Patrones espaciales de cardúmenes poliespecíficos en la pesca del atún en el Océano Pacífico Oriental

Abstract

The activities of the Mexican tuna fleet in the East Tropical Pacific (ETP) were analized in order to define the spatial patterns of the tuna and associated species. The data used was obtained through the scientific observers of the Programa Nacional de Aprovechamiento del Atún y Protección de Delfines, during 1992. This information consist of records of species sightings, other signs (breezes, floating objects), environmentl variables and fishing sets. The signs were registered regularly or during fishing activities. Three zones were defined: north, central and south. In the north zone predominated the free school sets, marine mammals and birds sightings. The central zone showed a high frequency of dolphin sets, marine mammals and birds sightings. The south zone doesn't have a defined sighting pattern; however, it is noted a slightly high proportion of floating objects sets (log-sets). The zones coincide with the dominant water masses of he ETP. Regarding the presence of species registered in each zone, differences in their frequencies were founds. It is concluded that there is a great heterogeneity in the ETP, which is reflected in the distribution of species groups.