Salish Sea Marine Survival Project

5 PREDATION STUDIES: Predators are a major source of mortality on juvenile Chinook and Coho Salmon in the Salish Sea. Our research demonstrated the significance of harbour seals and birds as juvenile salmon predators, and that habitat conditions can significantly increase exposure to predators, particularly in disrupted estuaries associated with log booms. We recommend the development of management actions to reduce exposure of juvenile salmon through habitat restoration, water flow regulation, and removal of log booms in estuaries. PATHOGENS AND DISEASE: The southern Strait of Georgia has been identified as an infection 'hotspot' for Pacific Salmon during summer months, with higher infection overall in the Strait of Georgia as compared to the outer Pacific coast. The presence of a dozen pathogens has been associated with poorer body condition and survival for Chinook, Coho, and Sockeye salmon (50 different pathogens were documented in BC salmon). This study was also the first to demonstrate the presence of Piscine orthoreovirus (PRV ) and associated diseases in BC's aquaculture salmon (Atlantic and Chinook Salmon). However, the risk that PRV presents to BC's wild Pacific Salmon continues to be debated. PSF has supported a move to closed containment salmon aqua- culture in BC, based on outcomes of this research and the present state of Pacific Salmon in BC. Under projections for climate change, we recommend continued research into pathogens and disease as a source of mortality, and tools developed during the Strategic Salmon Health Initiative may be invaluable to these studies. The ultimate goal of the SSMSP has been to determine whether weak Chinook, Coho and steelhead survival is locally or globally driven and to develop action-oriented research and management recommendations. The complex and highly-migratory life history of Pacific Salmon makes resolving the primary determinants of their marine survival difficult — particularly as humans have extensively altered every habitat they depend upon. We have developed a broad list of recommended actions and next steps to address local impacts but it also appears likely that much of the variation in salmon production is driven by annual variation in weather and resulting biological oceanographic conditions in the Salish Sea. Resource managers will need to monitor interannual changes in marine conditions for salmon and respond effectively as required. In summary, the Salish Sea Marine Survival Project has made a significant contribution to understanding our wild Pacific Salmon, and should enable implementation of management actions to benefit Chinook and Coho Salmon production. Ultimately, these actions will benefit Pacific Salmon and marine diversity in Canada's Salish Sea. We hope the community networks developed to complete the Salish Sea Marine Survival Program will be sustained including the international partners crucial in this boundary sea. The Pacific Salmon Foundation thanks all those involved … the advisors, the researchers and financial supporters! 1. BC's Water Sustainability Act (2014) requires the implementation of minimum ecological flows to protect BC's fishery resources, but these flows remain undefined. 2 Those interested in further reading could see: Levings, C.D. 2016. Ecology of Salmonids in Estuaries around the World: Adaptations, Habitats, and Conservation. UBC Press, Toronto.

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