Pacific Islands Fisheries Science Center (U.S.)

The data provided to the ISC Billfish Working Group for the 2018 swordfish stock assessment in Stock Synthesis are summarized. An analysis of the Western Central North Pacific stock area standardized CPUE was performed to investigate potential conflict and correlations using the FLCore package. When there were multiple time periods of standardized CPUE indices for a fleet, they were combined into a single time series for this analysis. The results show moderate positive correlations between most indices. The highest positive correlation was between the US longline shallow set index and Taiwanese longline (0.76). There were five negative correlations, the largest of which was between the Taiwan longline and Japan longline area 1 indices (-0.33). Overall, there were not substantial conflicts in the CPUE time series, and all indices should be considered for inclusion in the Stock Synthesis base-case model.

http://doi.org/10.7289/V5/WP-PIFSC-18-002

Working Paper