So far, it appears to be a solid return year for the rare, fresh-water salmon swimming back to their spawning grounds in Sammamish and Bellevue. Likely 4,000 kokanee, a species closely related to the sockeye salmon but which only live in Lake Sammamish, will have returned to familiar breeding streams by spring, estimated David St. John, coordinator and chair of the Lake Sammamish Kokanee Work Group.
These numbers would make this year’s return the third highest in the last two decades, he said.
Since 2009, per the Issaquah Salmon Hatchery program, crews have been collecting and raising kokanee offspring before releasing them back into native creeks. This strengthens the species’ numbers and increases their chance of survival. This year, hatchery crews collected about 145,000 eggs, the second most ever gathered, St. John said.
And since 2010, the hatchery program has brought more than 300,000 kokanee fry back to native waters. The 2015 Kokanee Release saw 46,000 baby fish returned to local streams.
This year’s return, the 2015-2016 run, are the offspring of a large spawning group in 2012-2013 when an estimated 15,000 fish swam back to native streams.
“When we talk about having a ‘good year’ it’s relative. Historically speaking, these are all bad years,” St. John said. “We need to do better.”
Once, the kokanee thrived in the tens of thousands, St. John said. In recent decades the species saw a dramatic decline in population, on the “brink of extinction” King County Executive Dow Constantine said in 2011.
Even with the relatively strong return in 2012-2013, officials are still not seeing the full production of those fish. That run should have produced more like 20,000 fish, but instead, the county is seeing ⅓ of that, St. John said.
There are two possible theories to explain this: either there’s not enough food in the lake to support the offspring, or there’s not enough habitat in the creeks for them to spawn in. The latter would result in kokanee returning later in the year potentially clearing away laid eggs to make room for their own.
“That would mean we would need to restore access to Zaccuse Creek, restore access to George Davis Creek,” St. John said.
Though kokanee once inhabited many streams feeding into the lake, they know only return to three: Ebright Creek and Laughing Jacobs Creek on the Plateau, as well as Lewis Creek in Bellevue.
The 2015-2016 return numbers won't be official until the spring, St. John said.