Crabeater Seal: where and when to see them

The crabeater seal is an Antarctic pack-ice specialist whose misleading name conceals a diet dominated by krill. Pale adults often rest on drifting floes, bringing them within distant deck-viewing range when ice and routes align. Their specialized teeth form an effective sieve for small prey. Although widespread around Antarctica, they depend on a changing sea-ice environment, and population estimates remain difficult because much of their habitat is remote and constantly moving.

Size

2.2–2.6 m long

Weight

200–300 kg

Lifespan

20–30 years

Status

Least Concern

Crabeater seals alternate feeding at sea with resting on pack ice, sometimes lying alone and sometimes in loose gatherings. During breeding, a female, her pup and an attending male may form a temporary group on a floe. Mothers nurse their pups for only a few weeks before weaning. Many adults bear long scars from leopard seal attacks survived when young, while killer whales are another important predator. Pups are born with a soft, woolly, light brown lanugo coat that is shed after a few weeks. These seals are known for their strong swimming ability and can cover considerable distances when foraging, often diving to moderate depths to feed on krill swarms.

• Its lobed cheek teeth function as a krill-retaining sieve.
• The common name does not describe its actual staple food.
• Many adults carry scars from leopard seal attacks earlier in life.
• Females give birth on sea ice rather than at permanent terrestrial rookeries.

November to March is the practical Antarctic visitor window for distant deck or occasional shore observations. Ice distribution and permitted routes govern opportunities, not a guaranteed seal season. The spring pupping period does not necessarily coincide with accessible or appropriate visitor viewing. The presence of suitable ice habitat for resting and molting is a key factor influencing their distribution, often dictating where they can be observed. While krill abundance is high during the austral summer, their distribution can be patchy, leading to local variations in seal numbers.

The species is strongly associated with Antarctic pack ice rather than permanent land-based colonies. Floating floes provide resting, moulting and breeding platforms near feeding waters. Shore observations are incidental where ice lies close to land; most practical viewing is from a distant vessel deck. Though generally avoiding land, individuals occasionally haul out on ice shelves or remote islands within their range. Their circumpolar distribution means they are found throughout the Antarctic pack ice zone, from coastal waters to the deep ocean.

Antarctic krill makes up the overwhelming majority of the diet, with small quantities of fish or other prey occasionally recorded. Multi-cusped cheek teeth interlock to retain krill while water escapes. Despite the common name, true crabs are not a normal dietary staple. Remarkably, crabeater seals possess the most complex teeth of any pinniped, specially adapted for filtering krill from vast quantities of water. An adult seal can consume several hundred kilograms of krill per day, making them one of the most significant krill consumers in the Southern Ocean.

Common name

Crabeater Seal

Scientific name

Lobodon carcinophaga

Animal group

Mammals

Size

2.2–2.6 m long

Weight

200–300 kg

Lifespan

20–30 years

Status

Least Concern

Identification

Its relatively slender muzzle and pale coat distinguish it from the blunt-faced Weddell seal and the much larger-headed leopard seal, although distant identifications can be difficult. Adult Crabeaters typically have a pale, often yellowish-white coat, which can appear quite clean after molting. Look for their distinctive elongated, somewhat 'dog-like' muzzle, which is a key distinguishing feature from other Antarctic seals.