Spring and summer predation on fish by the Antarctic fur seal, Arctocephalus gazella, at King George Island, South Shetland Islands

Abstract

The fish component of the diet of nonbreeding male Antarctic fur seals, Arctocephalus gazella, was analyzed from 70 scats collected at Stranger Point, King George Island, South Shetland Islands, during the austral spring (n = 36) and summer (n = 34) of 1993-1994. Fish occurred in approximately 70% of scats that contained food remains irrespective of season. In spring, the main fish prey were Electrona antarctica, Pleuragramma antarcticum, and Notolepis coatsi, which together gave two-thirds of the 110 otoliths recovered. In summer, 457 otoliths were retrieved; the most frequent and abundant species were Gymnoscopelus nicholsi, E. antarctica, and P. antarcticum, which represented over 80% of the otoliths recovered. A substantial increase in the amount of fish ingested by fur seals occurred from spring to summer concomitant with a change in the relative proportion of fish taxa. Most fish species identified are pelagic and feed on krill. During the study period, commercial fishing in the area was not based upon any of the fish species identified.