Native kokanee salmon show promising signs of health after enacting recommendations from the Lake Sammamish Kokanee Work Group

Last fall, biologists observed over 2,000 adult kokanees returning from the lake to spawn.

Four years after Executive Dow Constantine announced that King County would enact recommendations from the Lake Sammamish Kokanee Work Group, biologists are seeing promising signs of health for the native kokanee salmon population found in Lake Sammamish.

During the 2017 return, county, state, and federal biologists counted fewer than 20 kokanees. In 2018, Executive Constantine announced the King County Department of Natural Resources would enact recommendations from the Lake Sammamish Kokanee Work Group to prevent the possible extinction of kokanee salmon following a sudden and alarming decline in spawners returning to streams around Lake Sammamish.

Last fall, biologists observed over 2,000 adult kokanees returning from the lake to spawn in tributary creeks, which is more than the total number of spawners biologists observed over the previous five years.

“Four years ago we committed to taking immediate action to help ensure the survival of these iconic fish by mobilizing our combined resources and applying the latest science and technology—and today we are delivering on that share vision,” said Executive Constantine.

Lake Sammamish Kokanee Work Group is an alliance of tribal and local governments, state and federal agencies, nongovernmental organizations, landowners, and residents of the watershed. Based on the group’s recommendations to protect kokanee salmon, King County and its partners are using specially designed traps to capture a small number of returning spawners for the hatchery program.

Additionally, the recommendations are leading partners to release young salmon into Lake Sammamish during the fall, after the lake’s temperatures cool and when oxygen levels rise. Partners will also be using the latest cryopreservation technology to protect the unique genetic stock of Lake Sammamish kokanee, while also reintroducing kokanee salmon to additional creeks in the watershed using egg boxes, which reduce the risk of floods or droughts in a single creek wiping out the entire run.

“This inspiring work by our staff and partners is producing promising results for a native salmon species that is important to our region’s habitat and history,” said Executive Constantine.

A contributing factor to the recent increase in returning spawners comes from King County, the City of Sammamish, and waterfront residents removing barriers to streams and tributaries, according to the biologists.

Kokanee salmon remain culturally significant while also remaining crucial to biodiversity throughout the region. Kokanees have a unique genetic signature—which has been adopted over centuries in the Lake Sammamish ecosystem—making them impossible to replace, according to King County Department of Natural Resources and Parks. Kokanee salmon are one out of four known genetically distinct salmon populations in Washington.

The focus of current kokanee conservation efforts is on the run that occurs in November and December, which is also known as the ‘late run’. A run that historically occurred in late August and September in Issaquah Creek was driven down to extinction between the 1970s and the early 2000s. Biologists believed that the late run—which historically occurred in October and November in the Sammamish River and Lake Washington—was extinct, however recent investigations may have located a small remainder of that population.