Seasonal variation in the diet of Arctocephalus gazella at 25 de Mayo/King George Island, South Shetland Islands, Antarctica

The trophic study of Arctocephalus gazella is an essential tool for assessing its ecological role as a top predator of the Antarctic marine ecosystem. The aim of this study was to analyse its diet during an annual cycle. To our knowledge, this is the first report of the feeding habits of A. gazella during the winter period in the South Shetlands area. A total of 224 scats were collected in the winter 2004 and summer 2004/05 on the coasts of Stranger Point, Isla 25 de Mayo/King George. For the total study period krill was the main prey taxon, followed by fish, cephalopods and penguins. During summer, myctophids Gymnoscopelus nicholsi and Electrona antarctica and the nototheniid Pleuragramma antarcticum constituted the dominant fish prey species; in winter only P. antarcticum was dominant, while myctophids were absent.  The only squid species present in the diet was Slozarsykowia circumantarctica. It is concluded that fur seals centred their foraging activity on a krill community and fish associated with krill aggregations.