The steelhead population in the Skokomish River has doubled since the Skokomish Tribe started a supplementation project in 2006, part of a 16 year-long project to boost the steelhead population in Hood Canal.

“The increase in the number of egg nests has given us an early indication that the project is working, but the long-term monitoring will be the true test of its success,” said Matt Kowlaski, the tribe’s steelhead biologist. “We expect numbers to continue to increase over the next four years because there will be active supplementation of steelhead into the river. After the project is over, we expect the egg nest numbers to likely flatten out or decrease, but hopefully remain at elevated levels.” 

Staff and volunteers from the Skokomish Tribe and NOAA collect steelhead eggs for a long-term steelhead study.

Staff and volunteers from the Skokomish Tribe and NOAA collect steelhead eggs for a long-term steelhead study. Click on the photo for more pictures at NWIFC’s Flickr page.

The tribe has spent the past eight years collecting 30,000 eggs a year from the Skokomish River. The eggs, collected between May and June, have been raised to smolts in a state hatchery, then released into the river, except for 400 of them. Those 400 have been raised to four-year-old adults in a federal hatchery and then released to increase chances of spawning in the river.

The eggs collected are considered naturally spawned steelhead, Kowlaski said, but their adipose fin is clipped so they can be differentiated in the field.

Now that egg collection is over, the next eight years will be focused on monitoring and counting salmon egg nests and observing changes in spawning areas, life history and genetic diversity, Kowalski said.

The National Oceanic and Atmospheric Administration is conducting genetic testing to determine changes in diversity and parental lineage throughout the population.

“One of the main goals of the project is to increase the number of steelhead without decreasing genetic and life history diversity,” he said.

The tribe has focused on the south fork of the Skokomish River, but it is just one of several of the major Hood Canal rivers that are part of the project. The Duckabush and Dewatto rivers are also supplemented with steelhead; Tahuya, Big Beef, Hamma Hamma, Dosewallips and Little Quilcene rivers are not supplemented to provide a comparison.

Puget Sound steelhead are listed as “threatened” under the federal Endangered Species Act.

Other partners in the study are Jamestown S’Klallam Tribe, Port Gamble S’Klallam Tribe, Puget Sound Partnership, Washington Department of Fish and Wildlife, U.S. Fish and Wildlife Service, U.S. Forest Service, Point No Point Treaty Council, Long Live The Kings, Hood Canal Salmon Enhancement Group, Hood Canal Coordinating Council and Tacoma Power.

See a video of the egg sampling here.