Chinook Spawning Season Final Report 2020

The 2020 chinook spawning season is drawing to a close, and we’ve seen a lot of fish spawning in Issaquah Creek! The hatchery concluded the chinook spawning season on Oct. 13 with the fourth weekly egg take of the run. Hatchery staff and volunteers, all wearing masks, socially distanced, spawned a season total of 881 chinook hens and bucks, and collected 1.8 million eggs. Disappointingly, this number fell short of our goal of 3.2 million, so the Soos Creek Hatchery has provided 1.5 million extra chinook eggs to the Issaquah Hatchery for a total of 3.3 million eggs.

For the season, our hatchery saw roughly 2,348 chinook (35 natural origin) jump up the fish ladder and into the holding ponds. For the Greater Lake Washington Watershed, more than 12,000 chinook were counted entering the fresh water at the Ballard Locks. Some of those salmon headed to other streams to spawn, and many spawned downstream of the hatchery in Issaquah Creek.

Due to our warm, dry weather this fall, it was feared that a number of the chinook would not make it back to their spawning grounds. Those that did arrive were overwhelmingly male: about 75 percent, as the females are preferred by predators such as seals, sea lions and orcas. 

Although the number of fish arriving at the hatchery this year was fewer than average, the hatchery released 51 chinook upstream above the weir to spawn in the upper reaches of Issaquah Creek. These were fish that were not ripe by the final spawning day at the hatchery. 

The good news is that the weekend rains brought lots of coho upstream! At least 1,200 are currently trapped in the holding pond as of this writing. Coho spawning is expected to start in late October and continue through mid-November. Let’s route for big numbers this year!