Ashmore and Cartier Islands

The Territory of Ashmore and Cartier Islands is an uninhabited external territory of Australia comprising four low-lying tropical islands and their surrounding territorial seas in the eastern Indian Ocean. Situated on the edge of the continental shelf, the islands lie off north-western Australia and south of the Indonesian island of Rote. Despite their small size, the islands hold ecological, historical, strategic, and cultural importance and remain protected as nature reserves under Australian law.

Geographic Setting

The territory consists of two separate reef systems:

• Ashmore Reef, containing West, Middle, and East Island, as well as two lagoons.
• Cartier Reef, containing Cartier Island.

Ashmore Reef spans several square kilometres, while Cartier Reef is smaller but still ecologically significant. The combined land area of West, Middle, and East Island is only a few hectares, with Cartier Island also extremely small. These islands rise only slightly above sea level and are surrounded by expansive reef flats and shallow waters. Nearby Hibernia Reef, although close in proximity, forms part of Western Australia rather than the territory.
Ashmore Reef carries Indonesian names such as Pulau Pasir and Nusa Solokaek, both meaning “sand island,” reflecting long-standing regional cultural links.

Historical Overview

European contact began in the early nineteenth century. Cartier Island was visited in 1800 by Captain Nash, who named it after his ship Cartier, while Ashmore Island was sighted by Captain Samuel Ashmore in 1811. The United Kingdom annexed Ashmore Island in 1878 and Cartier Island in 1909. Licences for fishing and guano extraction were periodically issued during the late nineteenth and early twentieth centuries.
By the 1920s the islands had become bases for illicit pearling activities, prompting Australia to lobby for administrative control. A British order-in-council of 1931 authorised the transfer of authority to the Commonwealth of Australia, effected by the Ashmore and Cartier Islands Acceptance Act 1933. Administration formally commenced in 1934. In 1938 the islands were annexed to the Northern Territory for administrative purposes, although responsibility reverted to the Commonwealth following the granting of Northern Territory self-government in 1978.
During the mid-twentieth century, visits by Australian officials were rare. The territory acquired protected status in 1983 under the National Parks and Wildlife Conservation Act, later replaced by the Environment Protection and Biodiversity Conservation Act 1999. Cartier Island, used historically as a bombing range, became a marine reserve in 2000.
In September 2001 the islands were excised from the Australian migration zone, reflecting their prominence as entry points for asylum seekers travelling from Indonesia during that period.

Indonesian Heritage and Traditional Access

Indonesian fishers have visited Ashmore Reef for centuries, long before European contact. A 1974 Memorandum of Understanding between Australia and Indonesia preserves traditional rights for certain Indonesian communities. Under this agreement, traditional fishers may enter designated areas—known collectively as the MOU Box—to seek shelter, obtain freshwater, and visit grave sites. These arrangements recognise historic maritime patterns and cultural ties to the reef.

Governance and Administration

The islands have no permanent population and are administered from Canberra by the Department of Infrastructure, Transport, Regional Development, Communications and the Arts. This department also oversees other external territories such as Christmas Island, the Cocos (Keeling) Islands, the Coral Sea Islands, Norfolk Island, and the Jervis Bay Territory. Defence responsibilities fall to the Royal Australian Navy, the Royal Australian Air Force, and the Australian Border Force, which conducts regular patrols.
Seasonal caretakers and scientific researchers occasionally visit the reef systems. Access to Cartier Island is prohibited due to the presence of unexploded ordnance. Water sources on the islands are not potable, reflecting environmental degradation and contamination of natural wells.

Proposed Northern Territory Annexation

The Northern Territory government has periodically advocated for the incorporation of the islands into its jurisdiction. Reports in 1989 and 1996 supported this position, and a 1991 parliamentary committee recommended annexation. In the lead-up to the 1998 Northern Territory statehood referendum, the Australian Government indicated its intention to pursue annexation. Nevertheless, no change in legal status occurred, and the territory remains separate from the Northern Territory.

Environment and Protection

Both the Ashmore Reef Marine Park and Cartier Island Marine Park are designated as strict nature reserves (IUCN Category Ia), protecting significant biodiversity and fragile marine ecosystems. The reefs support diverse coral communities, migratory seabirds, marine turtles, and important fish species. Their isolation enhances ecological value, and their management focuses on conservation and controlled access.
Ashmore Reef is monitored extensively, with an Australian Border Force vessel stationed in the vicinity for substantial portions of the year. These efforts help protect the area from illegal fishing and support the enforcement of environmental regulations.

Economy and Resource Use

Although uninhabited, the reefs have long served as traditional fishing grounds for Indonesian communities, particularly for trepang (beche-de-mer), trochus shell, and other marine resources. In the nineteenth century guano extraction and limited phosphate mining took place. The surrounding waters were also visited by American whalers in the 1850s.
Modern commercial activity does not occur within the territory itself, but nearby petroleum fields—such as Jabiru and Challis—are administered by the Northern Territory on behalf of the Commonwealth, illustrating the wider economic significance of the region.

Migration and Strategic Importance

Ashmore Reef’s proximity to Indonesia made it a frequent destination for asylum seeker vessels in the late 1990s and early 2000s. Landing on the islands previously conferred entry into the Australian migration zone, enabling claims for refugee processing. The Australian Government sought to discourage such arrivals by implementing measures including interdiction at sea, offshore processing arrangements, and legislative excision of the islands from the migration zone.