Standardized CPUE of shortfin mako, Isurus oxyrinchus, based on data gathered by the national observer program on board the Uruguayan longline fleet (2001-2012)

This study presents the standardized catch rate of shortfin mako shark, Isurus oxyrinchus, caught by the Uruguayan longline fleet in the Southwestern Atlantic using information from national onboard observed program between 2001 and 2012. Because of the large proportion of zeros catches (23%) the CPUE (catch per unit of effort in weight) was standardized by Generalized Linear Mixed Models (GLMMs) using a Delta Lognormal approach. The independent variables included in the models as main factors and first-order interactions in some cases were: Year, Quarter, Area, Sea Surface Temperature and Gear. A total of 1,706 sets were analyzed. Standardized CPUE showed an apparent increasing trend during the last six years of the study period.