Salmon Research

Salmon Research

Summer Chum Supplementation Project

Summer chum salmon in Hood Canal and the Strait of Juan de Fuca were listed as threatened under the US Endangered Species Act in 1999.  Our organization began working with the Washington Department of Fish and Wildlife (WDFW) to supplement the Union River summer chum run in 2000 as part of the Summer Chum Salmon Conservation Initiative, prepared by the WDFW and the Point No Point Treaty Tribes.

From mid-August to mid-October every year since 2000, an adult fish trap at the mouth of the Union River has been operated 24 hours per day by research interns and volunteers to collect data on adult summer chum abundance and to obtain adult chum for artificial spawning and stock supplementation.  In 2003, supplementation ended as the Union River summer chum run was healthy enough that it became a donor stock to reintroduce summer chum to the nearby Tahuya River, where summer chum had been classified as “recently extinct.”  Our organization began releasing summer chum fry into the Tahuya River from the Union River stock in 2004.  750 summer chum returned to the Tahuya River in the first year the project, and since 2006, the Tahuya River summer chum return has been between 200 and 1,000 fish annually. Supplementation efforts concluded with the final fry release in the Tahuya River in early 2015. Monitoring continues on both rivers, with the volunteer-run weir still in place on the Union River.


Union River Summer Chum Trap

2023 Season Final Fish Count









This project, based on a strong partnership between WDFW and the local community, has restored summer-run chum salmon to the Tahuya River and has enriched the community's appreciation of Chum salmon and their ecological importance.

Summer Chum are a key species that returns to Hood Canal rivers at the end of August. They are the first run of “fertilizer” for the Hood Canal during this time of year, keeping the biodiversity of this watershed high. Many species of fish depend on nutrients brought in by Chum during summer, including Chinook, sea-run cutthroat, steelhead, and young coho. Summer Chum bring marine derived nutrients back to the trees, shrubs, insects, birds, and other creatures as well.

August is truly a remarkable time to return to their native rivers; the water levels are low, warm, and nutrient deprived, but chum continue to press on and deliver.

By saving Summer Chum, you are really working to protect so much more. You are helping all other species of salmon, trout, and native plants. They are a keystone species just as much as Chinook – and in fact, chum support the culturally and economically revered Chinook. Summer Chum are important, providing vital fertilizer, nutrients, and supporting our unique ecosystem when no other fish can.

Research Findings

HCSEG is excited to report that we have made positive observations about the future of this threatened salmon population. Due to the rising Summer Chum returns and the Union River estuary restoration project taking place simultaneously, we can confidently attribute the rising return to this habitat restoration effort. It has shown us nature’s powerful ability to rebound, if only given the opportunity and stewardship. 

This chart shows the growth of the Union River Summer Chum population, with an indication for when salmon supplementation ended on the river. It is encouraging to see that the returns continue to grow, even many years after supplementation has ended.