Latin american journal of aquatic research
versión On-line ISSN 0718-560X
ROMERO, María Alejandra et al. Trophic overlap between the South American sea lion Otaria flavescens and the demersal trawl fishery in San Matías Gulf, Patagonia, Argentina. Lat. Am. J. Aquat. Res. [online]. 2011, vol.39, n.2, pp. 344-358. ISSN 0718-560X. http://dx.doi.org/10.4067/S0718-560X2011000200016.
As world fisheries began to decline and massive collapses were observed, the competition between marine mammals and fisheries became an issue of growing concern. San Matías Gulf (Patagonia, Argentina) is considered to be a fishery ecosystem independent of the Argentine Continental Shelf waters, with particular oceanographic and biological properties. As a semi-enclosed ecosystem, this gulf may generate particular scenarios for interactions between the demersal trawl fishery fleet and the population of South American sea lions Otaria flavescens. In this paper, the diet of the top predator and the composition of fishery catches were characterized in order to assess the trophic overlap between these two components. This analysis and a comparison of the sizes of prey consumed revealed a low probability of competition for similar resources between the fishing fleet and the marine mammals in the San Matías Gulf ecosystem.
Palabras clave : Otaria flavescens; sea lion; San Matías gulf; trawl fishery; trophic overlap; Patagonia; Argentina.