Chris Gregersen injects a young chinook salmon with a small transponder used for tracking the migration of the fish. Photo courtesy of King County

Chris Gregersen injects a young chinook salmon with a small transponder used for tracking the migration of the fish. Photo courtesy of King County

King County scientists work to save chinook salmon

They conducted a study to determine how the salmon use the Green River as a habitat.

Scientists with the King County Department of Natural Resources and Parks are using technology to save the endangered chinook salmon in the Green River.

The project began near Auburn, where scientists with the county set up a fish trap in the river to collect young chinook salmon. Once collected, the scientists injected a small transponder with a unique number in each fish and released them back into the river.

Downstream in Tukwila, the scientists set up a receiver antenna that records when each salmon passes through. Using these tools, the scientists determined how long it takes the young salmon to swim downstream, and thus how important the lower section of the river is to their survival.

By tracking the migration of young chinook salmon, scientists hoped to better understand how to effectively restore their habitat, according to King County.

“We have a longstanding commitment to protect and restore chinook salmon habitat to help recover depressed populations,” said Chris Gregersen, a fish ecologist with the King County Department of Natural Resources. “With this research, we can help identify where these fish are actually going to be living and help us tailor our restoration projects to have the most benefit.”

The data from this study completely changed the understanding of chinook salmon in the Green River, according to King County.

Previously, scientists who studied the fish believed the salmon moved through the lower part of the river rather quickly, according to King County. The study proved the opposite to be true. The lower part of the Green River is actually extremely important to the survival of the young chinook. Some of the salmon spent as long as two months in the lower part of the river before traveling downstream to Tukwila, according to King County.

“We found this spring that the smaller the fish, the more time they spent in the lower Green,” Gregersen said. “The larger fish tend to move through really quickly. The smaller fish tend to stick around for upwards of two months.”

As the fish grow, their habitat needs change. For example, really young salmon need shallow, slow-moving water protected from predators. As they get bigger, they can venture out into the open river, Gregersen said. Now that the scientists know what size salmon stay in the lower Green River, they can tailor the restoration projects to match the specific needs of the smaller salmon, Gregersen said.

Restoring the lower Green River will help with efforts to recover the chinook salmon populations, which have been decimated by the effects of climate change and overfishing, according to the National Wildlife Federation. In fact, the population of chinook salmon has decreased by 60% since salmon population tracking began in 1984, according to the Environmental Protection Agency.

River restoration projects have been shown to improve the ecosystem and long-term outlook for salmon, according to Puget Sound info. This study armed King County scientists with the knowledge needed to effectively restore the river.


In consideration of how we voice our opinions in the modern world, we’ve closed comments on our websites. We value the opinions of our readers and we encourage you to keep the conversation going.

Please feel free to share your story tips by emailing editor@redmond-reporter.com.

To share your opinion for publication, submit a letter through our website https://www.redmond-reporter.com/submit-letter/. Include your name, address and daytime phone number. (We’ll only publish your name and hometown.) We reserve the right to edit letters, but if you keep yours to 300 words or less, we won’t ask you to shorten it.

More in News

Teaser
King County approves emergency grant after U.S. Supreme Court overturns Roe v. Wade

Washington is expecting an influx of people seeking abortions from out of state.

Fedor Osipov, 15, flips into Steel Lake in Federal Way during last year's heatwave on June 28, 2021. Olivia Sullivan/Sound Publishing
Heatwave expected to hit King County

Temperatures will likely reach 90 degrees Fahrenheit on Sunday, June 26, and Monday, June 27.

Judged by XII: A King County Local Dive podcast. The hands shown here belong to Auburn Police Officer Jeffrey Nelson, who has been charged with homicide in the 2019 death of Jesse Sarey.
JUDGED BY XII: Examining Auburn police officer’s grim tattoos

Episode 5 in special podcast series that explores Jeffrey Nelson’s role in the death of Jesse Sarey.

Derby Days. Courtesy of Experience Redmond.
Mark your calendars for Redmond’s annual Derby Days celebration

Attendees should expect two days of action-packed fun from July 8-9.

File photo.
Former Bellevue teacher sentenced in federal court over child pornography

Department of Justice says the man had 1,764 images of child sexual abuse in his possession.

Photo courtesy of King County.
Officials urge caution when swimming this summer

Cold spring temperatures and larger than normal snowpack have created dangerous conditions

File photo.
Bellevue man charged in 2019 assault that left a man dead on a Redmond roadway

After a two-year investigation, Bradley Hibbard was arrested for murder in the second degree.

File photo
Fireworks ban takes effect this year in unincorporated King County

The new law does not extend to cities, which each have their own regulations around fireworks.

Vanesha Hari. Courtesy of Workforce Career Readiness.
Redmond High School student receives national recognition for excellence

From a young age, Vanesha Hari wanted to leave the world in a better place than she found it.

Most Read