For the first time since the 1960s spring chinook salmon – two so far – have made the round trip from central Oregon’s upper Deschutes River to the Pacific Ocean and back again to become the initial fruits of reintroduction efforts.
The two fish were trapped May 25 and May 31 below the Pelton-Round Butte complex of three dams near Madras and taken to the Round Butte Hatchery to be used as part of the broodstock to produce a new generation of fish.
The goal, least to start, is to use of the two fishes’ genetic material by spawning them in the hatchery and next year outplanting their progeny in the upper Deschutes basin, according to Mike Gauvin of the Oregon Department of Fish and Wildlife. The survival of the young fish to fry stage is much higher in the hatchery than in the wild. And since there are no other adults above the dam, it would be highly unlikely that the two returned fish would even find each other to reproduce even if they were male and female.
“It’s really exciting to see that, (the first two fish) completing the cycle,” Gauvin said. Eventually, when and if annual returns have grown, spawners originating from upstream will be trucked past the dams and allowed to spawn on their own.
The fish are marked with a right maxillary fin clip so they can be identified as fish outplanted above the dams as fry. Many are also implanted with PIT tags so their presence can be detected as they pass through facilities such as Bonneville Dam on the lower Columbia River. The Deschutes feeds into the Columbia.
“We have had three adults that definitely passed Bonneville” so far, said Jim Bartlett, a Portland General Electric fish passage biologist
The hatchery has been the source of spring chinook salmon fry that have since 2008 been transported each year above the dams and outplanted in the Deschutes, Crooked and Metolius rivers and tributaries with the hope that they would grow and, a year later, head for the ocean. An ultimate goal is to trap returning adults and transport them around the dams for release so they can spawn on their own.
Biologists involved in the reintroduction project have been encouraged at the arrival of what are classified as 4-year-old fish. Only 1,300 spring chinook smolts made their way downriver in 2009, the year that the two spawners would have headed toward the ocean.
Completion of a massive 273-foot-tall underwater tower and fish collection facility, originally scheduled for completion in May 2009, was delayed when a portion of its 140-foot-long steel conduit, which is 40 feet in diameter, connecting its top and bottom structures broke off April 11, 2009, during assembly in Lake Billy Chinook in the forebay of Round Butte Dam. The tower was designed to create welcoming currents in the lake and allow the selective release of water at a variety of temperatures.
Because of the failure of the fish collection facility, an effort was launched to trap the young fish in the tributaries so they could be hauled downstream for release below the dam. Only about 700 were sent downstream that spring.
After the tower was resurrected, another 400 hatchery fish were used in December to test the collector-separator’s machinery before the facility was made fully operational. Another 240 fish that had been outplanted upstream were collected and transported after the facility went into operation in December 2009. Those latter two groups could also be the source of adult returns.
The dams were originally constructed with both upstream and downstream fish passage facilities but the young fish were largely unable to find their way down through the reservoir to the dam.
With no way for the young fish to migrate downstream, it became pointless to provide upstream passage for the adult fish. So in 1968, the program that used the upstream fish ladders was terminated and a fish hatchery was built below the dams to maintain the fish population in the lower Deschutes.
As part of the relicensing agreement with the federal government for use of the Pelton Round Butte dams, PGE and the Confederated Tribes of Warm Springs, as co-owners of the hydro project, worked to resolve fish passage issues. Since 1995, they have collaborated with over 22 organizations and agencies to study the situation and come up with solutions.
The reintroduction began with the first outplanting of steelhead in 2007.
From 2008-2010 a total of 1.26 million chinook fry were outplanted in the Metolius (including in tributaries Lake and Spring Creek), the Crooked River (including Ochoco and McKay creeks) and the upper Deschutes (including Whychus Creek). About 547,000 spring chinook fry were outplanted this spring.
In the tower’s first year of operation, 2010, more than 129,000 outmigrating fish were captured and transported downstream, including 50,000 kokanee/sockeye salmon, 44,270 spring chinook salmon and 7,800 steelhead smolts.
This year so far the kokanee/sockeye numbers so far have soared. Biologists had through May 31 collected and transported 209,997.
“It’s phenomenal,” Bartlett said. Kokanee are a popular sport fish that are spawned primarily in the Metolius and grow to adulthood in the reservoir. They are also called “landlocked salmon,” and are actually sockeye salmon that do not move to the Pacific Ocean.
Gauvin said that a recent hydroacoustic survey of the lake showed 300,000 spawning age in the lake, which is a strong showing.
Anadromous (ocean-going) sockeye salmon historically spawned in upper Metolius basin in Link Creek and reared in Suttle Lake before migrating down Lake Creek, and the Metolius, Deschutes and Columbia rivers to the ocean. The sockeye and other anadromous fish runs disappeared after dam construction, including barriers built in the 1950s and 60s on Lake Creek. But those sockeye eventually served to seed Lake Billy Chinook.
So far this year 23,361 spring chinook and 67,065 steelhead have been collected, Bartlett said.
“I actually think we’ve seen it peak,” Bartlett said of the outmigration. A few weeks ago there were daily collections of up to 16,000 fish and tanker truck drivers were making the 10-mile trip downstream five to seven times per day. Collections in recent days were down to about 3,000 fish.
The collection facility has also drawn in 160,749 adult kokanee so far as compared to 25,424 in 2010. The adults are separated from the young fish and released back into the reservoir.
In total through May 31 a total of 402,952 fish have been collected as compared to 129,000 for the entire 2010 season.
“I’d say the reservoir is starting to set up,” Bartlett said of the goal of using the water withdrawal tower to change the temperature stratification and currents in the reservoir.