Assessment and Management of Pacific Herring in the Salish Sea: Conserving and Recovering a Culturally Significant and Ecologically Critical Component of the Food Web Prepared for: The SeaDoc Society Submitted by: The Salish Sea Pacific Herring Assessment and Management Strategy Team FINAL REPORT For award number 201701956-01 issued to Co-PIs Tessa Francis and Dayv Lowry August 2018 Members of the Salish Sea Pacific Herring Assessment and Management Strategy Team: Principle Investigator Tessa Francis, Puget Sound Institute, University of Washington, Tacoma Principle Investigator Dayv Lowry, Marine Fish Science Unit, WDFW, Olympia Todd Sandell, Marine Fish Science Unit, Forage Fish, WDFW, Mill Creek Kelly Biedenweg, Oregon State University, Corvallis Evelyn Brown, Lummi Indian Tribe Jaclyn Cleary, Fisheries and Oceans Canada Phill Dionne, Marine Fish Science Unit, Forage Fish, WDFW, Olympia Timothy Essington, University of Washington, Seattle Correigh Greene, Northwest Fishery Science Center, National Oceanic and Atmospheric Administration Lorenz Hauser, University of Washington, Seattle Doug Hay, Fisheries and Oceans Canada, retired Paul Hershberger, United States Geological Survey, Marrowstone Marine Field Station Anna Kagley, Northwest Fishery Science Center, National Oceanic and Atmospheric Administration Tim Kulchyski, Cowichan Tribes Paul McCollum, Port Gamble S’Klallam Tribe Chad Ormond, Q’ul-lhanumutsun AQuatic Resources Society Manuscript may be cited as: The Salish Sea Pacific Herring Assessment and Management Strategy Team. 2018. Assessment and Management of Pacific Herring in the Salish Sea: Conserving and Recovering a Culturally Significant and Ecologically Critical Component of the Food Web. The SeaDoc Society, Orcas Island, WA. 74 pp. Table of Contents I. Executive Summary .............................................................................................................................. 6 II. Introduction ............................................................................................................................................. 9 III. Cultural and socioeconomic significance of Pacific herring in the Salish Sea ........................................ 11 IV. Stock Structure ...................................................................................................................................... 13 V. Fisheries Management ........................................................................................................................... 17 A. British Columbia/Strait of Georgia ................................................................................................. 17 B. Washington State ........................................................................................................................... 19 VI. Status and Trends .................................................................................................................................. 20 A. Southern Salish Sea distribution and abundance summary ........................................................... 20 B. Northern Salish Sea distribution and abundance summary ........................................................... 22 VII. Factors affecting herring distribution and abundance ......................................................................... 23 A. Anthropogenic stressors ................................................................................................................ 23 1. Exploitation ................................................................................................................................ 23 2. Water Quality .............................................................................................................................. 23 3. Toxics .......................................................................................................................................... 25 4. Vessel Noise ............................................................................................................................... 27 5. Nearshore light pollution ........................................................................................................... 28 6. Habitat degradation and destruction ......................................................................................... 29 B. Population Factors ............................................................................................................................ 30 C. Food web interactions .................................................................................................................... 32 1. Predation .................................................................................................................................... 32 2. Competition ................................................................................................................................ 35 3. Disease ....................................................................................................................................... 39 D. Physical and broad-scale environmental factors ............................................................................ 40 1. Climate Change .......................................................................................................................... 40 2. Ocean acidification ..................................................................................................................... 41 VIII. Summary of key data gaps and uncertainties ..................................................................................... 44 IX. Analytical decision support tools .......................................................................................................... 46 A. EcoPath ........................................................................................................................................... 46 B. Atlantis ........................................................................................................................................... 47 C. Management strategy evaluation .................................................................................................. 47 D. Qualitative network models ........................................................................................................... 47 X. Potential management and conservation actions .................................................................................. 50 3 A. Reduce fishing effort ...................................................................................................................... 50 B. Reduce predation ........................................................................................................................... 51 1. Pinnipeds .................................................................................................................................... 51 2. Seabirds ...................................................................................................................................... 52 3. Jellyfish ....................................................................................................................................... 52 C. Habitat Restoration ........................................................................................................................ 52 D. Reduce nearshore stressors ........................................................................................................... 52 1. Light pollution ............................................................................................................................ 52 2. Small vessel activity .................................................................................................................... 53 E. Improve water quality .................................................................................................................... 53 1. Toxics .......................................................................................................................................... 53 2. Nutrients .................................................................................................................................... 54 F. Manage shipping traffic .................................................................................................................. 54 1. Noise ........................................................................................................................................... 54 2. Oil spill risk ................................................................................................................................. 54 G. Population Interventions ................................................................................................................ 54 1. Transplant herring eggs to increase survival .............................................................................. 54 2. Artificial Production of Forage Fish ............................................................................................ 55 3. Modify hatchery salmon release timing ..................................................................................... 56 XI. Acknowledgements ............................................................................................................................... 56 XII. References ...........................................................................................................................................