Climate, Competition and Aquaculture Impacts on the Dynamics of Fraser River Sockeye Salmon and the Economics of Their Fisheries

Climate, competition and disease are well-recognized drivers of population dynamics, which can be intertwined by animal migrations. Sockeye salmon from the Fraser River are one of the most ecologically, economically and socially important salmon complexes in Western North America. Changes in oceanographic conditions, competition with other salmon for food and exposure to farmed salmon may in combination contribute to declines in Fraser sockeye productivity. We used empirically based simulation modeling of Fraser sockeye salmon populations to explore how plausible future changes in climate, competition and aquaculture may affect sockeye populations and associated commercial fishing effort, catch and profits. Our findings highlight that declines in productivity and profits are predominately driven by competition, which can be magnified by exposure to open net-pen aquaculture and compensated by climate change. These analyses provide a bioeconomic framework for informing policy and management of farmed, hatchery and wild salmon in a changing ocean with finite resources. In addition, our findings highlight the importance of considering how interactions among climate, competition and aquaculture may influence the coastal economies and ecosystems that depend upon salmon.