Possible implications of no hydro‐acoustic survey estimate of biomass in November 2024 on the anchovy TAC in 2025

The impact of a single year’s missing November hydro‐acoustic survey estimate of South African anchovy biomass on the anchovy Total Allowable Catch (TAC) is investigated. This is done using the Management Strategy Evaluation that was used to develop OMP‐18rev which has been used to recommend TACs for South African anchovy since December 2021. Simulations indicate that a substitute biomass of approximately 65% of the average three preceding year’s survey estimates ‐ or 55% of the average of the 4th preceding year and two most recent preceding year’s survey estimates ‐ could be used to maintain a similar risk level to which OMP‐18rev was tuned. The initial TAC is simulated to be approximately 10% or 18% lower in median terms, respectively, than if a survey estimate were available.