Project: COLLECTION EFFICIENCIES, TRAVEL TIMES, INJURY AND SURVIVAL OF SALMONIDS AND LAMPREY FOLLOWING RELEASE INTO A MODIFIED BYPASS FACILITY AT LOWER GRANITE DAM, WA
Client: USACE - Walla Walla District
Location: Lower Columbia and Snake RiversGoals of this study were to (1) evaluate travel times and fish injury associated with passage through prototype structures (a weir and enlarged orifice) at a bypass facility, (2) characterize reservoir-specific downstream travel times, (3) estimate downstream collection and survival probabilities, and (4) evaluate if collection and survival probabilities were related to individual fish characteristics measured across multiple species at Lower Granite Dam.
Reducing travel times and fish injury rates associated with dam passage is a priority in efforts to protect fish populations in the Columbia River Basin. In 2014, research was conducted to evaluate travel times and fish injury rates associated with passage through prototype passage structures (sharp-crested overflow weir, enlarged orifice) at the Lower Granite Dam bypass facility. Research was conducted with five different species and age-classes of fish. Preliminary results indicated that only minor damage occurred in most fish species during passage through prototype structures; indicating efforts to modify dam passage routes to be more fish friendly are working. Preliminary study results also indicated that following passage through Lower Granite Dam, individual fish characteristics, including length and external condition, affected downstream survival and collection probabilities. Finally, preliminary results indicating that although damage rates at Lower Granite Dam were low, fish in degraded condition were less likely to survive outmigration. The ability to non-destructively assess fish condition and subsequently track fish behavior and survival is becoming vital to our understanding of natural and anthropogenic stressors and sources of fish mortality.
Project involved multiple partners including, University of California - Davis, Blue Leaf Environmental, and Biomark.