The diet of the Antarctic fur seal Arctocephalus gazella at the South Orkney Islands in ten consecutive years

JUÁRES M.; CASAUX R.; CORBALAN A.; CARLINI A.

POLAR BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2016 vol. 39 p. 1197 - 1206

0722-4060

AbstractTo improve theknowledge on the foraging behavior of the Antarctic fur seal, evaluate ifchanges in its diet are associated to changes in prey availability, and evaluateif the fisheries negatively interacted with this seal, a total of1359 scats of non-breeding maleswere collected in ten consecutive sampling periods between 1994 and 2003 at Laurie Island, South Orkney Islands. Theanalysis of the samples indicated that theAntarctic krill was the most numerous prey throughout the sampling periodfollowed in importance by fish prey. Antarctic krill also predominated byreconstructed mass, except during 1994and 1998 whenpenguins were the most important prey, and during 1995 when fish did. Among fish, demersal-benthic species (mainly Gobionotothen gibberifrons, Chaenocephalus aceratus and Chionodraco rastrospinosus)dominated in the diet except in 1997, 1998, 1999 and 2002 when myctophids(mainly Gymnoscopelus nicholsi and Electrona antarctica) werethe most important fish prey. In seasons when fish dominated the diet, the dietwas primarily comprised of demersal species. Although our results are inoverall agreement with previous studies, the contribution to the diet of themain preys changed throughout the sampling period probably in parallel withchanges in prey abundances. According to our information on fish consumption, thefisheries carried out in the past around the South Orkney Islands negativelyinteracted with seals.