Reintroduction of the eel

October 18, 2013 08:12 am

From left, Marina Cawley, Tod Sween and  Neal Espinosa electroshock in the Wallowa River looking for juvenile lamprey eels to see if  reintroduced adults successfully spawned. (KATY NESBITT/The Observer)
From left, Marina Cawley, Tod Sween and Neal Espinosa electroshock in the Wallowa River looking for juvenile lamprey eels to see if reintroduced adults successfully spawned. (KATY NESBITT/The Observer)

Lamprey eels show signs of successful spawning in Wallowa River 

MINAM — In a region where fish restoration affects everything from industry to recreation to tradition, collecting and analyzing data is crucial. This fall, Nez Perce Tribal Fisheries set out to see how well lamprey eel reintroduction is working in the Wallowa River.

In April of 2011, a team of biologists led by Elmer Crow of the Tribe’s Lapwai, Idaho, office released 40 adult lamprey at the confluence of the Wallowa and Minam rivers.

Crow, a Nez Perce Tribe member who drowned in the Snake River saving his grandson in July, led the reintroduction effort due to the lamprey’s role as a traditional food source. Their high fat and protein content made them an important meal for indigenous people.

Lampreys have received a lot of interest in recent years due to their dwindling numbers. An anadromous fish, lamprey spawn in freshwater where their offspring live for three to seven years, feeding on algae, before migrating to the ocean. 

They live in the ocean for one to three years, feeding on fish and marine mammals. In time, the adult lamprey, which range from 15 to 30 inches long, make their way back to their rearing waters to spawn. 

Fish passage along the dams of the Columbia and Snake rivers were built with salmon and steelhead in mind, but lamprey struggle to get over the ladders. 

 “They aren’t as strong of swimmers. They can’t make the right-angled edges over the ladders,” Tod Sween of the Nez Perce’s Lapwai office said.

At each of the eight dams, 50 percent of the lamprey swimming upstream don’t make it, Sween added. By the last dam, there aren’t many left. Jim Harbeck, Joseph field office supervisor, said in 2010 there were only 15 counted coming over the Lower Granite Dam on the Snake River.

A partnership between the Nez Perce and Umatilla tribes is working to trans-locate lamprey to the Wallowa in hopes they will spawn and create a native population, Harbeck said. The lampreys are wild, not from hatcheries, and were gathered at the John Day, The Dalles and the Bonneville dams’ fish ladders.

Crow led a second reintroduction in the spring of 2012. Sween, who worked closely with him for many years, is now taking the lead on the reintroduction.

“A lot of what we’re doing is a direct result of his passion for the lamprey eel,” Sween said. “So much of it is cutting edge, genetic stuff, along with the tribal relationship — knowing the fish were here historically.”

This fall, biologists set out to see if the released lamprey successfully spawned. Armed with nets and electroshocking devices, Sween joined up with members from the Joseph office to find, collect genetic samplings and measure juvenile lamprey. 

 “Tod asked if we could have some staff assist,” Harbeck said. “We are vitally interested in the results of the outplanting.”

Harbeck said he has spoken with a woman who grew up on Joseph Creek. “As a little girl she remembered the eels would swim in deep pools. They called them water snakes.”

Further proof that lamprey were once common to the region is the town of Asotin, Wash., on the Snake River. Asotin, Sween said, is an Anglified version of a Nez Perce word “Hesew” that means “Place of the Eel.”

The Tribe is one of many agencies working to restore endangered salmon and steelhead to the Columbia River Basin. 

“If we are going to have full salmon recovery in a drainage, we need to have a healthy ecosystem,” Sween said. “The watch doesn’t tick unless all the parts are there.”

Part of a healthy ecosystem, according to Sween, is restoring all of the species which were native to the basin’s drainages, including the lamprey.

Sween showed the other biologists the habitat lamprey prefer — mainly mud along the shore of the river, finely sorted sandy beaches and fine organic muck. Sween’s definition of the perfect “muck” is, “If it holds onto a boot.”

The venture was a success, with a handful of juvenile eel shocked, netted and measured before their release back into the sandy soil along the banks of the river.


“We electrofished three different reaches along multiple transects,” Harbeck said. 

One reach was just above the Minam/Wallowa boat ramp release site, one approximately halfway between the boat ramp and the Minam State Park and one just below the park, Harbeck said. 

“Although definitely not abundant, we did find juveniles in all three reaches,” he said. “We took genetic samples from these fish and will submit them for parentage analysis. That will confirm reproductive success.

“So, for now it does appear that reproduction occurred from the translocated adults released in 2012 and 2013. This mimics what the Nez Perce Tribe has found in other streams in Idaho. For us ‘fish heads’ it was a rare, but great day. After seeing those juvenile lamprey, I know Elmer Crow must be smiling. 

“Elmer was such a strong and passionate advocate for lamprey reintroduction and wanted to see ‘eels’ once again in the Wallowa country.”