Seals and sea lions

10 species of seals and sea lions occur in Australian waters. Of these, three are commonly found in southern Australian waters and the remainder occur in Australia's Antarctic Territory.

Many seal and sea lion populations declined significantly in the 18th and 19th Centuries due to indiscriminate harvesting and, although most populations have recovered, some remain at low levels. Current threats to seals and sea lions in Australian waters include interactions with commercial fishing operations and exposure to harmful marine debris.

Three species of seal and sea lion are currently listed as threatened by the Australian Government.

Government action

Environment Protection and Biodiversity Conservation Act 1999

Under the EPBC Act all seals and sea lions occurring within Australian waters are listed as marine species (EPBC Act 1999; section 248). It is an offence to kill, injure, take, trade, keep, or move any member of a listed marine species on Australian Government land or in Commonwealth waters without a permit.

Where these animals occur in state jurisdictions relevant state legislation applies.

Threatened status

Three species of seal are also listed under the EPBC Act as Vulnerable (section 178), which provides additional protection. These species are:

  • the sub-Antarctic fur seal (Arctocephalus tropicalis)
  • the southern elephant seal (Mirounga leonina) and
  • the Australian sea lion (Neophoca cinerea).

Besides a range of protective measures also afforded to marine species (see above), the EPBC Act requires that any action that has, will have or is likely to have a significant impact on a threatened species must be referred to the Department of the Environment for assessment before the action goes ahead.

Recovery plan

Under the threatened species legislation, listed threatened species can have a recovery plan made in order to guide actions to help the species recover. Of the three listed seals in Australian waters, the Australian sea lion has a recovery plan.

Antarctic Treaty

Seals located south of 60°S are protected under the Antarctic Treaty (Environment Protection) Act 1980 and associated conventions including the Seals Convention.

Of the seal species found in Australian waters, only the Australian sea lion and the Australian and New Zealand fur seals occur on the Australian mainland and in Tasmanian waters. The others, including the threatened leopard seal and southern elephant seal are found in Australia's Antarctic Territories.

Seals found in Australian Waters

Seals, sea lions and walruses are marine mammals and belong to the order pinnipedia. There are 33 species of pinnipeds, divided into three families. The family otariidae contains 14 species, including the fur seals and sea lions. Otariid species are typically more upright when on land, and can move with reasonable agility. The family phocidae is made up of the 'true seals' and contains species such as the leopard seal and the southern elephant seal. Unable to 'walk' on land like the otariids, the phocidae move in a lunging caterpillar-like motion. The third family, odobenidae, contains only the walrus.

Species regularly recorded in Australian waters
Family Common name Scientific name
Otariidae Australian sea lion Neophoca cinerea
New Zealand fur seal Arctocephalus forsteri
Australian fur seal Arctocephalus pusillus doriferus
Antarctic fur seal Arctocephalus gazella
Sub-Antarctic fur seal Arctocephalus tropicalis
Phocidae Southern elephant seal Mirounga leonina
Leopard seal Hydrurga leptonyx
Crab-eater seal Lobodon carcinophagus
Weddell seal Leptonychotes weddellii
Ross seal Ommatophoca rossii

Breeding sites

The Australian sea lion, New Zealand fur seal and Australian fur seal breed on the southern Australian coastline and its near shore islands. The remaining species breed on Antarctic pack-ice or sub-Antarctic Australian territories, and occasionally haul out on southern Australian beaches or reefs.

Seals breed on land or on ice, with peak mating and pupping taking place in the summer months for most species. However, the Australian sea lion is something of an exception as it has a 18 month asynchronous breeding cycle, meaning that it can pup in any month of the year and that month changes over time. Seal pups usually become independent from their mothers at ages varying from 10 weeks to about a year and a half for Australian sea lions.

Diet

Diet differs between species but usually includes squid and fish and, for Antarctic species, krill. Some seals, like the leopard seal, are known to eat seabirds such as penguins, and even other seals.

Threatening processes

Seals were hunted in Australia in the last century for their meat, oil and fur. By 1820, seal populations had been reduced to remnants. Some breeding colonies, such as the Australian sea lion colonies in Bass Strait, were completely destroyed. Today, all seals are protected in Australian waters and populations of some species are recovering from this over-harvesting.

However, some species of seal remain threatened by human activities, particularly from interactions with commercial fishing operations and entanglement with fishing gear and other debris. Other potential threats include a reduction in food supply; human disturbance; oil spills and chemical contaminants and disease. Seismic survey activity and climate change may also impact on seals, although little is known about the effects of these at this time.

Where to see seals

There are many places along the coastline of southern Australia where seals can be seen in the wild. Visitors must take a great deal of care not to disturb seals as this may interfere with their efforts to feed their young. Some seals can also move quickly overland and may bite if harassed. Some of the best places where organised viewing of seals takes place include Seal Bay on Kangaroo Island, Montague Island on the New South Wales South Coast, Seal Rocks in Victoria, various places in Tasmania and on accessible islands around Perth and Albany in Western Australia.

Resources

Books & reports

Links