The Salish Sea Marine Survival Project: Understanding salmon survival

Session description: SPECIES 6: The Salish Sea Marine Survival Project: Understanding salmon survival Over the past 30‐40 years, marine survival of Chinook, coho, and steelhead populations in the Salish Sea has declined precipitously, and total abundance today remains well below 1970s‐1980s abundances. Historically, our understanding of what drives salmon and steelhead survival in saltwater has been limited. In response to this need, Long Live the Kings (U.S.) and the Pacific Salmon Foundation (Canada) developed a comprehensive transboundary approach to determine the primary factors affecting salmon and steelhead survival in the Salish Sea. The Salish Sea Marine Survival Project (SSMSP; www.marinesurvivalproject.org) brings together multidisciplinary international expertise from over 60 U.S. and Canadian agencies, Tribes and First Nations, academia, and non-profit organizations. The project's integrated, ecosystem‐based research framework incorporates coordinated data collection and standardization, information sharing, and international collaboration to better understand population dynamics within the Salish Sea ecosystem, improve forecasting and management, and aid recovery. The research phase of the Project is 2014‐2018; it culminates with a focus on converting research results into conclusions and management actions. The presentations within this session built towards a better understanding of salmon survival in the Salish Sea, from individual fish tracking to end-to-end ecosystem models. Presenters discussed population-specific contaminant impacts and effluent exposure through outmigration, declining eelgrass condition and increasing shoreline structure in the Strait of Georgia, commonalities in survival patterns across chinook salmon, coho salmon, and steelhead, and effects of migration routes, pathogen loads, and density of conspecifics at marine entry on survival. An end-to-end ecosystem model of Puget Sound is currently being created to simulate trophic dynamics, fisheries, nutrient dynamics, microbial cycles, and habitat. This model is intended to evaluate the strength of evidence for hypotheses around declining chinook, coho, and steelhead survival, and can facilitate development of ecosystem-based management strategies.