Tracking Eulachon in the Elwha River

The Lower Elwha Klallam Tribe is learning more about the eulachon that keep showing up in the river, even more so since removal of the river’s two fish-blocking dams.

“Since 2005, we’ve been catching a handful of them in our outmigration rotary screw traps, but we aren’t sure if they are an ancient Elwha run or strays from the Fraser River in British Columbia,” said Rebecca Paradis, the Lower Elwha Klallam Tribe’s project biologist.

This distinct population of forage fish, also known as smelt, oolichan and candlefish, was thought to have been extinct by the 1970s. In 2010, the National Marine Fisheries Service listed the southern distinct population segment of eulachon (the population that resides in Washington, Oregon and California) as threatened under the Endangered Species Act.

For the next two years, with funding from a National Oceanic and Atmospheric Administration species recovery grant, the tribe will be sampling both larvae and adults from the Elwha, Lyre and Dungeness rivers for genetic and population studies.

The tribe is using plankton tow nets to catch adults and larvae, clam guns to collect sediment samples to find eggs, and observing possible spawning sites. So far, the tribe has found larvae in all three rivers, and adults in the Lyre.

“The state biologists and technicians at Jamestown told me they hadn’t seen eulachon in the Dungeness for years and didn’t think they were there anymore,” Paradis said. “They could be strays from another river system, but no other smelts are spawning that high in the river that we know of.”

Eulachon came into the river systems to spawn in March, at the time the coronavirus shut down most surveying operations. The tribe had to pivot and reconfigure its field team of several people to just one technician sampling weekly in the three rivers with a plankton tow net.

Similar to salmon, eulachon spawn in fresh water. A river’s current carries larvae out to the Strait of Juan de Fuca, where they develop into adults before swimming up river in late winter to spawn again, then die.

Eulachon is an important food source for both the tribe and salmon runs in the Elwha River.

The Elwha River is considered critical habitat for the southern population of eulachon, Paradis said. While there are no historic quantitative data, eulachon have been reported anecdotally to spawn in the Elwha River.

“Beyond that, we don’t know much about them such as their life history or their preferred habitat,” Paradis said. “The dams in the river likely negatively affected the species.”

For nearly 100 years, two hydroelectric dams on the Elwha River prevented salmon and other marine life from swimming upstream in the upper reaches of the river, where there is pristine spawning habitat.

However, after the dams were removed, the reconfiguring of sediment in the lower river may have helped improve spawning habitat for eulachon, Paradis said.

Lower Elwha Klallam Tribe natural resources technician Sonny Sampson samples a eulachon from the Elwha River in 2015. Photo: Lower Elwha Klallam Tribe