Physical Sciences and Mathematics Commons^™

Factors Influencing The Survival Of Outmigrating Juvenile Salmonids Through Multiple Dam Passages: An Individual-Based Approach, Timothy Elder, Christa M. Woodley, Mark A. Weiland, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

Substantial declines of Pacific salmon populations have occurred over the past several decades related to large-scale anthropogenic and climatic changes in freshwater and marine environments. In the Columbia River Basin, migrating juvenile salmonids may pass as many as eight large-scale hydropower projects before reaching the ocean; however, the cumulative effects of multiple dam passages are largely unknown. Using acoustic transmitters and an extensive system of hydrophone arrays in the Lower Columbia River, we calculated the survival of yearling Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) passing one, two, or three dams. We applied a unique index of biological characteristics …