DRYDEN — Pinkie-length, dark, worm-like things wiggle up from the sediment of the Wenatchee River at a local swimming hole in Dryden.

Tyler Beal uses a electrofishing machine to stun and scoop up a lamprey and deposit it into a net held by Dave’y Lumley. Beal and Lumley are both Yakama Nation fish biologists. Nearby, families in swimsuits watch the two scientists in waders and Beal with a large metal box strapped to his back.

One person exclaims that they can’t believe those creatures were in the dirt the entire time. A second asks if they bite.

Pacific lamprey larvae don’t bite, Lumley says. They’re not parasitic until they transform into smolts and go out into the ocean, and they won’t attach to humans. As larvae they eat debris and dead plant material on the bottoms of rivers and streams and actually help clean the ecosystem.

“As juveniles, they help turn the sediment and they eat organic matter so it helps keep areas healthier so you don’t get the large buildup of bacteria,” Lumley said.

Lamprey are an important part of the ecosystem, she said. They are anadromous, meaning they head out to the ocean as adults and return to rivers and streams to spawn.

They are also an important source of food for lots of animals and take the pressure off of salmon, Lumley said. They also die after spawning and their bodies deposit nutrients acquired from the ocean in local waterways.

The electrofishing is part of a lamprey survey Beal and Lumley are doing in the Wenatchee River. The Yakama Nation had been doing surveys every other year since 2012, but they started doing it yearly in 2016 after beginning a relocation project.

The two scientists survey a 50-meter reach of sediment and record the number of larval lamprey they find. The scientists measure the success of the lamprey by their density and by the quality of habitat they occupy.

Lamprey have been removed from some of the streams and rivers along the Wenatchee River for several decades, particularly above Tumwater Dam, she said.

The tribe is trying to bring back lamprey and so it is releasing adults that will give birth in the hopes that lamprey larvae will attract more adults to return, Lumley said.

“Lamprey don’t home like salmon do,” she said. “They don’t go to the same spot. It is thought it is a more geographical return. So like Columbia River fish come back to the Columbia River.”

In April, The Wenatchee World reported on the Yakama Nation lamprey relocation project in Tumwater Canyon. Students from Beaver Valley School helped at that time, picking up the almost foot-long adults and squeamishly depositing the wiggling, rope-like fish into the river.

The number of lamprey above Tumwater Dam has increased since relocation started, said Ralph Lampman, Yakama Nation project biologist. In 2016, zero lamprey were making it past Tumwater Dam. Now that number has increased to between 10 to 20 a year.

Their survey results of larvae in the upper Wenatchee River, such as Nason Creek, have also increased from zero lamprey per-square-meter in 2015 to four or five lamprey per-square-meter in 2018, Lampman said. The number of lamprey in the lower Wenatchee River, such as around Dryden, has been consistent since 2012 at about seven to 12 lamprey per square meter.

Scientists believe that lamprey larvae release pheromones that attract adults to spawn in those areas, he said. Releasing adults that then give birth increases the amount of larvae releasing pheromones downstream, which may attract more adults.

It is a challenge because, unlike rivers and streams in the lower Columbia River, the Wenatchee River is lacking in resident lamprey, Lampman said.

Resident lamprey are species that don’t go out to the ocean as adults, he said. Unlike Pacific lamprey, which as adults get close to a foot in size, resident lamprey stay small and can head upstream to spawn.

It is thought that the more resident lamprey there are in a river and stream, the more likely it is for adult lamprey to go to that area, Lampman said.

At the end of the day, though, Lampman and his coworkers enjoy working with lamprey, he said. These creatures get a bad rap because of their long, slick bodies and the prominent teeth. They also get confused with sea lamprey, which are a different, invasive species in the Great Lakes.

“Beauty is in the eye of the beholder,” he said. “We think they are pretty cute and cuddly, but some people just don’t see it that way. People see that big picture of that mouth and they get kind of put off by it. But if you really handle the adults or larvae you’ll see a really timid creature that wants to hide.”