21st Regular Session of the Scientific Committee

SC21 will review the results of the oceanic whitetip shark stock assessment, building on the Phase 1 outcomes endorsed by SC20, which included data compilation, fishery characterization, and catch reconstruction. The assessment now includes updated longline catch and abundance indices based on recent observer data, and applies both an integrated model (Stock Synthesis) and a dynamic surplus production model, as recommended. 

SC21 will assess key elements, including the treatment of time-varying release mortality, parameter specifications (such as stock-recruit relationships), the incorporation of fate modeling, and the sensitivity of length-frequency data modeling. Additional focus will be placed on refining CPUE indices, addressing data gaps (e.g., right-tail sensitivity), and evaluating uncertainty in population estimates from earlier time periods. 

SC21 will provide scientific advice on model results and assumptions, confirm a base case model for 2025, and consider the use of alternative formulations and historical data to improve stock size estimation and projections.