Emergency action ordered as iconic Eastside salmon species nears extinction
Folks living on the Eastside are likely aware of kokanee salmon — the red variety of fish unique to Lake Sammamish. You learn about them growing up in the area, going to Salmon Days and visiting the Issaquah hatchery. This is the salmon that sticks around all year long. It’s like a member of the community.
But that awareness may soon fade as Lake Sammamish’s remaining kokanee are suddenly closer to extinction than ever (two other varieties are already extinct). The last count yielded 20 such salmon in Lake Sammamish during their run — when they spawn. It’s barely a drop in the lake compared to five years ago when 18,000 kokanee were counted.
“The native kokanee salmon – important to our history, our culture, our environment – are facing new challenges that potentially threaten their very existence,” said King County Executive Dow Constantine. “Together with our partners, we will take new, immediate actions to protect the iconic species and continue our long-term work to create healthier salmon habitats throughout our region.”
County biologists are now tasked with studying the unexpected problem to determine what is causing the species to disappear. Parasites, bacteria, and other diseases are suspects. But a likely factor is the increase in high temperatures throughout the year. Recent years have been warmer, with hotter streaks. This warms the water and lowers oxygen levels for the fish.
The sharp decline comes a few years after the county formed a special work group in 2007 to support the salmon and took measures to increase their population. That group is recommending immediate actions to address the emergency.
- Trap the salmon for breeding at local hatcheries.
- Use latest technology to save the unique genetic structure of Lake Sammamish kokanee
- Release more young salmon into the lake in the fall of 2019 after water temperatures cool and oxygen levels rise.
- Reintroduce kokanee to more area streams and creeks in the watershed. This will hopefully help maintain fish populations should one creek fail.
- Study the issue to provide strategic action to address underlying factors.
Kokanee are a bit different than sea-going salmon. They’re a variety of sockeye salmon, but unlike those that are born in freshwater and spend their lives in saltwater, kokanee live entirely in freshwater. That makes the salmon in Lake Sammamish unique.
According to county officials, local kokanee have a specific genetic signature; they’ve adapted to Lake Sammamish and its surrounding streams. They cannot be replaced. Officials know this because this is the last variety of kokanee remaining in the Lake Sammamish ecosystem. Two others had runs between August and November. They have been extinct since around 2000. The current, at-risk salmon generally run between November and December.
The work group developed tactics to protect the fish, such as removing fish-blocking culverts, planting trees and shrubs along streams, and increasing public awareness.