22nd Regular Session of the Scientific Committee

SC22 will evaluate three spatial options for the bigeye MP forwarded by BMW01 for further consideration:

• 20°N–10°S tropical longline;

  • Convention Area-wide longline catch limit; and

  • 20°N–10°S tropical longline excluding the Hawaii longline fishery. 

SC22 discussions will also focus on resolving key design and implementation elements, including:

• selection among the agreed spatial options;

  • fisheries and fleets to be covered;

  • interpretation and application of candidate TRPs;

  • HCR structure and mixed-fishery burden sharing;

  • treatment of fisheries outside MP control and overlap-area implementation;

  • practical implementation of MP outputs within existing CMMs and the Tropical Tuna Measure framework; and

  • evaluation of candidate MPs and associated performance trade-offs.

• The development of the bigeye tuna Management Procedure (MP) is at a critical design stage, with adoption targeted at WCPFC23 in December 2026 under WCPFC22 guidance. 

  BMW01 agreed that the overlap area should be treated as an implementation adjustment rather than as a direct MP output, and that fisheries managed through the BET MP would depend on the selected spatial range. BMW01 also agreed that SPC should proceed with further evaluation of the three WCPFC21 candidate TRPs using a 50% probability formulation, and that the BET MP should use a three-year management period with a two-year data lag. 

  BMW01 agreed that SPC should evaluate a Hillary Step-style HCR for the BET MP and proceed using longline catch limits as the longline output control and purse seine FAD closure periods as the purse seine output control. BMW01 noted that the longline output should be expressed as catch, particularly where the MP spatial range covers the full Convention Area, while implementation arrangements may continue using effort-based approaches such as the VDS in some fisheries. BMW01 also requested SPC to evaluate a broader range of purse seine FAD closure/open period options beyond the current 0-3 month range and to further clarify how longline catch scalars translate into absolute catch limits under different parts of the HCR.