Distribution patterns of the argentine hake Merluccius hubbsi in San Matías Gulf as inferred from the fishing fleet activity and remote sensing data

OCAMPO REINALDO, MATÍAS; WILLIAMS, GABRIELA NOEMÍ; NARVARTE, MAITE; GONZÁLEZ, RAÚL; ESTEVES, JOSÉ LUIS; GAGLIARDINI, DOMINGO ANTONIO

Puerto Madryn

Workshop; SAC-D/ Aquarius Workshop; 2008

CONAE

A bottom trawl, multi-species fishery, occurs within San Matías Gulf (SMG; northern Patagonia), where the argentine hake is the most important resource in terms of landings and economical revenues. It has been demonstrated that the hake stock presents a regular inter-annual distribution pattern in the gulf, probably related to the phases of its biological cycle and the oceanographic conditions. The aim of this study was to infer the distribution patterns of the hake in SMG in relation to oceanographic processes. For this purpose, we compared fishery data of the bottom trawl fleet (hauls location and monthly yield per hour) gathered by a vessel monitoring system (SiMPO) and official records of landings, with a temporal series of sea surface temperature (SST), obtained by AVHRR sensor. Monthly data from both sources were grouped for the 2004-2006 period, to build up and overlap maps of fishing activity (hauls densities per km2) and SST averages. Satellite images showed that a thermal front was strongly structured annually in the gulf during spring-summer months, and the SiMPO records demonstrated that the fishing fleet coincidently operated on the thermal front area, obtaining the highest hake catches and yields there. These results revealed that the distribution pattern of the hake, as inferred by the dynamics of the bottom trawl fleet, and the thermal front are strongly associated, and suggest that it is feasible to use environmental data from remote sensing in studies on distribution patterns of bottom fishes.