Ashmore and Cartier Islands

The Territory of Ashmore and Cartier Islands comprises West, Middle and East Islands of the Ashmore Reef, Cartier Island and the 12 nautical mile territorial sea generated by these islands. The islands are uninhabited and composed of coral and sand with some grass cover.

The Territory is located on the outer edge of the continental shelf in the Indian Ocean, approximately 320 km off Australia's north-west coast and 144 kilometres south of the Indonesian Island of Roti. The Jabiru and Challis oil fields are adjacent to the Territory.

In early May 1996 Indonesian and Australian officials at the request of the Indonesians visited the Territory with the objective of satisfying Indonesian officials that the Territory does in fact include islands generating a 24 nautical mile boundary. This has important implications for negotiations between Australia and Indonesia on the maritime boundary.

Governance and Administration

The Territory was accepted from Britain in 1933 and responsibility for the administration was transferred from the Northern Territory to the Commonwealth when self-government was instituted in the Northern Territory in 1978.

Petroleum extraction activities in the area adjacent to the Territory are administered on behalf of the Commonwealth by the Northern Territory Department of Mines and Energy.

Commonwealth laws, laws of the Northern Territory and Ordinances made by the Governor-General make up the body of law applicable in the Territory of Ashmore and Cartier Islands.

Environment and Heritage

In 1983 the Ashmore Reef National Nature Reserve (583 sq km) was established under the National Parks and Wildlife Conservation Act 1975. Cartier Island Marine Reserve was established in 2000.

Access to East and Middle Islands, the main sea bird breeding areas, is by permit only. Under a Memorandum of Understanding signed by Australia and Indonesia in 1974 traditional Indonesian fishermen are allowed access to the lagoon and the fresh water supply of West Island.

Illegal killing of protected wildlife by traditional Indonesian fishermen and fishing by non-traditional Indonesian vessels are ongoing problems in the Territory and the surrounding waters.

The Royal Australian Navy and the Australian Customs and Border Protection Service undertake patrols of the reserves and associated islands and reef ecosystems to ensure their protection against illegal foreign fishing. When illegal activity is suspected crews are arrested, prosecuted and their vessels impounded.

Following an increase in illegal fishing activity the Department of Foreign Affairs and Trade and the Australian Fisheries Management Authority conducted educational visits to Indonesia to discourage non-traditional visits.


Indonesian fisherman have traditionally utilised the coastal resources of the Territory since the early eighteenth century. Prevailing trade winds and local land marks were used to set course and sail between the islands.

The first recorded European discovery of the islands was on the 11 June 1811. Captain Samuel Ashmore, commander of the Hibernia was titled with the discovery of Ashmore Island, and Captain Nash was credited with the discovery of Cartier Island and the nearby Hibernia Reef.

The 1850s saw the operation of American whalers in the region, and upon the discovery of phosphate deposits in the latter half of the nineteenth century mining began on Ashmore Island.

In the late nineteenth century Britain and the United States of America contested the ownership of Ashmore Island, with Britain assuming ‘formal’ possession in 1878. British sovereignty over the Island was later declared, with the subsequent annexation of Cartier Island taking place in 1909. The official proclamation of British land occurred on 17 May 1909.

On the 23 July 1931 an order-in-council placed Ashmore and Cartier Islands under the authority of the Commonwealth. It was not until 10 May 1934 that the Ashmore and Cartier Island's Acceptance Bill was brought into operation and Australia officially acquired a new external territory.

During the Second World War the territory received various naval visits and was used as a bombing and air weapons range for defence purposes. Throughout the 50s and 60s unmanned navigational lights and meteorological stations and signs were constructed, with naval visits and aircraft surveillance continuing.

In 1974 Australia and Indonesia entered into a Memorandum of Understanding (MOU) recognising the traditional use by Indonesian fisherman of the territory's resources, and granting the rights of access to Australian waters. Under the MOU traditional Indonesian fisherman are permitted to land on West Island to replenish their stores of fresh water, visit the graves of past fishers and to take shelter in the West Island Lagoon.

In 1983 the Territory was declared a nature reserve under the National Parks and Wildlife Conservation Act 1975.

In September 2001, Ashmore and Cartier Islands were excised from the Australian Migration Zone.