Using fisheries risk assessment to inform precautionary and collaborative management in a declining coho salmon fishery

Abstract

The conservation and management of Pacific salmon in Canada faces an uncertain future. While fisheries policies, like Canadas Wild Salmon Policy, increasingly emphasize conservation, salmon continue to decline due to cumulative pressures of climate change, habitat loss, and overfishing, requiring precautionary management. We quantified population dynamics for 52 coho salmon populations along the North and Central Coast of British Columbia since 1980 to determine population status, assess risks posed by a mixed-stock fishery spanning U.S., Canadian, and Indigenous jurisdictions, and implemented forward simulations of alternative productivity trends and harvest scenarios to inform collaborative management tables. We found declining abundances for 51% of coho populations since 2017, driven by productivity regime shifts associated with recent marine heatwaves. Although long-term coho recovery depended on future productivity trends, reduced harvest rates across U.S. and Canadian fisheries can improve short-term recovery prospects. While rebuilding coho will depend largely on whether productivity improves, harvest management remains one of the few tools available to provide a safe operating space for coho populations, and their fisheries, to adapt to ongoing ecosystem changes.