Thursday, June 25, 2009

Seals and sea-lions

Seals, sea-lions and walruses 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 18 species. Unable to 'walk' on land like the otariids, they move in a lunging caterpillar-like motion. The third family, Odobenidae, contains only the walrus.

Seals in Australian Waters

The Australian sea-lion, New Zealand fur seal and Australian fur-seal breed on the coast of the Australian mainland (including Tasmania) and its nearshore islands. The remaining species breed on Antarctic pack-ice or Sub-Antarctic Australian territories, and occasionally haul out on Tasmanian mainland beaches or reefs.
Important Habitat

Important habitat for seals within the Australian jurisdiction comprises:

* breeding colonies of the terrestrial breeding species, Australian sea-lion, New Zealand fur-seal and Australian fur-seal, on the Australian coast;
* breeding colonies of the terrestrially breeding species, Antarctic fur-seal, Sub-Antarctic fur-seal and southern elephant seal, on Sub-Antarctic islands;
* waters adjacent to breeding colonies on the Australian coast and waters adjacent to Sub-Antarctic islands; and
* favoured feeding places of seals.

Diet and breeding

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. Seals usually breed on land or on ice, with peak mating and pupping taking place in the summer months for most species. Seal pups become independent from their mothers at ages varying in Australian seals from 10 weeks to about a year and a half in Australian sea-lions.
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 colony in Bass Strait, were completely destroyed. Today, all seals are protected in Australia and populations are generally recovering from this over-harvesting.

However, seals may be affected by several human activities including:

* conflict with commercial fishing
* entanglement in fishing gear and other debris
* reduction in food supply
* human disturbance, including tourism, aircraft and vessels
* oil spills and chemical contaminants
* diseases

Seismic survey activity and climate change may potentially impact seals, although little is known about the effects of these at this time.
Legislative Protection

Australia's main piece of conservation legislation is the Environment Protection and Biodiversity Conservation Act 1999 (Australian Government) (the EPBC Act), which came into force on 16 July 2000.

Seals located in all Australian Commonwealth waters are protected under the EPBC Act, and seals located south of 60°S are protected under the Antarctic Treaty (Environment Protection) Act 1980 and associated conventions including the Seals Convention. In addition, seals in Commonwealth marine protected areas that surround the world heritage listed sub Antarctic islands of Macquarie Island, and Heard and Macdonald Islands are also protected under the EPBC Act. Read more information about seal protection under the Antarctic Treaty .

Under the EPBC Act all marine mammals occurring within Australian waters are listed 'Marine' (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/Territory waters or on State/Territory land, relevant State /Territory legislation applies.

Three species of seal are listed under the EPBC Act as 'Vulnerable' — the Subantarctic Fur-seal (Arctocephalus tropicalis), the Southern Elephant Seal (Mirounga leonina) and the Australian Sea-lion (Neophoca cinerea) (section 178). In accordance with the EPBC Act, a recovery plan for the Sub-antarctic fur seal and southern elephant seal was made by the Australian Government in 2004. Read the Sub-antarctic fur seal and southern elephant seal recovery plan and a supporting background document.

In addition to the levels of protection afforded to listed 'Marine' and 'Threatened' species, the EPBC Act also requires that any action that has, will have or is likely to have a significant impact on listed species in the threatened or migratory categories must be referred to the Department of the Environment, Water, Heritage and the Arts for assessment — this applies in States and Territories as well as Commonwealth land and waters. Any action that may have a significant impact on a Commonwealth marine area should also be referred for assessment under the EPBC Act. Criteria for considering whether an action impacts on the environment in a Commonwealth marine area includes whether populations of marine species will be substantially adversely affected.

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 or place themselves in any danger — seals can bite! 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.

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