By The Numbers:Trapping,Transporting Salmonids In Reintroduction Efforts In Blocked Upper Deschutes
Feb 16, 2018
The Columbia Basin Fish and Wildlife News BulletinPortland General Electric biologists are continuing to transport salmon and steelhead adults trapped downstream of the Pelton Round Butte Complex of dams on the Deschutes River and transporting them up into Lake Billy Chinook in their efforts to reintroduce the fish to blocked areas in the upper Deschutes basin.
The utility, along with the Confederated Tribes of the Warm Springs Indian Reservation and Oregon Department of Fish and Wildlife, biologists have been transporting the trapped adults since 2012, when the first adults from the reintroduction program began to arrive.
Each year as they arrive at the base of the dam, the biologists trap spring chinook salmon, sockeye salmon and summer steelhead and once released into the lake the fish choose their own sometimes meandering path to one of reservoir’s tributaries (Deschutes, Crooked and Metolius rivers and Whychus Creek).
Most of the sockeye salmon choose the cold waters of the Metolius River to spawn, said PGE senior fisheries biologist Rebekah Burchell.
“Keep in mind we are still early in our reintroduction efforts,” she said. “The long term goal is restoring sustainable, harvestable salmon and steelhead runs, improving habitat, and enhancing water quality in the Deschutes.”
Just 36 sockeye were trapped by PGE, Oregon Department of Fish and Wildlife and Confederated Tribes of the Warm Springs Reservation biologists in 2015 and all were taken to the Round Butte Hatchery to be used for broodstock.
However, most of the fish (463) from the much larger run of 536 sockeye in 2016 were transported into the lake, she said. In 2017, 57 adult sockeye returned and were trapped and 18 were transported above the dam. The remaining were taken to the hatchery.
There was a record migration of sockeye and kokanee juveniles in 2017 with 440,000 of the juveniles captured at the utility’s selective water withdrawal tower and transported downstream. The previous high, Burchell said, was about 225,000 juveniles. Most of those are from kokanee that spawned in the Metolius River and that reared for a year in Lake Billy Chinook.
“So, we are expecting a large return of sockeye adults in 2019,” she said. “And, we’re expecting another large run of sockeye smolts this year.”
As co-owners of the hydro project, PGE and the Tribes work collaboratively to restore wild salmon and steelhead runs that were cut off when the dams for the project were built in the 1950s and 1960s.
In 2010, the two co-owners began operating a new fish passage system that allows juvenile salmon and steelhead to migrate downstream past the dams. The sockeye that return are based on an existing kokanee – land-locked sockeye – population in Lake Billy Chinook, the larger of two reservoirs backed up behind the two dams.
PGE’s effort to reintroduce salmon and steelhead into the Deschutes basin is not without its detractors. The Deschutes River Alliance sued PGE August 12, 2016 over what it says is more than 1,000 Clean Water Act violations in the river downstream of its complex of dams. That court case is ongoing in the U.S. District Court of Oregon.
DRA’s primary complaint is with the quality of water released from PGE’s dam into the 100 miles of Deschutes River downstream of the dams and the impact on the lower river environment. Those impacts, DRA says, are due to PGE’s 273-foot tall selective water withdrawal tower in Lake Billy Chinook, a surface attractor that helps juveniles find their way downstream to the dam where they are trapped, marked and transported below the dams. It is an integral part of the reintroduction efforts.
In addition to sockeye salmon, PGE and the Tribes have been reintroducing spring chinook and summer steelhead.
Many of the steelhead released into the lake will choose to head for the warmer waters of the Crooked River. In 2015 (the 2014-15 run), 93 steelhead were released into the lake, while 2,483 went to the hatchery. In 2016 (2015-16 run), 45 steelhead were released and 2,162 went to the hatchery and 30 steelhead were released and 2,068 went to the hatchery in 2016-17. Numbers of steelhead for the 2017-18 run are incomplete, but the tally so far is 1,304 fish.
In 2015, 957 spring chinook were taken to the hatchery to be used as broodstock, while 52 were released into the lake. The number used for broodstock dropped in 2016 to 721, but the number released into the lake rose to 54. Some 2,257 spring chinook were used as broodstock in 2017, with 20 released into the lake.
Burchell said that “although 2017 was a good run of Round Butte hatchery chinook, in the Columbia Basin, chinook numbers were down.”
The determination of which fish go to the hatchery and which fish are passed upstream is made by plans developed by ODFW and the Tribes, according to a May 2017 report (“2016 Adult Migration, Survival, and Spawning Test and Verification Annual Report”) by Burchell and colleague Megan Hill. The report says that “Known origin, upper basin adult Chinook and steelhead, as indicated by presence of an intact adipose fin with a left maxillary (LM) or right maxillary (RM) clip, were passed upstream of Round Butte Dam as specified in the plans ….” All others were returned to the hatchery as broodstock.
In essence, all of the adult steelhead and salmon that were taken to the hatchery for broodstock were raised as juveniles at the hatchery.
Of those released into the lake, the healthy salmon and steelhead are radio tagged so they can be tracked upstream of the dam. Nine fixed radio stations were set up in 2016, located at the upper end of the Deschutes, Crooked and Metolius river arms of Lake Billy Chinook, as well as at the confluence of the Deschutes with Whychus Creek, above the highway 97 bridge, at the mouth of McKay Creek and at Bridge 99 on the Metolius, the May report says. Two additional stations were located at Opal Cabin and at Opal Dam on the Crooked River at Opal Springs. Biologists also conduct mobile tracking surveys.
Of the 54 spring chinook that were trapped and transported upstream of the dam in 2016, 53 received radio tags. Of those, 25 “pinged” at the Crooked River arm and 7 passed Opal Springs, Burchell said. Five of the chinook chose to head up Wychus Creek where restoration work is in progress and 14 headed into the Metolius. About 20 chinook passed Opal Springs Dam in 2017 and 8 were detected above the dam. Seven were detected above the dam in 2016.
However, she said, there is a lot of intra-river movement where fish will travel briefly into one river only to turn and head for one of the other tributaries. “These numbers represent a snapshot of where the fish were when we detected them,” she said.
Steelhead are one year behind because they cover multiple years. Of the 45 steelhead that returned to the fish trap in 2015-16, 43 were radio-tagged. Some 30 were initially detected in the Crooked River and 17 passed Opal Springs. The fish mainly spawn in April, but turbidity early in the year make it nearly impossible to see redds.
Biologists survey for redband trout in Whychus Creek each year and in 2015-16 they came across two redds that were likely steelhead based on their size.
“We’re hoping that over time we will see even more steelhead and chinook redds in Wychus Creek,” Burchell said. “We’re still early in our efforts to have self-sustaining runs, but we’re happy with the direction we’re heading.”