Variabilidad en la estructura poblacional del calamar gigante (Dosidicus gigas) en Santa Rosalía, región central del Golfo de California = Variability in the population structure of jumbo squid (Dosidicus gigas) in Santa Rosalía, central Gulf of California

Abstract

This study describes the population structure of jumbo squid (Dosidicus gigas) in the area of Santa Rosalía (central Gulf of California) during the years 2003 and 2004, and analyzes the interannual variability in the size structure over a wider time period, 1996-2004 (except 2000-2002). The results revealed clear differences in the size structure and sexual maturity of males and females between 2003 and 2004. The jumbo squid population observed during the 2003 fishing season showed a high proportion of large and sexually mature individuals, whereas most specimens sampled during 2004 were smaller and immature. Expanding our time period, we observed a strong interannual variability in the size structure of jumbo squid within the Gulf of California, which was also reflected in the size at maturity. These changes in the population structure seem to be related to the occurrence and intensity of El Niño events. We recommend taking this variability into account at the beginning of each fishing season when the authorities establish the management strategy for the jumbo squid fishery in the Gulf of California