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

Published in Journal of Sea Research, v. 87:56–67
Authors

Alemany, D., Acha, E.M. and Iribarne, O.
Publication year 2014
DOI https://doi.org/10.1016/j.seares.2013.12.006
Affiliations
  • Instituto de Investigaciones Marinas y Costeras (IIMyC Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Mar del Plata), CC 573 Correo Central, B7600WAG Mar del Plata, Argentina
  • Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Mar del Plata, Argentina

 
IAI Program

CRN3
IAI Project CRN3070
Keywords
Chlorophyll
Demersal Fish
Fishing Fleet
Frontal System
Squid
Trophic Level

Highlights

•A positive association between marine fronts and fishing activities is shown.

•Fleets operating on lower trophic level species showed higher coupling with fronts.

•Aggregation of target species is suggested in frontal zones.

•Marine fronts represent important fishing areas, even for demersal resources.

Abstract

The high primary and secondary production associated with frontal systems attract a diversity of organisms due to high prey 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 in ecological sense so we hypothesize that fronts are also preferred fishing areas for demersal resources. We evaluated the relationship between spatial distribution of fishing effort and oceanographic fronts, analyzing three of the most important frontal systems located in the Argentine Sea: the shelf-break front, 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 with Geographic Information Systems. Oceanographic fronts were defined using polygons based on satellite chlorophyll amplitude values, and the percentage of fishing events within each polygon was calculated. Results showed a positive association between fronts and fishing activities of the different fleets, which suggests the aggregation of target species in these zones. The coupling of the freezer-trawler and jigging fleets (that operate on lower trophic level species 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 and fishing effort are positively associated with frontal zones.