VARIACIÓN DE LA DISTRIBUCIÓN Y BIOMASA DEL CALAMAR GIGANTE Dosidicus gigas (D´ORBIGNY, 1835) EN LA REGIÓN CENTRAL DEL GOLFO DE CALIFORNIA

Abstract

Mexico is the second largest producer of jumbo squid in the world, reports higher annual catches to 50,000 t in recent years. Historically it has been observed significant declines in the abundance of this resource (eg in 1998) and attributed to large-scale environmental events (ENSO) that may affect the availability of this species, but this hypothesis has not been proven. The aim of this study is to determine the variation in the distribution and biomass of giant squid in the central Gulf of California and its relation to environmental variables. Were obtained from nine research cruises carried out from 1997 to 2008. In each cruise were caught squid and sampling to record the sex, maturity and size. We estimated the total biomass cruise by two different methods. We performed an exploratory analysis of trends in distribution and giant squid in relation to various environmental variables through regression trees. The results indicate that the biomass ranged from 1.540 (November 1997) to 430.080 t (February 2003). The distribution of catches varied among cruises, immature agencies focused primarily on the west coast of the Gulf while mature were loaded to the East Coast. The small size squid were concentrated away from both coasts south of the Gulf and larger size were distributed near both coasts. Primary productivity and depth were the environmental variables that explained the distribution of catches and mature organisms. Upwelling may be an indicator of the biomass of squid that are recruited to the fishery. We conclude that the distribution and squid biomass changes over time and these variations may be explained by environmental factors.