Oregon Project: Chinook salmon passage and recovery on the Willamette River

Oregon Project

Chinook salmon passage and recovery on the Willamette River

January 2009 - September 2024

Personnel

Participating Agencies

Portland District
USACE- 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

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
Carey, K.C., M. Kent, C. B. Schreck, C. E. Couch, L. Whitman, and J. T. Peterson. Modeling the effects of stream temperature and human disturbance on prespawn mortality of spring Chinook salmon in an adaptive management framework. North American Journal of Fisheries Management \| Abstract	November 2024	Premature mortality of adult Chinook salmon (<i>Oncorhynchus tshawytscha</i>) is a major barrier to population recovery. Previous studies have attributed population declines to loss of habitat caused by water impoundments and other forms of development. The Willamette River Basin, OR typifies the problems faced by fishery managers in the Pacific Northwest. Although adult salmon are trapped and transported upstream of dams so they can access historic spawning grounds, annual rates of prespawn mortality (PSM) are high (often >40%) and may limit recovery of natural populations if not reduced. The purpose of this study was to identify and develop potential factors related to PSM into a conceptual model with the aim of incorporating future monitoring data to facilitate adaptive management of outplanting operations. We evaluated PSM in Fall Creek of the Willamette River Basin prior to transport facility improvements in summer and fall of 2010-2017 and post-improvement in 2020-2021. We estimated PSM and conducted exploratory analyses to identify possible non-transport sources of stress that may contribute to the observed high PSM rates. Candidate factors included long-term elevated temperature exposure, elevated temperature exposure below the trap, total number outplanted fish, and monthly human disturbance of outplanted fish. We then developed and fit three models each representing a hypothesis of the factor influencing PSM, incorporated them into a single decision model, and conducted sensitivity analyses. PSM averaged 66% over the study period and was greater for females. The top two management actions based on simulation results were to exclude human activity from Fall Creek in August and July, which reduced expected PSM rates to 37% and 38%. Sensitivity analyses indicated that the most influential decision model component was the choice of alternative model. We illustrate how annual monitoring data can be used to update the decision model and improve management, which can ultimately support recovery efforts.

Presentations

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

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

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

Personnel

Participating Agencies

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