Out-migrant Monitoring of Juvenile Salmonids - FY2025 Hoopa Reservation

Project Objective: Estimate outmigrant abundance across the Hoopa Valley Reservation and to assess restoration success in the Mill and Supply Creek watersheds and to prioritize future restoration actions.

Project Description: The purpose of this project is to estimate the abundance of juvenile anadromous salmonids on reservation tributary streams (Tish Tang, Campbell, Supply, Mill, Pine, Soctish, and Hostler creeks). These streams provide thermal refugia and spawning habitat for anadromous salmonids and are a focus for salmonid habitat restoration. Since 1982, this project has provided juvenile production trend data. This dataset describes annual variation in migration timing and allows for evaluation of outmigrant success in the Mill and Supply Creek watersheds, which were both recently restored. To monitor outmigrants, fyke traps are installed in Reservation streams. Trapped fish are identified, measured (fork length) and released. Depending on the number of fish being caught, a mark-recapture component of the project will be conducted. Numbers of marked and unmarked fish caught are recorded. Resulting data are used to construct abundance estimates for juvenile salmonids. These data are referenced extensively during analysis of timber sales, water withdrawals, and other projects (including drafting of ESA documentation).

SONCC in the lower Trinity River are identified in the Recovery Plan as being at high risk of extinction. Restoration of tributary habitat for both natal and non-natal SONCC is therefore of great importance. This project facilitates the evaluation of spawning and rearing success of anadromous salmonids within Reservation streams, providing managers with necessary data to prioritize potential restoration sites and evaluate restoration success.