The humans outnumbered the Pacific Lamprey two to one Saturday, but no matter.
The Yakama Nation Fisheries released 50 adult lamprey collected last fall from the lower Columbia River in an outreach event that was equal parts cultural, environmental and educational.
Tribal leaders and fish biologists had plenty of company as curious families came out to investigate the eel-like species that emerged from the primordial muck 450 million years ago and has remained largely unchanged.
For the Yakamas, releasing lamprey in the upper Columbia Basin is an opportunity to bolster a threatened species that’s played a starring role in tribal history, and to shed misconceptions about a fish that looks fearsome but is relatively harmless, even to the species it feeds on.
Saturday’s release took place on a rocky stretch of shoreline upstream from the Prosser bridge, behind a church and the Les Schwab Tire Center.
Fisheries technician Sean Goudy said the lamprey was widely gathered by tribal forefathers, but no longer thanks to degraded habitat, passage and low numbers. Restoring lamprey numbers and repairing lost habitat isn’t just a tribal issue, he said.
“They’re a big part of that healthy ecosystem,” he said.
The Pacific Lamprey, or Asúm, is distinct from the reviled Sea Lamprey, an Atlantic variety that invaded the Great Lakes, damaged ecosystems and spawned eradication efforts.
Dave’y Lumley, a lamprey technician, said the lamprey is a “keystone” species for the Northwest. In its larval form, it inhabits the bottoms of rivers, filter feeding on whatever organic debris is at hand, cleaning the water.
After seven or eight years, it transforms into a snakelike creature with eyes and a suction disc. It makes for the ocean,where it lives a parasitic life, feeding on blood and bodily fluids of other ocean species, though generally not killing them.
Scientists estimate they spend two to three years in the ocean before returning, salmon-like to the river to breed. Females lay up to 100,000 eggs each.
Lamprey are endangered by many of the same conditions that affect salmon — water quality, predators, blocked passage and predation. Dams pose an even more significant hazard to lamprey than salmon: Fish ladders are designed to aid salmon through but the turning corners and flowing water tend to wash lamprey down.
Earlier this year, the Yakamas installed a lamprey-friendly wall at the Prosser dam to see if it helps move them up and downstream.
The tribal effort to boost lamprey populations is a high-tech business.
The Yakamas breed lamprey and also collect mature fish at the dams in the lower Columbia for redistribution to its upper reaches, including tributaries. The adults winter at a fishery, where scientists collect DNA information and tag them so that sensors embedded along the rivers can track their future movement.
Lumley dazzled visiting school children by allowing an adult about to be released to dangle from her hand, attached by small teeth and suction. To show how harmless the fish really is, she detached it from her hand and let it grasp her cheek.
The lamprey only feeds when it’s in salt water. The rest of the time it uses its ferocious-looking mouth to grasp onto rocks and the occasional human.
Her fearlessness emboldened children, who reached out to touch the slippery, unscaled creature before it slid down a small channel and into the river.
“Slimy” was the general verdict.
The release program is only a few years old, but fisheries experts say they’re encouraged that testing of juvenile fish indicates the released adults are successfully breeding in the river.
“The numbers are going up,” Lumley said.