Catch level projections and management benchmarks in the face of nonstationarity—an application to Indian Ocean Yellowfin Tuna

Fisheries management relies on catch level projections developed from stock assessment models. Assumptions about future recruitment are highly influential when forecasting the catch levels that lead fisheries towards management objectives. Yet, there are not precise guidelines for configuring forward projections, and scientists around the world use different methods and assumptions. In this article, we review various assumptions made in fishery stock assessments to set up catch level projections. In addition, we identify an approach that matches recent stock dynamics with the projection period while maintaining the link between spawners and recruits. We recommend adjusting the equilibrium stock–recruitment relationship using the average recruitment deviations estimated during the last years of the assessment period. First applied to Indian Ocean Yellowfin Tuna in 2024, this approach was designed to handle recruitment trends and possible model misspecification. We consider this approach best suited for developing catch level projections from integrated stock assessments and conducting simulations in management strategy evaluation.