Consideration of Exceptional Circumstances for the Bigeye Tuna MP 2023

The IOTC adopted the bigeye tuna management procedure (MP) in 2022, which is used to recommend the Total Allowable Catch (TAC). As part of the MP schedule, the Commission has adopted an annual review of evidence for exceptional circumstances, to check for conditions that could make the implementation of the TAC advice risky to the stock or fishery.
The Exceptional Circumstances Guidelines specify a three-stage process: (i) examining evidence for exceptional circumstances, (ii) determining severity and impact, and (iii) recommending any management or research action that should be taken. A wide range of information is reviewed to examine if there is evidence for exceptional circumstances, e.g., changes in the knowledge of stock or fishery uncertainties against which the MP was tested. The Exceptional Circumstances Guidelines (IOTC–2021–SC24 Appendix 6A) provide a scientific process for developing appropriate management responses to exceptional circumstances and, hence, provide transparency in TAC decision-making by the Commission.
The MP was run in 2022. Changes in the data used in the CPUE standardisation, a new growth curve and an alternative natural mortality scenario used in the 2022 stock assessment models were items identified as potential exceptional circumstances in 2022. Severity and impact were considered low for these items and no actions were recommended. No new exceptional circumstances were detected in 2023, and therefore, no research or management actions are recommended.