Quantifying Mortal Injury of Juvenile Chinook Salmon Exposed to Simulated Hydro-Turbine Passage

Abstract

A proportion of juvenile Chinook salmon Oncorhynchus tshawytscha and other salmonids travel through one or more turbines during their seaward migration in the Columbia and Snake rivers. There is limited information on how these fish respond to the hydraulic pressures found during turbine passage events. We exposed juvenile Chinook salmon to varied acclimation pressures and subsequent exposure pressures to mimic the hydraulic pressures of large Kaplan turbines. Additionally, we varied abiotic (total dissolved gas and rate of pressure change) and biotic factors (condition factor, fish length, and fish weight) that may contribute to the incidence of mortal injury associated with fish passage through hydropower turbines. We determined that the main factor associated with the mortal injury of juvenile Chinook salmon during simulated turbine passage was the ratio between the acclimation pressure and the lowest exposure pressure. Condition factor, total dissolved gas, and rate of pressure change were found to only slightly increase the predictive power of the equations relating the probability of mortal injury to the conditions of exposure or the characteristics of the test fish during simulated turbine passage. This research should assist engineers and fisheries managers in operating and improving hydroelectric facilities while minimizing mortality and injury to turbine-passed juvenile Chinook salmon. Using these data, models can be built that might determine how much mortal injury is present at different turbine operations as pressures change. Further, pressure data coupled with the mortal injury data should be useful to engineers and turbine manufacturers when designing new turbines, which could not only increase power generation and efficiency but also minimize barotrauma to the fish that pass through them.

Received December 28, 2010; accepted May 25, 2011

ACKNOWLEDGMENTS

Funding for the research described in this report was provided by the U.S. Army Corps of Engineers (USACE), Portland District. The authors thank USACE staff including Blaine Ebberts, Dan Feil, Brad Eppard, and the USACE Turbine Survival Technical Team for their commitment, assistance, and oversight. This research required the assistance of many people. Ralph Elston and the histology staff are thanked for their laboratory support. Ben Tice of Tice Engineering and staff of Reimers Systems, especially Clayton Grable, are thanked for their contributions to the design and troubleshooting of the Mobile Aquatic Barotrauma Laboratory. The authors thank Scott Abernethy, Craig Allwardt, Chris Anderson, Carmina Arimescu, Evan Arntzen, Jim Boyd, Scott Carpenter, Jessica Carter, Kathleen Carter, Kate Deters, Gayle Dirkes, Joanne Duncan, Chris Eilers, Marybeth Gay, Greg Gaulke, David Geist, Allison Hedges, Jill Janak, Kasey Knox, Andy LeBarge, Meng Markillie, Garrett McKinny, Craig McKinstry, Julie Miller, Jennifer Monroe, Tirell Monter, Bob Mueller, Katie Murray, Katie Ovink, Jennifer Panther, Mary Ann Simmons, Marie-Helene Theriault, Jake Tucker, Cherilynn Tunnicliff, Ricardo Walker, Ian Welch, and Christa Woodley of the PNNL. We appreciate the editing assistance of Andrea Currie, PNNL. The PNNL animal facilities used in this research are certified by the Association for the Assessment and Accreditation of Laboratory Animal Care International; fish were handled in accordance with federal guidelines for the care and use of laboratory animals, and protocols for our study were approved by the Institutional Animal Care and Use Committee at Battelle,Pacific Northwest Division. The PNNL is operated by Battelle for the U.S. Department of Energy under Contract DE-AC05–76RL01830.