STANDARDIZATIONS OF CPUE OF BLUE MARLIN AND WHITE MARLIN CAUGHT BY JAPANESE LONGLINERS IN THE ATLANTIC OCEAN

SUMMARY Blue marlin (Makaira nigricans) and white marlin (Tetrapturus albidus) are caught as by-catch species in the Japanese longline fishery that operates in the Atlantic Ocean. Significant changes in gear configuration and main fishing grounds that have occurred since the fishery started in 1956 make it difficult to standardize CPUE by a generalized linear model (GLM) incorporating information about gear configuration. Recently, a new method that uses behavioral constraints of the target species, together with environmental data, to better define effective fishing effort, was developed for CPUE standardization. This new approach is applied to the Japanese catch and effort data of Atlantic blue and white marlins to investigate ways for improving the estimation of abundance indices. Comparisons are made against abundance indices obtained with the GLM standardization approach. RESUMEN