Status of Cowcod (Sebastes levis) in 2019 Photo: R. Lea E.J. Dick* and Xi He * Corresponding author: [email protected] Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic and Atmospheric Administration 110 McAllister Way, Santa Cruz, CA 95060 October 24, 2019 This report may be cited as: Dick, E.J. and He, X. 2019. Status of Cowcod (Sebastes levis) in 2019. Pacific Fishery Management Council, Portland, OR. Available from http://www.pcouncil.org/groundfish/stock-assessments/ Glossary of Acronyms: ABC: Acceptable Biological Catch ACL: Annual Catch Limit ACT: Annual Catch Target CAAL: Conditional age at length CalCOFI: California Cooperative Oceanic Fisheries Investigations CALCOM: California Cooperative Groundfish Survey CCGS: California Cooperative Groundfish Survey CDFW (CDFG): California Department of Fish and Wildlife (formerly Fish and Game) CPFV: Commercial Passenger Fishing Vessel (aka “party” or “charter” boats) CPUE: Catch-per-unit-effort CRFS: California Recreational Fisheries Survey FED: Fisheries Ecology Division INPFC: International North Pacific Fisheries Commission LACSD: Los Angeles County Sanitation District MRFSS: Marine Recreational Fisheries Statistics Survey NMFS: National Marine Fisheries Service NOAA: National Oceanic and Atmospheric Administration NWFSC: Northwest Fisheries Science Center OCSD: Orange County Sanitation District ODFW: Oregon Department of Fish and Wildlife OFL: Overfishing Limit PacFIN: Pacific Fisheries Information Network PFMC: Pacific Fishery Management Council PSMFC: Pacific States Marine Fisheries Commission RecFIN: Recreational Fisheries Information Network SPR: Spawning Potential Ratio SS: Stock Synthesis STAR: Stock Assessment Review (Panel) STAT: Stock Assessment Team SWFSC: Southwest Fisheries Science Center WCGBT: NWFSC West Coast Groundfish Bottom Trawl (WCGBT) Survey. WCGOP: West Coast Groundfish Observer Program YOY: Young-of-the-year Table of Contents Executive Summary ............................................................................................ i Stock ............................................................................................................................................ i Catches ........................................................................................................................................ i Data and assessment ............................................................................................................... ii Stock biomass ........................................................................................................................... ii Recruitment .............................................................................................................................. iv Exploitation status .................................................................................................................... v Ecosystem considerations ................................................................................................... viii Reference points .................................................................................................................... viii Management performance ...................................................................................................... ix Unresolved problems and major uncertainties .................................................................... ix Decision table ............................................................................................................................ x Scientific uncertainty .............................................................................................................. xii Research and data needs ....................................................................................................... xii 1 Introduction ................................................................................................. 1 1.1 Basic Information ........................................................................................................... 1 1.2 Map................................................................................................................................... 1 1.3 Life History ...................................................................................................................... 1 1.4 Ecosystem Considerations ........................................................................................... 2 1.5 Fishery Information ........................................................................................................ 2 1.6 Summary of Management History ................................................................................ 3 1.7 Management Performance ............................................................................................ 4 1.8 Fisheries off Mexico ....................................................................................................... 4 2 Assessment ................................................................................................. 4 2.1 Data .................................................................................................................................. 4 2.1.1 Fishery-Dependent Data ........................................................................................... 4 2.1.2 Fishery-Independent Data ...................................................................................... 10 2.1.3 Biological Data ........................................................................................................ 18 2.1.4 Data Sets Considered But Not Used in Assessment ............................................. 22 2.2 Model ............................................................................................................................. 24 2.2.1 History of Modeling Approaches Used for this Stock ............................................. 24 2.2.2 Response to STAR Panel Recommendations from the 2013 assessment ........... 25 2.2.3 New Modeling Approaches ..................................................................................... 26 2.2.4 Transition to the Current Stock Assessment .......................................................... 26 2.2.5 Model Specifications ............................................................................................... 29 2.2.6 Model Parameters ................................................................................................... 30 2.3 Base Model Selection and Evaluation ....................................................................... 30 2.3.1 Key Assumptions and Structural Choices .............................................................. 30 2.3.2 Evaluation of Model Parameters ............................................................................ 31 2.3.3 Residual Analysis .................................................................................................... 31 2.3.4 Convergence ............................................................................................................. 32 2.4 Response to STAR Panel Recommendations .......................................................... 32 2.5 Base-Model(s) Results................................................................................................. 37 2.6 Evaluation of Uncertainty ............................................................................................ 38 2.6.1 Sensitivity to Assumptions, Data, and Weighting ................................................... 38 2.6.2 Parameter Uncertainty ............................................................................................ 41 2.6.3 Retrospective Analysis ........................................................................................... 42 2.6.4 Historical Analysis ................................................................................................... 42 3 Reference Points ....................................................................................... 43 4 Harvest Projections and Decision Tables ................................................ 43 5 Regional Management Considerations .................................................... 43 6 Research Needs ........................................................................................ 44 7 Acknowledgments ..................................................................................... 45 8 Literature Cited .......................................................................................... 45 9 Auxiliary Files ............................................................................................ 50 10 Tables ..................................................................................................... 51 11 Figures .................................................................................................... 90 Appendix A. Federal Commercial Fishery Regulations Related to Cowcod171 Appendix B. Catch-based estimates of sustainable yield for cowcod (Sebastes levis) in U.S. waters north of 34 27 N. latitude (Point Conception). ......... 175 Appendix C. Decision Tables with P* = 0.4 and P* = 0.3. ............................ 183 Executive Summary Stock This is an assessment of Sebastes levis (“Cowcod”) in the Southern California Bight (SCB), defined as U.S. waters off California and south of Point Conception (34° 27' North latitude). Waters north and south of the SCB are not considered in the assessment