Anadromous adult Pacific salmon (Oncorhynchus spp.) encounter hydraulically
challenging areas of difficult passage (high-gradient reaches, dams) during their
reproductive migration. While the direct effects of dam operations on wild fishes are well
documented (e.g., delayed movements, excessive energy-use), comparatively little is
known as to the delayed, post dam passage effects of these barriers. Using acoustic
accelerometer transmitters and model selection analyses, Chapter 2 assessed how
managed flow releases from a dam influenced the swimming activity, behaviour and
passage
success of sockeye salmon (O. nerka). Building on this framework, Chapter 3
explored the potential for high-flow-induced burst swimming below the dam to predict
the mortality of sockeye salmon. Findings from this research provide novel insight into
the mechanisms that contribute to the delayed mortality of migratory fishes. Future
studies investigating the indirect effects of dams will improve our ability to provide
effective passage solutions to watersheds that are impacted by hydropower development.