MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
Composition and seasonal variation on the diet of South American sea Lion (Otaria flavescens).
SUAREZ, A. A.; SANFELICE, D.; CASSINI, M. H.; CAPPOZZO, H.L
THE LATIN AMERICAN JOURNAL OF AQUATIC MAMMALS
Lugar: Rio de Janeiro; Año: 2006
Diet seasonality in South American sea lions was studied using 252 scats from a male-exclusive haul-out site located in Puerto Quequén (38º37S, 58º50W) during 2001. Prey species were identified from hard remains and their relative importance was assessed considering frequency of occurrence and abundance. The main prey consumed by sea lions were fish (20 species), followed by cephalopods (four species) and crustaceans. The raneya, Raneya fluminensis, was the most frequent prey all year-round, and the most abundant one in autumn and winter. The Argentine anchovy, Engraulis anchoita, and the stripped weakfish, Cynoscion guatucupa, were the most abundant prey in spring and summer respectively. Seasonal differences in the sizes consumed were only found for stripped weakfish. The sea lions from Puerto Quequén showed a diverse diet, mainly feeding on demersal and pelagic prey. Our study fills a geographical gap of data on diet and interaction with fisheries of Southern sea lions. With it, there are studies along almost all their geographical range. Two main patterns emerged from these studies: (1) O. flavescens is a generalist and opportunist feeders, preying on a big rank of species, mainly those of pelagic and demersal habits, (2) the competition with fishery is not a generalized phenomenon but should be evaluated locally to estimate the impact of South America sea lions to this commercial activity in specific cases.