ANTARCTIC SEALS are truly fascinating marine animals and a signature species of the Southern Ocean. They can be found throughout the Antarctic region, with some species living farther south than any other mammal.
THE ANTARCTIC supports a much larger seal population than does the Arctic, in part because of the highly productive feeding areas that exist. Another reason is the lack of native predators such as polar bears, which also helps explain why seals in Antarctica show little fear of people. Of the six types of seals which are found south of the Antarctic Convergence, four of them are considered true Antarctic species: the Weddell, the Ross, the Crabeater and the Leopard. Both the Southern Elephant Seal and the Fur Seal do occasionally venture onto the continent, but prefer the more northerly islands of the warmer subantarctic seas.
SEALS WERE the first Antarctic species to be commercially harvested. In fact, it was the search for new populations of seals that led to much of the early exploration of Antarctica and the Southern Ocean. During the 19th and 20th centuries, several species of seals were heavily exploited for their skins or fur and for oil. Whole populations were decimated as early as the 1820’s and some, including the Antarctic Fur Seal, were driven to the brink of extinction. Today, seals in the Antarctic are protected by the Convention for the Conservation of Antarctic Seals, which nonetheless allows for a small quota of specific species to be taken for science.
THOUGH MOST of their time is spent in the water, all Antarctic seals, unlike whales, must return to land to breed. Breeding sites are found primarily on fast shelf ice and pack ice surrounding the Antarctic continent or on coastal shores of the more northerly islands. Breeding behaviors vary greatly among seal species. Ross, Weddell, and Leopard seals breed alone. Other species, such as the Antarctic Fur seal and the Southern Elephant seal prefer larger groups where dominant bulls aggressively defend ‘harems’ of females, with territorial disputes a common occurrence during breeding season.
ALL SEALS feed at sea using sonar (echolocation) and the enhanced sight of their large eyes. Diets vary but generally consist of krill (a key species in the Antarctic ecosystem), fish , and squid.
There are two main types of seals: the ‘eared’ seals (Otariidae) and the ‘true’ seals (Phocidae), which have no protruding ear. Only the Antarctic Fur Seal belongs to the Otariidae, or eared order. The ‘eared’ seals have hairless hind flippers that can be brought under their bodies making them very agile both on land and at sea. ‘True’ seals have furred hind flippers that they use to swim, but on land they are dragged behind the body in awkward ‘snakelike’ undulations.