Marine fronts are important fishing areas for demersal species at the Argentine Sea (Southwest Atlantic Ocean)

ALEMANY, D.; ACHA, E. M.; IRIBARNE, O.

JOURNAL OF SEA RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014

1385-1101

The high primary and secondary production associated with frontal systems attracta diversity of organisms due to highprey availability; this is why a strong relationship between fronts and pelagic fisheries has been shown worldwide. In the Argentine Sea, demersal resources are the most important, both in economical and ecological sense; so we hypothesize that fronts are also preferred fishing areas for demersal resources. We evaluated the relationshipbetween spatial distribution of fishing effort and oceanographic fronts, analyzing three of the most important frontal systems located in the ArgentineSea: the shelf-breakfront, the southern Patagonia front and the mid-shelf front. Individual vessel satellite monitoring system data (VMS; grouped by fleet type: ice-trawlers, freezer-trawlers and jigging fleet) were studied and fishing events were identified. Fishing events per area were used as a proxy of fishing effort and its spatial distribution by fleet type was visualized and analyzed withGeographic Information Systems. Oceanographic fronts were defined using polygonsbased on satellite chlorophyll amplitude values, and the percentage of fishing eventswithin each polygon was calculated. Results showed a positive association betweenfrontsand fishing activities of the different fleets, which suggest the aggregation of target species in thesezones.The coupling of the freezer-trawler and jigging fleets (that operate on lower trophic levelspecies; Macruronus magellanicus and Illex argentinus respectively) with fronts was higher than the ice-trawler fleet, targeting species of higher trophic level (Merluccius hubbsi). Marine fronts represent important fishing areas, even for demersal resources, as the distribution of fishing fleets andfishing effort are positively associated with frontal zones.