Fatty acid composition suggests leopard seals are no longer apex predators in the Western Antarctic Peninsula ecosystem

GUERRERO ALICIA; NEGRETE JAVIER; MÁRQUEZ MARÍA E.I.; MENNUCCI JORGE.A; ZAMAN KATHERIN.; ROGERS TRACEY. L

Auckland

Conferencia; XXXIII SCAR Biennial Meetings and Open Science Conference; 2014

SCAR

The leopard seal is a top predator that feed on a wide variety of prey. Nevertheless, during the last decade, studies have revealed, via scat content1 and stable isotope analyses, that Antarctic krill has become their main prey in the Western Antarctic Peninsula.To establish the degree of Fatty acid stratification of the leopard seals blubber and its implications for dietary analysis and to determine the diet composition of leopard seals in Western Antarctic Peninsula using FA analysis of blubber. Stratification of leopard seal blubber is similar to pattern seen in other marine mammals 5,6 with higher levels of MUFA in the outer layer and increasing values of SFA in the inner layer.Fatty acid comparison with prey species supports the hypothesis of a dietary function of the inner layer, which is closer to prey types than the outer layer. The inner blubber layer resembles better the diet composition of leopard seals. Leopard seals from Western Antarctic Peninsula are feeding mainly on Antarctic krill.