22nd Regular Session of the Scientific Committee

SC22 will review results from initial MP evaluations across the spatial options, candidate TRPs, HCR structures, and mixed-fishery control arrangements, taking into account guidance from SC21 and the outcomes of BMW01. SC22 will review the evaluation results and provide technical advice to the Commission on the performance, trade-offs, and consistency of candidate management procedures with agreed management objectives and risk criteria, including identification of any candidate MPs that may not satisfy agreed risk thresholds such as the LRP risk threshold.

• The evaluation of candidate bigeye tuna management procedures represents the transition from design to performance testing within the MSE framework, where alternative MPs are assessed against agreed performance indicators across the range of uncertainties represented in the operating model grid. 

  BMW01 agreed that SPC should use the following candidate performance indicators for BET MP evaluations:

  • stock status in the WCPFC-CA (SB/SBF=0);

  • proximity to the TRP;

  • probability that SB/SBF=0 is below the LRP;

  • expected BET catch;

  • expected vulnerable biomass for LL fisheries;

  • catch and effort variability;

  • F relative to FMSY; and

  • MSY. 

• Particular attention is expected on MP performance under key uncertainties, including recruitment variability, mixed fishery interactions, assumptions regarding fisheries outside MP control, overlap-area implementation issues, and sensitivity to design choices such as HCR structure, output controls, and treatment of FAD-related measures. Evaluations are also expected to examine trade-offs associated with alternative burden-sharing arrangements between tropical longline and purse seine fisheries, including stability, vulnerable biomass outcomes, catch variability, and risk performance across alternative management configurations.