Cooperative Fish and Wildlife Research Units Program: Oregon
Education, Research and Technical Assistance for Managing Our Natural Resources

Oregon Project

Chinook salmon passage and recovery on the Willamette River

January 2009 - September 2024


Participating Agencies

  • USACE- Portland District
  • Portland District
  • USACE Portland District

Willamette River basin adult spring-run Chinook salmon (Oncorhynchus tshawytscha) are prevented from returning to their historic spawning grounds by large dams managed jointly by the U.S. Army Corps of Engineers (USACE), Bonneville Power Administration, and Bureau of Reclamation. In response, USACE and Oregon Department of Fish and Wildlife biologists initiated an adult transportation program in the 1990’s with an objective of facilitating natural spawning of these populations above the dams. Unfortunately, annual rates of pre-spawn mortality (PSM) in adult Chinook salmon transported upstream of dams are high (often >40%), and could limit the ability to establish a natural population of spring Chinook if not reduced. The progeny of these outplanted adults face similar downstream passage difficulties that is further complicated by very high parasitic infection rates (>90%) of a native copepod (Salmincola californiensis). The infections affect the ability of outmigrating juvenile to swim, withstand stressors, and survive in saltwater during their ocean transition. This is an integrated project whose ultimate goal is the safe passage of juvenile and adult spring-run Chinook salmon to assist in the recovery of this listed stock.

Research Publications Publication Date
Dolan, B.P., K. M. Fisher, M. E. Colvin, S. E. Benda, J. T. Peterson, M. L. Kent, and C. B. Schreck. 2016. Innate and adaptive immune responses in migrating spring-run adult Chinook Salmon, Oncorhynchus tshawytscha. Fish and Shellfish Immunology 48:136-44 February 2016
DeWeber, J.T., J.T.Peterson, C. Sharpe, M.L. Kent, M.E. Colvin, C.B. Schreck. A hidden-process model for estimating prespawn mortality using carcass survey data. North American Journal of Fisheries Management January 2017
Colvin, M.E., J.T. Peterson, M. L. Kent, and C. B. Schreck. 2015. Occupancy modeling for improved accuracy and understanding of pathogen prevalence and dynamics. Plos ONE. 10(3): e0116605. doi:10.1371/journal.pone.0116605 March 2015
Colvin, M.E., J.T. Peterson, C. Sharpe, M.L.Kent, C.B. Schreck. 2018. Identifying optimal translocation policies given factors associated with adult spring-run Chinook Salmon translocation mortality. River Research and Applications 34:1158–1167 December 2018
Presentations Presentation Date
Peterson, J.T., J. Sanders, T. Neal, M. Kent and C. Schreck. 2020. The Willamette Copepod Research Program: Infection experiments and impacts on juvenile Chinook salmon. Willamette Fisheries Science Review, Corvallis OR, February 11-12 February 2020
Neal, T., M.L. Kent, J. Sanders, C.B. Schreck, and J. Peterson. 2020. Experimental infection of the parasitic copepod on juvenile Chinook salmon. Annual Meeting of the Oregon Chapter of the American Fisheries Society, March 4-6, Bend, OR. March 2020
Herron, C.L, O. M. Hakanson, M. M. Scanlan, C.E. Couch, C. B. Schreck, and J. T. Peterson. 2023 The Wild Fishes Surrogate Project: Where We Have Been, Are, And Will Be. Willamette Fisheries Science Review Corvallis OR April 5-6. April 2023
Carey, K., L. Whitman, C. Sharpe, C. Couch, M.L. Kent, J. Sanders, C.B. Schreck, and J.T. Peterson. 2023. Prespawning Mortality of Fall Creek Willamette Chinook Salmon: Evaluation Of The Effects Of A New Trap At The Adult Fish Collection Facility. Willamette Fisheries Science Review Corvallis OR April 5-6. April 2023
Theses and Dissertations Publication Date
Benda, S.E. 2014. Cool, pathogen free refuge lowers pathogen associated prespawn mortality of Willamette River Chinook salmon (Oncorhynchus tshawytscha) . Masters Thesis, Oregon State University, Corvallis. July 2014