Fish return: Success comes one fish at a time
It's Friday, an overcast morning, and about 75 spring Chinook slap and swirl in coffee-colored water. They're captured in a holding pen at the base of the re-regulation dam below Pelton Dam.
These salmon are on their way from the ocean back to their spawning grounds, but the dam blocks their way.
A cadre of fish biologists stand at the ready to portage them around the dams to their home. First, they use the opportunity to examine the returning fish.
A gate rises to collect a group of fish in an elevator cage which then lifts them up to a second floor.
Here the fish slide into a tank of water spiked with a drug to calm them. One-by-one, Ryan Moon, the manager of the Round Butte Hatchery, grabs each fish and measures its length.
"Three-fifty," Moon calls to her colleague, Amber McEnaney. This tells McEnaney how much antibiotic to load into the two syringes she injects into the fish, this to prevent the spread of disease.
Meanwhile, Renny Schmidt rubs a sonogram wand along the belly of the fish looking for eggs. No eggs means it's a male. Eggs — female.
After the poke and the scan, the fish goes back into the watery cage destined for the hatchery.
This utterly unnatural process has replaced natural fish passage.
The end of natural fish passage
Natural fish passage ended when PGE completed the dam complex with the Round Butte Dam in 1964. The three-mile fish ladder — at the time the longest in the world — worked for returning salmon but not the sea-going juveniles. The system had a collector for the young fish, but confusing currents in Lake Billy Chinook meant juvenile fish couldn't find the collector, and lost their path to the ocean.
For 50 years — half a century — fish could not return to their spawning grounds in the tributaries of Lake Billy Chinook.
Portland General Electric built the Round Butte Fish Hatchery in 1972. The Oregon Department of Fish and Wildlife operates the hatchery to provide a fishery for Chinook and steelhead in the lower Deschutes River to make up for the loss of habitat upstream of Lake Billy Chinook.
Yet juveniles in Lake Billy Chinook still could not find their way to the ocean.
In 2001 the Confederated Tribes of Warm Springs bought part ownership of the Pelton Dam complex, motivated in part to restore the fish to the basin.
"The Tribes are a huge driver in bringing these fish back," said Megan Hill, the fish biologist who manages the Natural Resources Group at the Pelton Round Butte Project.
In 2010, PGE and CTWS built the $100-million Selective Water Withdrawal Tower above the Round Butte Dam.
The tower now allows biologists to capture the juvenile smolt, carry them below the re-regulating dam and release them for their journey to the ocean.
Which leads us to the magic moment on that misty Friday morning.
One came back.
As the team processed hatchery fish after hatchery fish, identified by the clipped adipose fin, Moon finally held the prize in her hands. This fish had a clipped maxillary fin, which means a reintroduced spring chinook made it to the ocean, spent about two years there, and has returned.
This fish represents success. The reintroduction program worked for her. With a lift from humankind, she will complete the full-cycle journey to the ocean and return to spawn in the tributary where she grew up.
Schmidt inserted a radio tag to the reintroduced fish. Now the team will know which tributary she chooses, where she spawns.
For now, at least, this is as natural as this journey will get for salmon in the upper Deschutes Basin.
"It brings fish back to a place where fish have been extirpated, or locally extinct," said Hill, "We're returning a piece of the ecosystem that had been there for thousands of years."
Three dams block fish passage for salmon on this part of the Deschutes. Fish swimming downstream to the ocean must passRound Butte Dam, which creates Lake Billy Chinook, then Pelton Dam with creates Lake Simtustus, and finally the re-regulating dam.
The Round Butte Hatchery lies at the base of the Round Butte Dam. The hatchery stock originates from wild Deschutes fish.
The hatchery puts some fish in Lake Simtustus for the recreational fishery, and stocks the tributaries of Lake Billy Chinook with fish they hope to repopulate the spawning grounds.
About two years after hatching, the fish begin to smolt. They grow silvery scales and their bodies start to change so they can acclimate to salt water. As they head to the ocean, the Selective Water Withdrawal Tower creates currents which guide them into the collection facility.
Of 100,000 fish stocked into the tributaries each year, the system collects about 25,000, transports them below the re-regulating dam, and releases them on their swim to the Pacific.
Since the first reintroduced chinook returned in 2012, about 375 have returned.
In purely mathematical terms, 375 returning fish — out of hundreds of thousands collected — seems small.
Hill defines success differently.
"Fish are spawning in a habitat where they weren't able to for 50 years," said Hill,who has been with the program since before the first fish returned. "I think it's a success, but we're not happy with these numbers."
Hill would like to see more sustainable, harvestable runs. The program's goal is to see a thousand fish per species return each year.
"Typical of historic runs," said Hill, "what the habitat can support in the upper basin."
Current efforts to improve fish runs focus on the juvenile fish, and starts with introducing them to their spawning grounds.
Erik Moberly with the Oregon Department of Fish and Wildlife builds ponds for the young salmon to hold the smolts in the stream long enough for the signature of the water to imprint on these small fish.
"Enough research shows this helps get adults coming back," said Moberly.
The cormorants perched on the booms signal concern of predation. The team has learned releasing the juveniles at night increases their survival rate, possibly because the predators can't see them.
For each step the team takes to to improve the chances for the fish, they need to wait two years when that batch of juveniles returns as adults to calculate the impact of their efforts.
The process involves patience, perseverance, and a core belief that what they're doing matters.
The dams generate enough electricity to power 150,000 homes.
"We're using a public resource," said Hill, "and with that comes the responsibility to protect that resource."
*2022 run is incomplete, many more fish will return in June.
Since the reintroduction project began in 2012, few fish have made the round trip to the ocean and back to their spawning grounds in the tributaries of Lake Billy Chinook.
The fact that some have returned proves the system works.
Biologists want to increase those numbers.
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