Background: In 2010, after a ten-year evaluation by WDFW of an endemic stock test-program in the Tucannon River, state and tribal co-managers (Nez Perce and Umatilla), supported by the Lower Snake River Compensation Program (LSRCP), agreed to implement an endemic steelhead supplementation program. Concurrent with that decision, releases of Lyons Ferry stock steelhead into the Tucannon River were stopped as a harvest mitigation program (under the LSRCP). These actions are consistent with the recommendations of the recently completed HSRG (2009) and HRT (2009) hatchery reviews; and supported by the direction of NOAA Fisheries in the 2008 Biological Opinion (BiOp), the 2017 Biological Opinion (BiOp) to implement the Tucannon River endemic steelhead hatchery supplementation program (RPA 40.2). NOAA Fisheries recently consultation on this program and approved Section 10 Permit #18025 for this program.

The primary goal of this hatchery supplementation program will be to increase total abundance of spawning steelhead and for the long-term conservation of natural origin summer steelhead in the Tucannon River. A second goal is to provide harvest as part of the LSRCP mitigation program in the Tucannon River, once the endemic hatchery program is expanded to full production (150,000 smolts annually).

Purpose: This project was initiated to provide support for the level of monitoring and evaluation sufficient to determine if the supplementation program goals are being met.

Note: Changes in the hatchery program will require facility modifications to provide additional rearing space at Lyons Ferry Hatchery to accommodate the planned expansion in production; actions to modify the hatchery are expected to occur through agreements with LSRCP and BPA, but are still pending [March 2018].