How Pacific Lamprey Could Help Nourish Streams

Jul 26, 2013

Pacific lamprey are toothy eels that were once plentiful in the Northwest. Many considered them trash fish, but they are an important staple to Native American diets and ceremonies. Lamprey numbers have greatly declined in the past few decades. Now there is a push to understand more about the eels, so more can be harvested for tribal tables.

Eva Carl with a dead Pacific Lamprey eel, which has been attracting the attention macro-invertebrates to Northwest Streams. These macro-invertebrates are essential to algae growth in the stream, which will help keep the creeks healthy.
Credit Courtney Flatt

Water pours off the top of Willamette Falls. Yakama Nation member Rod Begay reaches his hand inside the falls and plucks a foot-and-a-half long eel out of the water.

He tosses the Pacific lamprey into a soaking wet burlap sack. A dozen other eels squirm inside.

Begay will take the lamprey he catches back to Yakama Nation tribal elders. He estimates the tribal fishing team caught 500 of the toothy eels on this morning.

Brian McIlraith helped collect the eels at Willamette Falls, near Oregon City, Oregon. He studies lamprey for the Columbia River Intertribal Fish Commission.

McIlraith: “When you’re harvesting lamprey they are in the watery cracks and crevasses, and they kind of get formed in these watery pockets. You just have to go in there and grab them. Some of them are climbing up the rocks. Some of them are deep down underneath the water.”

The Pacific lamprey making their way up Willamette Falls are the last harvestable population in the Northwest. That’s why Begay and other Yakama Nation fishers have driven three hours to catch the eels. Lamprey numbers have dropped dramatically in the past 25 years. No one is sure exactly what happened.

If these lamprey kept traveling upriver, they would overwinter in tributaries. Once springtime rolls around, they would build a rocky bed, where they would lay their eggs and die.

Relatively little is known about Pacific lamprey. That’s why it’s taking more field work to understand how lamprey impact rivers and streams.

In central Washington, Yakama Nation member Eva Carl wades out into the middle of Upper Toppenish Creek. She’s trying to figure out how lamprey bodies might act as fertilizer for streams.

Earlier in the season Carl placed netted bags filled with spawned out lamprey in this creek. It’s a typical creek where lamprey might spawn and die.

She’s been monitoring stream flow and taking water quality samples every three days.

Carl picks up one of the lamprey bodies.

Carl: “It’s just the head left. We had a flow tag to identify which fish.”

Over the weeks, the rotten lamprey smell has attracted a few predators to the creekbed. The inch-and-a-half-thick eels now look like a shoelace sitting at the bottom of the creek.

Carl says all summer long these eels have been drawing interest from large mammals like bears, as well as providing food for small insects, which she refers to as macro-invertebrates.

Carl says that helps keep creeks healthy.

Carl: “Without our macro-invertebrates in our streams, it will cause more algae growth.”

Many studies like this have been conducted with salmon. The Oregon Department of Fish and Wildlife has a program that places salmon carcasses into streams throughout the state.

Karen Hans is one of the program’s biologists in the Willamette Valley.

Hans: “It’s essential to the river ecology. The salmons’ bodies are rich in proteins, in fats.”

Hans says the same thing would be true for Pacific lamprey. The eels also store proteins and nutrients from the ocean that Hans says are so important to stream ecosystems.

While Oregon’s salmon study has been going on for years, this lamprey carcass study is thought to be the first of its kind in the Northwest.

Emily Washines works with Yakama Nation fisheries. She’s also member of the tribe. She says salmon and lamprey have been next to each other on ceremonial tables for as long as she can remember.

Washines: “Our elders say one cannot exist without the other. They both need to benefit side-by-side. That’s one of the reasons that we’re so excited about the biological research going on now is because it’s trying to parallel what’s been going on with salmon for decades.”

Washines’ tribe is going to continue monitoring the ecosystem the rest of this year. So far, researchers say, the creek’s health is improving. If that continues it will provide better habitat for the species that live there. And some day, the tribe hopes, that will include the Pacific lamprey.

Copyright 2013 Northwest Public Radio