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

The conservation and management of Pacific salmon in Canada faces an uncertain future. While fisheries policies, like Canada's 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 from 1980 to 2020 to determine population status, assess risks from mixed-stock fisheries spanning U.S., Canadian, and Indigenous jurisdictions, and implemented forward simulations of alternative productivity and harvest scenarios to inform collaborative management. Since 2017, we found productivity shifts associated with marine heatwaves led to a 37% decline in coho abundance and 40%–69% of populations falling below biological reference points. Although long-term coho recovery depended on future productivity trends, reduced harvest across U.S. and Canadian fisheries can improve short-term recoveries. 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.