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.
Gallery: Spawning Chinook, 2020
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!
Spawning Update – Oct. 9, 2020
Oct. 9, 2020: Hatchery staff and volunteers have been spawning our chinook salmon since Sept. 22. After the third spawn, the hatchery has collected just 1.7 million eggs. This year’s goal is 3.3 million eggs, so this may be difficult to achieve.
While the chinook run is bigger than average this year, the vast majority of fish returning to the hatchery are males. The reason for the lopsided return is unknown, but we do know that predators generally prefer to feed on females with their tasty and nutritious eggs. WDFE staff will be picking up chinook eggs Tuesday, October 13 from the Soos Creek Hatchery to supplement our harvest and reach our goal for egg production — as they did last year as well.
Meanwhile, Issaquah Creek is full of spawning chinook below the hatchery, and coho are starting to return as well — although they won’t start spawning until later in October. We have also seen four sockeye in the creek so far.
The unseasonably warm and dry weather this fall has kept fish in Lake Sammamish for the last couple of weeks as they wait for rain to migrate upstream. The next storm should bring an influx of new fish to the hatchery.
Chinook Gives Its All (Including its Tail?)
One of the miraculous facets of a Pacific salmon’s life is its death. All Pacific salmon die after they spawn. In doing so, they enrich their home stream with their harvest of years of nutrition on the high seas. This chinook will feed the local ecosystem, and perhaps even its progeny when they emerge from the gravel in 4 months time.
Betcha Didn’t Know This:
The sharp-eyed among you may note that this chinook’s tail has been cut off. This indicates that a Fisheries Biologist has sampled, measured and counted this fish. Severing the tail ensures that this fish is not counted more than once.
Did you know that ducks are not vegetarians? This photo of mallards feasting on a dead salmon was also taken today on Issaquah Creek.
Updated: Mystery Tags on this Year’s Return
Updated from the original post on Friday, September 25, 2020: Some of the salmon in this year’s return are sporting a highly visible plastic string, telling any observer there is something important about this fish. In particular, this Chinook was captured at the Chittenden Locks by the Muckleshoot Indian Tribe, equipped with an internal tag (acoustic transmitter) that will ping multiple receivers in fixed positions as the fish makes it way from the Locks, through the Lake Washington Ship Canal, Lake Washington, the Sammamish River, Lake Sammamish, and finally, Issaquah Creek. The main purpose of tagging the hatchery fish is to document survival during their migration from the Locks to the hatchery. The last couple of years we have noticed a difference in numbers between the Lock counts and what shows up at the hatchery so we are trying to find out if and where we are losing fish.
Small Group Tours are Going Swimmingly!
If you haven’t signed up to take our small group tours at the hatchery, what are you waiting for?!
Tours are limited to 5 people per tour group. Get your free tickets online at eventbrite HERE.
- Tickets are free, with donations encouraged.
- Tours times will be listed on eventbrite (according to docents’ availability).
Please note that entry to the hatchery grounds is restricted exclusively to ticket holders during their allotted tour time. The hatchery is currently closed to walk-up visitors.
Share the wonders of salmon this season with us in a small group tour!
Gallery: Photos of our Small Group Tours
- Chinook Spawning Season Final Report 2020
- Spawning Update – Oct. 9, 2020
- Chinook Gives Its All (Including its Tail?)
- Updated: Mystery Tags on this Year’s Return
- Small Group Tours are Going Swimmingly!
- Deterring Seal Predation at the Locks
- UPDATE: Get your Hatchery Tour Tickets!
- Big Chinook Return! Small Spawning Results. Why is That?
- A Second Transfer of Kokanee to Orcas Island!
- Hatchery Spring Release Report