What is the Arafura Sea?

The Arafura Sea lies between northern Australia and the islands of eastern Indonesia and southern Papua. It is part of the western Pacific Ocean, covers about 650,000 square kilometres, and is shallow throughout, with average depths of just 50 to 80 metres because it sits on the Australia-Papua continental shelf.

The sea borders Australia's Northern Territory coast, including Arnhem Land, the Tiwi Islands, and the Cobourg Peninsula. To the east it opens onto the Torres Strait separating Cape York Peninsula from Papua New Guinea, where Australia and Papua New Guinea share a maritime border just five kilometres wide at its narrowest point near Saibai Island. To the west the Arafura merges with the Timor Sea, and to the north with the Banda and Ceram seas of Indonesia.

The Arafura is named after the Aru Islands of eastern Indonesia, which European traders historically visited for pearl shell, trepang (sea cucumber), and bird-of-paradise feathers. Macassan trepangers from Sulawesi sailed to the Arnhem Land coast for centuries before British settlement, trading and working with the Yolngu people, leaving lasting cultural exchanges in language, song, and material culture that pre-date European contact.

Today the Arafura Sea is a significant zone for Australian Border Force and the Royal Australian Navy, who patrol it for illegal fishing, drug trafficking, and irregular maritime arrivals. The Joint Petroleum Development Area in the Timor Sea adjacent to the Arafura was a major source of natural gas exports until production at the Bayu-Undan field ended in 2023, and the area remains central to negotiations between Australia and Timor-Leste.