This article was published on: 10/22/10 12:00 AM
Dam bypass is working, but what’s next for fish?
By Kate Ramsayer / The Bulletin
Published: October 21. 2010 4:00AM PST
This year, about 100,000 chinook, sockeye and steelhead swam into the large fish collection facility at Round Butte Dam on Lake Billy Chinook.
Biologists sorted and measured the young fish, then trucked them around three dams and released them into the Lower Deschutes, where they’ll continue their migration down to the Columbia River and out to the Pacific Ocean.
“We’re just elated with all these numbers,” said Don Ratliff, senior aquatic biologist with Portland General Electric, which co-owns the Pelton Round Butte complex with the Confederated Tribes of Warm Springs.
After more than a decade of planning, and a significant setback in 2009 when the $100 million-plus fish passage facility tower snapped during construction, those involved in the effort to bring back runs of salmon and steelhead to the Upper Deschutes and Crooked River basins said they are encouraged by the number of fish making their way to the facility.
Now, however, biologists are debating what to do with the salmon and steelhead once they return to the Deschutes River. Some are worried the returning fish will bring new diseases with them that could harm existing fish populations in the upper stretches of the river.
And after anglers grew concerned over warm water and fewer steelhead on the Lower Deschutes this summer, officials with the Pelton project began refining the mix of warm and cold water released from the dam, to bring the river temperatures closer to their natural range.
Early results are encouraging
This year, the fish passage facility collected about 42,000 spring chinook salmon, about 7,800 steelhead and about 50,000 kokanee, Ratliff said. Kokanee are the same species as sockeye salmon, except that kokanee stick to freshwater while sockeye migrate to the ocean. Biologists hope that by moving kokanee past the dam, their ocean-going instincts will kick in, and they will become sockeye — a theory they’re testing now.
While the numbers of chinook and sockeye caught were promising, Ratliff said that he was a little disappointed with the number of steelhead collected at the dam. However, those figures could pick up next year as the layers of warm and cold water in the reservoir settle into a natural pattern, he said, and it gets easier for the fish to find their way to the passage facility.
“We expect to have significantly better reservoir conditions next year than we did this year,” he said. “It will be easier next year than it was this year.”
Biologists’ goal is to see half of all the fish entering the reservoir make it to the facility at Round Butte Dam.
“I was very encouraged by the results they’ve had the first year,” said Mike Gauvin, Pelton mitigation coordinator with the Oregon Department of Fish and Wildlife.
Plus, the fish that did reach the collection facility were generally healthy, he said, with few injuries or fatalities as fish went through the facility.
PGE and the Warm Springs Tribes are required to do the fish reintroduction project as a part of their federal relicensing agreement for the Round Butte Dam. The Round Butte, Pelton and Reregulating dams blocked the path of migrating fish on the Deschutes River about 50 years ago, and early efforts at fish passage were unsuccessful. But the long-term goals of the current project are to have 1,000 steelhead, 1,000 chinook and 1,000 sockeye return each year.
Hatching a plan for returning fish
The fish biologists involved in the project are now starting to talk about what to do when the first batches of fish return, Gauvin said.
A handful of fish might return next fall, but for the most part the ones that left for the ocean this year are expected back in 2012. And even then, it would be considered a good year if 1 percent survive the trip to the ocean and back, Gauvin said.
“Nobody knows until it actually happens how many of the adults are going to come back,” he said.
The fish that do make it back, however, are very valuable, he said — they’re the strong ones that can evade predators, find food and survive trips around the dams.
So if only a few fish come back, it might be best to keep those fish in a hatchery to breed and pass those good genes down to the next generation, which biologists could then release upstream, he said. If only 20 or 30 fish are swimming around the Upper Deschutes and Crooked River waterways, it could be hard for them to find each other to spawn.
Also, he said, there’s a risk that if the returning adult fish are released upstream, they could bring diseases with them that they picked up in the Columbia River or the ocean, including whirling disease. One disease, caused by a parasite that attacks the head and spine cartilage of trout and salmon, can be fatal and can cause fish to whirl around, making them vulnerable to predators.
“One of the big things we’re concerned about, by introducing diseases above the project that aren’t currently there, that could have a drastic impact on native fish,” Gauvin said.
But Ratliff said that biologists already have been studying the diseases for years, and that it would be disappointing to not move fish upstream if enough return.
“We’ve been working at this for a long time, and if we get many back, we sure want to put them up above (the dam),” he said.
Biologists will continue to talk about the issue, he said, and probably come up with an answer next year.
Mixing cold and warm water
Project officials are also addressing the mix of warm and cold water that will be released from the dam over the course of a year.
The new facility at Round Butte Dam can take up cold water from the bottom of the reservoir, warmer water from the top of the reservoir, or a mix of the two and send it downstream, affecting the Lower Deschutes flows.
Previously, the dam only took water from close to the bottom of the reservoir, disturbing the natural cycle of water temperatures, Ratliff said — now, the goal is to have the water temperatures go back to what they would be if the dams and reservoir weren’t there.
This summer, the water released was warmer than it should be early in the summer, upsetting some anglers downstream. But Ratliff said the correct mix of temperatures should be in place for next year.
“By July of 2011, then the reservoir should be set up the way it will be from now on at that point in the year,” he said, “and we’ll have more cold water.”
Making the whole system work will take some refinement, said Jim Manion, manager of Warm Springs Power and Water Enterprises.
“But for the first year, all in all we’re very pleased with how it’s operating,” he said.
The change in temperatures did cause a bit of an uproar in the steelheading community this summer, said Matt Shinderman, a fishing guide and natural resources instructor at Central Oregon Community College. But overall, it was an average year for steelhead on the Lower Deschutes.
“Steelheading, particulary from a guiding perspective, it’s always a variable thing,” he said. “Some years are going to be better than others.”
By nature, anglers are optimistic, said Dave Merrick, manager of Fly and Field Outfitters in Bend. He thinks the ability to control the temperature, and help cool down the lower reaches of the river at certain times, will be a good thing in the years to come.
“That should be an advantage to us — and the fish, most importantly,” Merrick said.
Kate Ramsayer can be reached at 541-617-7811 or firstname.lastname@example.org.
Published Daily in Bend Oregon by Western Communications, Inc. © 2010