Stillaguamish Tribe raising captive broodstock to save South Fork chinook

The Stillaguamish Tribe’s captive juvenile fall chinook soon will have a new home. The tribe has converted an old trout farm into a hatchery facility at Brenner Creek on the South Fork Stillaguamish River.

The tribe expects the Brenner fish hatchery to be completed by the end of the year. The tribe has been rearing the fall juvenile chinook from brood years 2008, 2009 and 2010 at its Harvey Creek Hatchery.

Fall chinook, which mostly rear and spawn in the South Fork Stillaguamish, are genetically distinct from summer chinook, which primarily use the North Fork. A hatchery program has been in place in the North Fork for more than 20 years, with about 1,500 summer chinook returning each year.

Stillaguamish fall chinook by comparison have declined to fewer than 100 fish — so few that there aren’t enough adult chinook in the South Fork to capture and use for broodstock.

For three years, tribal natural resources staff have been seining for juvenile fall chinook, which they raise in small compartments, called “fish condos,” until they are large enough to move to a larger space.

In August, fisheries biologist Carlin McAuley from the federal Manchester Research Station visited the Harvey Creek hatchery to ultrasound the 2008 fish to see if any of them had matured enough to spawn. Three fish, likely males, had matured. “We will learn about how long it takes them to fully ripen up and how long they will last before dying,” Killebrew said.

“With these first captive brood fish, we are learning how to raise, monitor and hold wild chinook salmon from infancy to old age and death,” he added. “We have never tried this before with the Stillaguamish Tribe’s hatchery program and it will help us ramp up a full-scale captive brood program to try and keep South Fork fall-timed chinook from going extinct.”

Watch a video about the program below:

For more information, contact: Kip Killebrew, Stillaguamish Tribe, [email protected], or 360-435-8770; Kari Neumeyer, NWIFC, [email protected] or 360-424-8226.