This project monitors and evaluates Snake River fall Chinook salmon supplementation in the Clearwater River Subbasin and in the mainstem Snake River. Beginning in 2013, two Bonneville Power Administration (BPA) funded fall Chinook monitoring and evaluation (M&E) projects were combined into one for efficiency and to reduce costs. The M&E of Fall Chinook Released Upstream of Lower Granite Dam (project 199801004) was combined with the Nez Perce Tribal Hatchery (NPTH) M&E fall Chinook (project 198335003). Both projects are research and observation projects to determine whether or not artificial propagation can be used to reintroduce, maintain or increase fall Chinook natural production while maintaining the long term fitness of the target population and keeping ecological and genetic impacts on other populations at a minimum. These studies will help determine if supplementation can be used as a tool to help recover the ESA listed Snake River fall Chinook.
Supplementation of the Snake River fall Chinook from Lyons Ferry Hatchery (LFH) began in 1996 with three acclimation facilities constructed upstream of Lower Granite Dam. Acclimation facilities are located on the Snake River at Pittsburg Landing and Captain John Rapids and on the Clearwater River at Big Canyon Creek. Initially, yearling fall Chinook from Lyons Ferry Hatchery were transported, acclimated six weeks, and then released into the Snake and Clearwater rivers. The top priority of the program was to release 450,000 yearling Fall Chinook salmon (150,000 from each facility). Given subsequent increases in fall Chinook returns and production levels, the program has also been acclimating and releasing 1.4 million subyearling fall Chinook salmon annually after yearlings are released.
The NPTH was constructed and began releasing Snake River fall Chinook salmon subyearlings into the Clearwater River subbasin in 2003. Release goals are 500,000 fish directly to the Clearwater River from NPTH near Cherrylane and another 500,000 fish acclimated and released at North Lapwai Valley into Lapwai Creek on the lower Clearwater approximately 12 miles further downstream. Upriver acclimation sites at Lukes Gulch on the S.F. Clearwater River and Cedar Flats on the Selway River each receive 200,000 subyearlings from NPTH for acclimation and release each year.
The M&E program examines the performance and status of hatchery and natural fish in the Clearwater River. We coded wire tag and adipose fin clip a representative sample of all fall Chinook hatchery release groups for harvest evaluations and to monitor adult returns. Other biological evaluation points include juvenile survivals to Lower Granite Dam and through the Columbia River hydrosystem using PIT (passive integrated transponder) tags.Another primary function of this project is to conduct aerial fall Chinook salmon spawning surveys on the Clearwater, Grande Ronde, Imnaha and Salmon rivers to measure spawning escapement and distribution.