At the Northwest Power and Conservation Council’s June 13, 2013 request, the ISRP reviewed the Washington Department of Fish and Wildlife and Nez Perce Tribes’ proposal Snake River Fall Chinook Monitoring and Evaluation (#2012-013-00). This study proposes to 1) determine fidelity to release location of returning adult fall Chinook released as subyearling smolts from acclimation ponds or directly released without an acclimation period; and to 2) quantify fallback behavior of adult fall Chinook at Lower Granite Dam. The proposal states that distribution of hatchery-origin spawners is important for understanding the potential effects of the supplementation program on natural Chinook salmon. The proposal also notes that determining Chinook fallback at Lower Granite Dam is important when constructing escapement and productivity estimates.
The ISRP finds that the proponents developed a good proposal that addresses an important issue while cost-effectively building upon previous and ongoing efforts. Specifically, the investigation has significant management implications for fall Chinook hatcheries in the Snake River basin. The ISRP recommends that the proposal Meets Scientific Criteria (Qualified). The qualification is that the proponents should consider the ISRP’s comments while planning, implementing, and reporting the findings of this investigation. The ISRP’s comments stem from unclear explanation of complex issues rather than a flaw in the study design.
The ISRP recommends that to fully benefit from the relatively large number of returning PIT-tagged fall Chinook in 2013, the study should begin as soon as possible, so that additional planning and radio-tagging of the adults may begin without delay.