Food of Weddell Seals at McMurdo Sound, Antarctica

Abstract

Stomach contents of 44 Weddell seals taken at McMurdo Sound, Antarctica, were examined. Fishes occurred in 97% of the stomachs that contained any food. Mysids, decapod crustaceans, amphipods and cephalopods were the in- vertebrate prey taken most frequently. All specimens examined were heavily in- fested with nematodes and cestodes, a condition related to the predominantly fish diet of this seal. INTRODUCrION During field studies of marine benthic invertebrates at McMurdo Sound, 1958 to 1961, the stomach contents of 44 adult Weddell seals, Leptonychotes weddelli (Lesson), were examined. This report describes the items of food taken by these seals and discusses these data in terms of published knowledge of the food habits of this species. Of the four truly Antarctic pinnipeds, the Weddell seal occurs farthest south. Its principal habitat is the fast sea ice or grounded ice along the coast. The species is circumpolar (Scheffer, 1958) and is found throughout the year near the United States McMurdo Station (77?51' S, 166?39' E) at McMurdo Sound in the southwestern Ross Sea. During the summer in this region seals use open leads and holes in the sea ice. In winter they live beneath the ice and utilize small blow holes or air in pockets under pressure ice. Although considerable literature relates to Antarctic seals there is much to learn of the ecology of individual species (Turbott, 1952, 1956; Gilmore, 1961). For information about the Weddell seal at McMurdo Sound, the best general source remains Wilson's (1907) account. To date, however, there has been little specific information available on the food habits of this species. ABSTRACT: Stomach contents of 44 Weddell seals taken at McMurdo Sound, Antarctica, were examined. Fishes occurred in 97% of the stomachs that contained any food. Mysids, decapod crustaceans, amphipods and cephalopods were the in- vertebrate prey taken most frequently. All specimens examined were heavily in- fested with nematodes and cestodes, a condition related to the predominantly fish diet of this seal. INTRODUCrION During field studies of marine benthic invertebrates at McMurdo Sound, 1958 to 1961, the stomach contents of 44 adult Weddell seals, Leptonychotes weddelli (Lesson), were examined. This report describes the items of food taken by these seals and discusses these data in terms of published knowledge of the food habits of this species. Of the four truly Antarctic pinnipeds, the Weddell seal occurs farthest south. Its principal habitat is the fast sea ice or grounded ice along the coast. The species is circumpolar (Scheffer, 1958) and is found throughout the year near the United States McMurdo Station (77?51' S, 166?39' E) at McMurdo Sound in the southwestern Ross Sea. During the summer in this region seals use open leads and holes in the sea ice. In winter they live beneath the ice and utilize small blow holes or air in pockets under pressure ice.