CESIMAR - CENPAT   25625
CENTRO PARA EL ESTUDIO DE SISTEMAS MARINOS
Unidad Ejecutora - UE
artículos
Título:
Sea lions (Otaria flavescens) from the end of the world: insights of a recovery
Autor/es:
GRANDI, M. FLORENCIA; SCHIAVINI, ADRIÁN C.M.; MILANO, VIVIANA N.; CRESPO, ENRIQUE.A
Revista:
POLAR BIOLOGY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2020 p. 695 - 706
ISSN:
0722-4060
Resumen:
To understand the recovery process and population dynamics of species that were severely depleted, it is essential to monitortheir population size and habitat changes throughout their distribution. The South American sea lion (SASL, Otariaflavescens) provides an opportunity to investigate the process of a reduction from sealing and the subsequent recovery in amarine mammal species. Its abundance was depleted throughout its distribution, but the most affected extraction areas werePenínsula Valdés (northern Patagonia) and Tierra del Fuego (Fuegian Archipelago). The aims of this work are to presentrecent estimates of the population abundance and then analyze changes in social composition, distribution, population sizeand trend of SASL at their sub-Antarctic distribution. We made an aerial survey of Fuegian Archipelago colonies and comparedthe results with historical compilation data registered since 1948. In total 49 colonies were surveyed (24 exclusive ofSASL, 15 shared with South American fur seals and 10 sites were abandoned). An abundance of 7684 individuals (including440 pups) was recorded. There was an increase of population abundance, with a change of the social composition anddistribution of some colonies through time. The average annual percentage of population changes yields a growth of 8.8%.This value completes the population growth trend data throughout Southwestern Atlantic for SASL, and shows that there isan increasing latitudinal gradient of these rates. We discuss possible explanations related to differences in the beginning ofthe recovery, or in reactions to local environmental constraints, or migration from Pacific stocks.