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Relating Juvenile Salmonid Use and Channel Hydraulics to Full-Channel Engineered Log Jam Structures. Jennifer Lee, B.S. Harvey Mudd College Kristen Shearer, Wittenberg University John Vivio , University of California, San Diego Advisors: Matt Cox, M.S. Oregon State University
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Relating Juvenile Salmonid Use and Channel Hydraulics to Full-Channel Engineered Log Jam Structures Jennifer Lee, B.S. Harvey Mudd College Kristen Shearer, Wittenberg University John Vivio, University of California, San Diego Advisors: Matt Cox, M.S. Oregon State University Desiree Tullos, Ph.D. Oregon State University Ecology Informatics Summer Institute2011
Background • Spawning salmonid species in the Northwest use wood in streams for: • Obtaining food • Cover from predators • Favorable hydraulic features • Engineered Log Jams (ELJs) used to supplement natural fish habitat and livelihood in streams, and increase habitat complexity
Overview • History • Purpose & Objectives • Questions • Hypotheses • Site Description • Materials & Methods • Results & Discussion • Conclusion
History • Logging • Since 1800s • Decreased quantity of natural wood falling into streams • Splash dams created to transport logged wood to sawmills by raising water levels in streams • Widened channels • Scoured away accumulated sediment to expose bedrock • Eliminated natural log jams to create clear path for logs • Reduced natural habitat
History • Removal of woody debris for habitat • 1950s to 60s • Large wood thought to impede fish migration in streams • Later realized to play an important role in fish habitat and livelihood • Development of Engineered Log Jams • Endangered Species Act (1973) • Replenish lost wood back into streams
Purpose • Study the effect of ELJs on • Fish behavior • Stream hydraulics • Pools and eddies • Bathymetry and channel width • Provide information for future plans to install ELJs in streams
Objectives • Take velocity measurements of the stream along transects • Take bathymetry data of stream beds • Survey sites using coordinate measurements • Observe fish placement and behavior during 24-hour snorkel surveys • Combine and correlate velocity, bathymetry, and fish placement data
Questions • How do streams flow near ELJs? • What kind of flow do fish prefer? • How do fish use ELJs to their advantage? • How do ELJs affect channel morphology in different systems?
Hypotheses • Fish • Prefer lower flow to expend less energy • Prefer covered, deeper channels • Use log jams for shelter • Stream hydraulics • Add complexities to flow • Increase mixing of water column • Increase amount of organic material in the stream • Channel Morphology • Increased bathymetric complexity • Smaller particles accumulate near the jams
Site Description:Quartz Creek Downstream Upstream
Site Description:Fall Creek River Right River Left View from upstream of the log jam
Site Description:Fall Creek River Left from downstream of the log jam on the gravel bar River Left from downstream of the log jam
Materials & Methods:Total Station and ADCP Acoustic Doppler Current Profiler (ADCP) Total Station and prism reflector
Results:Bathymetry of Quartz Creek Root Wad Logs
Results:Bathymetry of Fall Creek River Left Log Jam Gravel Bar River Right Quartz Creek
Results:Velocity Magnitudes of Quartz Creek Averaged Bottom
Results:Bathymetry and Fish of Quartz Creek Root Wad Logs
Results: Bathymetry and Fish of Fall Creek River Left Log Jam Gravel Bar River Right
Results: Bottom Velocity Magnitudes and Fish of Fall Creek River Left Log Jam Gravel Bar River Right
Results: Velocity Magnitudes and Fish of Fall Creek River Left Log Jam Gravel Bar River Right Quartz Creek
Conclusions • How do streams flow near ELJs? • Turbidity of water • What kind of flow do fish prefer? • Slower flow adjacent to fast flow • How do fish use ELJs to their advantage? • Increased flow complexity • Channel complexity • Cover • Spawning
Conclusion • How do ELJs compare and contrast in different systems? Fall • Smaller pieces of wood • Flow splits to go either through and under or around jam • Coho was dominant Quartz • Key piece log • Flow goes through or under jam • Cutthroat was dominant
Thank you to… Desiree Tullos Matt Cox Chris Gabrielli Cara Walter David Hill Roy Rivera Kate Meyer Jorge Ramirez David Noakes Ryan Couture Joseph O’Neil National Science Foundation Oregon State University US Department of Agriculture and Forestry