Deschutes River.
The fish trapped and transported around the dams are so-called “known origin” salmon that were specially marked as juveniles after swimming into a new collection facility just upstream of Round Butte Dam. Those juveniles were transported past the dam and released so they could continue their migration toward the Pacific Ocean.
The hitch-hike rides are part of an effort aimed at re-establishing anadromous fish populations that were cut off by the construction of the Pelton Round Butte Dam complex on the Deschutes River in the early 1960s.
Adult upriver chinook returning to the dam this year, and the expected upriver steelhead yet to arrive, began life in the Round Butte Hatchery. But as part of the reintroduction program they were released as young fish into upstream habitats in the rivers. That program began in 2007.
Portland General Electric and the Confederated Tribes of Warm Springs, co-owners of the Pelton Round Butte Hydroelectric Project, constructed and began operating the fish collection facility at Round Butte Dam in 2009 to capture the outmigrating smolts.
A certain share of those juvenile fish were expected to mature in the Pacific Ocean and return to the river to spawn.
A total of 44,000 spring chinook, 7,700 steelhead, and 49,700 kokanee were passed downriver in 2010. And they are expected to produce the first significant number of adult fish to return to the dam complex this summer and fall.
Kokanee are landlocked salmon that are essentially the same species sockeye, which are spawned and achieve their early rearing in freshwater, go to the ocean to mature, and return to freshwater to spawn. The kokanee set free below the dams are of natural origin.
Last year seven spring chinook from above the dam returned. They are fish that were trapped in the tributaries and hauled downstream in 2009 before the collection facility was working. All were taken into the hatchery as broodstock. A total of 19 “one-salt” sockeye also returned from the 2010 outmigration. These were kokanee – believed to have a yen to adopt the anadromous, ocean-going life style -- that were drawn into the juvenile collection facility and transported around the dams.
The projected return this year of upstream origin spring chinook is 400 fish, a number based on the recent average smolt-to-adult returns for of hatchery fish produced at the Round Butte Hatchery operated by ODFW and funded by the utility.
“We thought we’d do better than that,” PGE’s Don Ratliff said of the 2012 return.
There are no recent sockeye returns on which to base return estimates for 2012.
Many of these fish will be fitted with radio tags so biologists can study their migration behavior and spawning locations.
The 2012 fish passage management strategy calls for half of the fish to be trapped and hauled around the dams, and then allowed to continue their spawning journey.
The other half of the fish will be taken to the Round Butte Hatchery and used as broodstock to produce young fish for release into upstream habitats in 2013. The hatchery produces spring chinook and steelhead primarily for downstream harvest. It has now added sockeye.
So far a total of 48 adult “known origin” chinook have been captured at the Pelton trap, located below that lowermost dam. A total of 23 have been released upstream and 15 of them have been outfitted with acoustic tags. The other 25 were taken to the hatchery for use as broodstock.
“The last fish we tagged was June 25,” PGE biologist Megan Hill said of a spring chinook return that has not matched expectations.
Those above-dam releases have fanned out.
“We are seeing quite a few fish in the Metolius,” Hill said. The last known location of seven of the radio tagged fish were at the upper end to the Metolius arm of the reservoir. Two of the tagged fish were located in the Deschutes arm of the reservoir and four were in the Crooked River, including one that had hopped Opal Springs Dam with the help of a temporary fish ladder and trap. Deschutes Valley Irrigation District personnel plucked the fish from the trap and lifted over the dam. The irrigation district owns the dam and is planning to build a permanent fish ladder at the facility for the salmon and steelhead that are being introduced above Pelton Round Butte.
“We have a couple other fish that are in the upper Crooked” downstream of Opal Springs, Hill said. Opal Spring is located at river mile 7, just upstream from the confluence of the Crooked River and the Deschutes River, which meet at Lake Billy Chinook.
Researchers monitoring the upstream fish employ data collected from five fixed location receivers – one near the mouth of each river, on upstream in the Metolus and one in the upper Deschutes. The monitoring also involves mobile monitoring.
The 2012 Pelton Round Butte fish passage strategy was developed in conjunction with the Pelton Round Butte Fish Committee, which includes representatives from the U.S. Fish and Wildlife Service, National Marine Fisheries Service, U.S. Forest Service, Bureau of Land Management, Bureau of Indian Affairs, PGE, ODFW and non-governmental organizations.