Columbia River: As efforts help salmon rebound, lampreys are in danger of becoming a thing of the past
By Ben Pittman-Polletta
At the north side of the Bonneville Dam spillway, what looks like a ventilation duct zigzags out of the Columbia River and climbs up and over the concrete dam. Red placards along the hinged top read: “Do Not Lift.” If you disobey those signs at the right time of night, you might see a scaleless gray fish sucking and wriggling its way to spawning grounds.
Lamprey. It swims with salmon up and down the Columbia River during its life cycle, but it’s uglier, older, slower and not as popular as chinook or sockeye or even steelhead.
And its numbers are plummeting –fast.
The snaking duct, built last year, is one of three lamprey passage systems at Bonneville –lamprey ramps for short. It’s part of the intense efforts going toward saving lampreys.
Precious few adult lampreys have climbed the new ramp: a record low 8,622 last summer and about the same number this summer.
As late as the 1960s, more than 400,000 lampreys swam up the Columbia each summer. A steady decline since then became wild swings in the past decade. In 2003, 117,000 lampreys passed over the dam; in 2008, only about 14,000 did. The speed of the drop startles even biologists.
“We’re all kind of scratching our heads. We know salmon are doing so well,” says Bob Heineth, a fish biologist with the Columbia River Inter-Tribal Fish Commission who has watched endangered salmon numbers rebound in the past few years. “Why aren’t the lamprey doing as well?”
Lampreys –with no commercial fishery and little sex appeal –have long struggled for specific attention and funding. Some steps taken to help salmon, from fish ladders that lampreys can’t climb to turbine screens that catch juvenile lampreys, haven’t been kind to the lamprey.
In 2008, the Yakama, Colville, Umatilla and Warm Springs tribes, with government agencies including the Bonneville Power Administration and the U.S. Army Corps of Engineers, agreed to plans for operation of Columbia and Snake River dams. That 10-year, $900 million agreement to improve fish passage also pledged that tribes would not advocate breaching dams or listing the Pacific lamprey as endangered.
But also over that time, the Corps of Engineers and BPA will spend about $70 million to specifically improve lamprey passage.
And they are going to need it.
The ancient fish
Lampreys have roamed the oceans for 360 million years, compared with salmon’s 6 million years. The lamprey’s life cycle is even more unusual than the salmon’s. Its eggs hatch into wormlike larvae, which spend up to six years feeding in the muddy bottoms of streams and rivers. Larvae metamorphose into adults, then are swept into the ocean where they spend up to three years, leached onto and sucking the blood of larger fish.
Biologists believe lampreys return upriver and follow the smell of their larvae to find a spawning ground, instead of returning to the stream where they were born. Slower, weaker swimmers than salmon, they use their mouths and eel-like bodies to work their way up cracks and crevices in the rocks beneath slow-moving waters.
“These creatures are amazing,” says John Zauner, hydropower coordinator for Willamette Falls. “They’re following little channels of water, wiggling and sucking their way up.”
Lampreys have food, medicinal and ceremonial purposes for many Northwest tribes. The Umatilla use the fish oil to cure earaches and wrap wounds with the fish skin. “You can always see lamprey, when they’re available, as a food at the longhouse,” says Aaron Jackson of the Umatilla tribe. “Some tribal members, they just love them.”
But its strong flavor and oily texture make it an acquired taste, he says. “A little bit goes a long way.”
They’ve never had the cachet and status of salmon. But their function is just as important. Lamprey larvae clean the riverbed, burrowing into the mud and filtering out algae, small organisms and waste as food. Fattier and easier to catch than salmon, lampreys also provide meals to many fish and marine mammals.
“Sea lions and seals really like lamprey,” Jackson says. “But if they’re not there, guess what they’re going to focus on: salmon.”
Fixing the problem
Widely thought of as trash fish or sturgeon bait, lampreys in the Umatilla River were eradicated with pesticide in the 1970s as an effort to protect salmon. That image had turned around by the 1990s, and in 2003 a petition was filed to list the lamprey as an endangered species.
Structural changes on dams have trickled into place to help the fish as the lamprey began its nosedive. Efforts have focused on passage of adult and juvenile lampreys. Lamprey-friendly ramps have been placed at Bonneville Dam and Willamette Falls in Oregon City and at Three-Mile Falls Dam. The Corps of Engineers completely redesigned a fish ladder at John Day Dam to suit both salmon and lampreys. And the Umatilla River has been repopulated by transporting adult lampreys to their spawning grounds.
“We’ve never done this before, and it’s kind of an adaptive process,” says Zauner of Willamette Falls.
Lamprey-restoration efforts are limited by the presence of endangered salmon. Anything done to help lampreys cannot harm salmon. So fish ladders need to be redesigned to benefit both lampreys and salmon, or at the very least, they can improve passage for lampreys without disturbing salmon passage. Lampreys are notoriously poor swimmers and have a tough time climbing fish ladders designed for salmon –which means virtually every fish ladder in the Northwest.
All the efforts are trial and error because lampreys are little-studied. Some of the BPA funding will go to research.
What worries biologists who work with lampreys most are those unknowns.
“There’s other things going on that we don’t have a very good handle on,” Heineth says. “Maybe the prey base for adult lamprey is down. Unfortunately, we just don’t have the resources necessary to start doing tagging and other ocean studies on lamprey like we really need to do.”
David Close, a lamprey biologist and member of the Umatilla tribe, points to the smaller dams all along the Columbia River as a problem, too. “There’s a lot of dams out there,” he says. “Not just the big ones that everybody’s pointing their fingers at. Hundreds and hundreds of dams.”
Then there are systemwide questions about the ecosystem, says Steve Mashuda, an attorney for Earthjustice, which advocates breaching dams or alternatives such as larger and more frequent water spills over the dams.
“It’s not rocket science, how to save these fish,” he says. “It’s political science. It’s managing the river to get it to flow more like a river.”
Ben Pittman-Polletta: 503-294-5079; email@example.com