NOAA Technical Memorandum NMFS-NWFSC-118 Scientific Conclusions of the Status Review for Oregon Coast Coho Salmon (Oncorhynchus kisutch) June 2012 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service Northwest Fisheries Science Center NOAA Technical Memorandum NMFS-NWFSC Series The Northwest Fisheries Science Center of the National Marine Fisheries Service, NOAA, uses the NOAA Technical Memorandum NMFS-NWFSC series to issue scientific and technical publications. Manuscripts have been peer reviewed and edited. Documents published in this series may be cited in the scientific and technical literature. The NMFS-NWFSC Technical Memorandum series of the Northwest Fisheries Science Center continues the NMFS- F/NWC series established in 1970 by the Northwest & Alaska Fisheries Science Center, which has since been split into the Northwest Fisheries Science Center and the Alaska Fisheries Science Center. The NMFS-AFSC Technical Memorandum series is now used by the Alaska Fisheries Science Center. Reference throughout this document to trade names does not imply endorsement by the National Marine Fisheries Service, NOAA. This document should be referenced as follows: Stout, H.A., P.W. Lawson, D.L. Bottom, T.D. Cooney, M.J. Ford, C.E. Jordan, R.G. Kope, L.M. Kruzic, G.R. Pess, G.H. Reeves, M.D. Scheuerell, T.C. Wainwright, R.S. Waples, E. Ward, L.A. Weitkamp, J.G. Williams, and T.H. Williams. 2012. Scientific conclusions of the status review for Oregon coast coho salmon (Oncorhynchus kisutch). U.S. Dept. Commer., NOAA Tech. Memo. NMFS-NWFSC-118, 242 p. NOAA Technical Memorandum NMFS-NWFSC-118 Scientific Conclusions of the Status Review for Oregon Coast Coho Salmon (Oncorhynchus kisutch) Heather A. Stout, Peter W. Lawson, Daniel L. Bottom, Thomas D. Cooney, Michael J. Ford, Chris E. Jordan, Robert G. Kope, Lance M. Kruzic,1 George R. Pess, Gordon H. Reeves,2 Mark D. Scheuerell, Thomas C. Wainwright, Robin S. Waples, Eric Ward, Laurie A. Weitkamp, John G. Williams, and Thomas H. Williams3 Northwest Fisheries Science Center 2725 Montlake Boulevard East Seattle, Washington 98112 1NMFS Northwest Regional Office 2900 Northwest Stewart Parkway Roseburg, Oregon 97471 2U.S. Forest Service Pacific Northwest Research Station 333 Southwest First Avenue Portland, Oregon 97204 3Southwest Fisheries Science Center 110 Shaffer Road Santa Cruz, California 95060 June 2012 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service Most NOAA Technical Memorandums NMFS-NWFSC are available at the Northwest Fisheries Science Center Web site, http://www.nwfsc.noaa.gov Copies are also available from the National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Phone orders: 1-800-553-6847 E-mail orders: [email protected] ii Table of Contents List of Figures ............................................................................................................................................... v List of Tables .............................................................................................................................................. vii Executive Summary ..................................................................................................................................... ix Acknowledgments ...................................................................................................................................... xiii Introduction ................................................................................................................................................... 1 Summary of Previous BRT Conclusions ...................................................................................................... 7 ESU Determination................................................................................................................................... 7 Status Evaluation in 1994 ......................................................................................................................... 9 Status Evaluation in 1996 ......................................................................................................................... 9 Status Evaluation in 2003 ....................................................................................................................... 11 New Contributions to Understanding and Assessing Status of Oregon Coast Coho Salmon ..................... 14 ESU Delineation ..................................................................................................................................... 14 Artificial Propagation—Membership in the ESU ................................................................................... 15 Population Delineation ........................................................................................................................... 15 Definition of Biogeographic Strata ......................................................................................................... 18 Biological Recovery Criteria Used to Inform Risk Assessment ............................................................. 18 New Comments ........................................................................................................................................... 20 Oregon Coast Coho Salmon Symposium .................................................................................................... 23 New Data and Updated Analyses................................................................................................................ 26 Current Biological Status ........................................................................................................................ 26 Factors for Decline and Threats .............................................................................................................. 53 Overall Risk Assessments ......................................................................................................................... 114 Risk Matrix Approach .......................................................................................................................... 115 Summary of Risk Conclusions ............................................................................................................. 117 Significant Portion of its Range Question ............................................................................................ 119 Glossary .................................................................................................................................................... 121 References ................................................................................................................................................. 129 Appendix A: Threats Matrix and DSS Criteria ......................................................................................... 153 Appendix B: Disturbance .......................................................................................................................... 157 iii Appendix C: Summary of Findings of the BRT-ODFW Habitat Trends Working Group ....................... 163 Introduction .......................................................................................................................................... 163 Methods ................................................................................................................................................ 165 Results .................................................................................................................................................. 168 Summary ............................................................................................................................................... 172 Appendix D: Peer Reviews and Public Comments with the BRT’s Responses ....................................... 175 Comments of Eight Peer Reviewers ..................................................................................................... 175 Comments of the Oregon Department of Fish and Wildlife ................................................................. 193 Comments of the MidCoast Watersheds Council Coordinator ............................................................ 205 Comments of Douglas County, Oregon................................................................................................ 212 iv List of Figures Figure 1. West Coast coho salmon ESUs .................................................................................................... 3 Figure 2. Critical habitat designation for the OCCS ESU, February 2008 .................................................. 5 Figure 3. Historical populations and biogeographic strata for OCCS ESU ............................................... 17 Figure 4. OCCS naturally produced recruits per spawner, 1972–2009 ..................................................... 28 Figure 5. OCCS naturally produced recruits, 1969–2008 .......................................................................... 28 Figure 6. Comparison of historical and recent estimates of spawner abundance and preharvest recruits ....................................................................................................................................... 29 Figure 7. Trends in natural spawner abundance for the whole ESU and the five biogeographic strata ...................................................................................................................................