Mitigating the migration
Amid the roar of the Northwest's largest waterfall, a simple shake of the head told the story.
It was an unseasonably brisk and sunless Monday morning, and representatives from the Confederated Tribes of Grand Ronde — a group of 27 affiliated tribes in Oregon — had arrived at the foot of Willamette Falls to take part in the annual Pacific lamprey harvest. The lamprey — a prehistoric, eel-like fish that sustained life in the earliest days of civilization by the falls — is still considered sacred to the tribes and is celebrated during an annual feast ceremony.
But first, the slippery creatures had to be caught. And on this particular morning, the harvesters came up empty when they first poked their heads beneath the falls and groped for lamprey hugging the damp rock walls with their sucker-like mouths. The fishers emerged with a shake of the head to the rest of the team and pressed on to the next hopeful spot.
The morning eventually ended with smiles, as the boat pulled back into its dock in Oregon City carrying several dozen lamprey. But the fruitless early stages of the search were a subtle reminder of why the tribes aren't just harvesting the lamprey — they're trying to save them.
Lamprey aren't listed as a protected or endangered species yet, but their numbers have dwindled amid changing habitats.
"It seems like on some of these species, no one will do anything until it gets listed," Grande Ronde Fish & Wildlife Program Manager Kelly Dirksen said. "And when it gets listed, it's generally a pretty dire case."
So while the lamprey caught most recently will be prepared as food, others taken at the falls this summer are being "translocated" to the water above Fall Creek Dam southeast of Eugene.
"Fall Creek Dam was built 50 or 60 years ago," said Torey Wakeland, an aquatic biologist with the tribes. "When the dam went in, the (lamprey) population extirpated ... they migrated out of the stream system. They've since modified the dam to allow for fish passage, so we're trying to reintroduce lamprey above the dam."
Lamprey use their mouths to crawl up rocks like those at Willamette Falls, but are unable to do so at dams in the absence of fish ladders.
Since the project began in 2014, the tribes have translocated 240 lamprey annually from the falls to the dam. The key is for the relocated adults to spawn juvenile lamprey at the dam, which can then attract others to return from the Pacific Ocean and spawn — thus reviving the ecosystem that existed before the dam was built.
"With adult Pacific lamprey, they actually hone in on the pheromones released by larval lamprey that are still living in the stream system," Wakeland said. "So essentially, they smell the juvenile lampreys that are still in fresh water and hone to those grounds."
To monitor such movements, the tribes also implant radio tags in 40 of the lamprey each year.
"We can see how they're moving up and down the stream system," Wakeland said. "The other 200 are just relocated so they can spawn and essentially die, and it leaves the system with juvenile lamprey."
Several years in, the effort appears to be paying off.
"Each year, the amount of juvenile lamprey up there is getting to be more and more, so we should start attracting adult Pacifics to migrate in there," Wakeland said. "This last year, we had some juvenile lamprey that were out-migrating to the Pacific Ocean come through Fall Creek Reservoir heading downstream, so we know they're able to live and mature up there. There's good habitat for them."
While lamprey don't have the revered status of other imperiled species like salmon or steelhead among the general public — Dirksen joked that they need a better public relations team — they're nonetheless a vital cog in the local ecosystem dating back to prehistoric times.
"If you care about steelhead or salmon, you should care about lamprey, because they will fill the belly of a sea lion just as fast," Dirksen said. "What all is dependent on this one species is going to be really hard to know. Until you remove it, it's hard to know who all is going to have issues."
For members of the tribes, the issue goes beyond raw science.
"(It's a) very culturally significant species to the tribe," Wakeland said. "It's appealing to know you're carrying on a tribal tradition. My dad has taken me lamprey fishing since I was young.
"We don't want to get to the point of being truly worried about the future of the species."
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