This project expands RM & E activities conducted by the co-managers in the Yakima Basin (Yakama Nation and Washington Department of Fish and Wildlife) to better evaluate VSP parameters (abundance, productivity, spatial structure, and diversity) for Yakima steelhead populations.  This proposal builds upon the infrastructure and monitoring capacities of the YKFP umbrella M&E project (199506325). Data from this project will be used to evaluate population status and trends, inform NOAA status reviews and implementation of the CRSO Biological Opinion, and address status an trends of Steelhead consistent with the NPCC Fish and Wildlife program, Columbia Basin research plan (uncertainties 3.1, 7.1 & 7.3), NOAA mid-Columbia steelhead recovery plan, and Fish Accords. The improved understanding of steelhead population performance produced by this project will provide long term Status and trends monitoring data for the Yakima River Steelhead MPG populations, and directly inform efforts to recover steelhead populations in the Yakima Basin.

Specific activities include:

1. Maintaining biological and DNA sampling at Prosser adult monitoring facility (Abundance, Productivity),

2. PIT tagging of Juvenile O.mykiss in Naches River, and adults at Prosser Dam (Abundance, Productivity, Spatial Structure),

3. Data analyses will include generating independent adult spawner escapement estimates for individual populations using PIT-tag detection data from instream arrays. Other biological data to be analyzed includes the life history characteristics of individual populations (run timing, adult holding, prespawn survival, spawn timing, kelt rates and respective outmigrant survival) and analysis of age data for Cohort analysis (adult productiivity). Age data will be evaluated for the Yakima MPG as a whole and for individual populations

4. Installation and maintenance of PIT-tag detection antennas. Using the telemetry data, the project has identified the last of key locations needed for long term status and trends monitoring (spawning escapement for individual populations). These include Sunnyside Dam, and Marion Drain (both will use cost effective allflex antennas and reader boards). The project will also conduct routine maintenance on all Yakima River Instream PIT-tag detection arrays funded by this project.

5. Naches River- Compilation of PIT- tagging effort, detection history, rearing patterns, and life stage specific survival estimates (outmigrant survival, Smolt-to-adult return rates).

6. Evaluate interactions in the upper Yakima and Naches between resident rainbow and steelhead trout (Diversity, Productivity).
This project addresses CRSO Terms and Conditions for continued fish monitoring to support NOAA species status assessments.