Ashmore and Cartier Islands

The Territory of Ashmore and Cartier Islands is an uninhabited external territory of Australia consisting of four low-lying islands in two separate reefs (Ashmore and Cartier), as well as the 12-nautical-mile (22 km; 14 mi) territorial sea generated by the islands. The territory is located in the Timor Sea on the edge of the Sahul Shelf, about 320 km (200 mi) off the northwest coast of Australia and 170 km (110 mi) south of the Indonesian island of Rote.

The Ashmore and Cartier Islands were discovered by Indonesian fishermen in the early 1700s and were regularly visited for the harvesting of sea cucumbers. Cartier Reef and Ashmore Reef were discovered by Europeans in around 1800 and 1811 respectively, and were mined for guano by American whalers in the late nineteenth century. Britain annexed Ashmore Reef in 1878 and extended its claim to include Cartier Reef in 1909, before transferring the territory to Australia in 1934. The islands were later visited by naval ships and were used as a weapons testing range. In 1983 the Ashmore Reef National Nature Reserve was established, and in 2000 this was followed by the Cartier Island Marine Reserve.

Under a 1974 memorandum of understanding, traditional Indonesian fishermen are permitted to access part of the Ashmore Islands and to fish in the surrounding waters. Australian authorities have regularly patrolled the reefs to combat illegal fishing and activities that fall outside of the scope of the agreement. Due to its proximity to Indonesia, the territory has also seen regular arrivals of asylum seekers seeking to claim refugee status in Australia. In 2001 the territory was excised from the Australian migration zone to prevent those arriving in the territory from claiming protection in Australia.

The territory is home to Ashmore Reef Marine Park and Cartier Island Marine Park. Each year about 100,000 seabirds breed on the Ashmore Islands, which is classified as an Important Bird Area. The reefs are also an important habitat for fish, sea cucumbers, turtles, and other species. Illegal fishing and introduced species, including fire ants and weeds, have been identified as threats to the islands' biodiversity.