BAYESIAN LENGTH ANALYSIS AND EXPLOITATION RATES FROM THE MAIN TARGET SHARK SPECIES CAUGHT IN THE NORTHWESTERN MEXICAN PACIFIC: A PREAMBLE TO FISHERY INDICATORS

Análise de comprimento bayesiano e taxas de exploração das principais espécies de tubarão alvo capturadas no noroeste do Pacífico mexicano: um preâmbulo para indicadores de pesca

Abstract

Sharks in Mexico have economic, fishing, and social importance; however, there are no complete assessments of their populations, mainly due to scarce and inadequate catch and effort data. Nevertheless, through size frequency analysis, it is possible to obtain preliminary fishing indicators to know the status of an exploited population. This study analyzes fishing- dependent data (sizes and sexes) of nine species of pelagic sharks from data collected onboard medium-size shark vessels in the Mexican Pacific from 2006 to 2018. Our results suggest that the average lengths in the catch have remained constant throughout the study period. Similarly, exploitation rates remained below the benchmarks proposed by the literature. However, the results presented in this study should be taken cautiously and only as a preliminary analysis until more complete studies are carried out.

Keywords: bayesian approach, Mexican Pacific, pelagic sharks, total mortality.