How lamprey get over Bonneville Dam

OPB Ecotrope
By Cassandra Profita
June 21, 2012

Awhile back, I shared a video on Facebook of the relatively new lamprey passage system at Bonneville Dam taken by Columbia River Intertribal Fish Commission President Paul Lumley on his iPhone. “Cool!” I thought. “I didn’t know Bonneville had a lamprey passage system!”

One of my followers commented that the video could use some narration. So, I got Sara Thompson of CRTFC to talk about lamprey and the passage system and cobbled the video together with her voice and photos in the piece above.

Then I found out that Oregon Field Guide had done this, much more sophisticated television piece about the exact same topic:

The message is basically the same in both videos: The eel-like lamprey have been on a mysterious and rapid decline over the last decade. The number of lamprey counted at Bonneville Dam dropped by 80 percent from 2002 to 2010.

The lamprey passage system serves the same purpose as the fish ladders that help salmon get over Bonneville. Like salmon and steelhead, lamprey are anadromous. They spend a big chunk of their lives at sea and return to rivers to spawn. To reach many of the tributaries in the Columbia River Basin, they need to get up and over Bonneville Dam.

But lamprey don’t swim like salmon and steelhead. They cling to surfaces with their giant sucker mouths and propel themselves forward like snakes. They can’t traverse sharp corners, so they have a harder time getting up the existing fish ladders.

“It doesn’t matter if the obstruction is a foot tall or 150 feet tall,” said Lumley. “It just takes one little corner and it can block them – it could be smaller structures for irrigation diversions.”

The lamprey passage system is one of many ways the tribes that harvest lamprey are hoping to restore dwindling populations.
Lumley says habitat destruction, obstructions such as dams, culverts and tide gates and warm or contaminated water could all be contributing to the lamprey decline.

“These species have been around for 400 million years and have survived four major worldwide extinction events over time,” he said. “And here we are now. They’re disapearing because of man.”

The tribes have proposed redesigning other dams and structures, restoring lamprey habitat, improving water quality and even starting lamprey hatcheries in their lamprey restoration plan.

But the key might be simply studying lamprey behavior.

“We still have very little understanding of their life history,” Lumley said.

This week, the U.S. Fish and Wildlife Service and the Columbia River Intertribal Fish Commission hosted the third Lamprey Summit since 2004 to encourage government agencies, tribes and other interested parties to talk about the status of lamprey and how to improve their numbers.

Many at the Summit even signed an agreement to protect and restore lamprey.

“What we’re trying to do is bring a stronger sense of on-the-ground commitments,” Lumley told me this morning. “Even though we’ve had these summits in the past, the lamprey continue to decline.”

Tribes were once able to harvest lamprey at numerous sites throughout the Columbia River Basin. Now they’re down to just one site: Willamette Falls.

“We used to have millions,” Lumley said. “There are stories about how Celilo Falls were black because they were covered in lamprey. Willamette Falls had a tremendous amount of lamprey, that was just a subset.”

In 2003, four lamprey species were petitioned for listing under the Endangered Species Act. That would give them the same status as the salmon and steelhead the federal hydropower system operators are spending so much time and money to restore. The U.S. Fish and Wildlife Service found lamprey populations to be declining throughout the West Coast, but the agency said it didn’t have enough information to move forward with an endangered species review.

The agency has since launched a Lamprey Conservation Initiative to improve the species’ status, and it was one of many entities that signed a Lamprey Conservation Agreement on Wednesday.

But not all the tribes in the Northwest signed the agreement. The Nez Perce, for example, are still debating whether to sign on.

Lumley said some of the tribes are “nervous” about signing an agreement without specific commitments to actions that would restore lamprey.

“We’re not quite sure why the Fish and Wildlife Service hasn’t listed them yet,” he said. “I believe this conservation agreement is an effort to try to get commitment to avoid a listing.”

Original source