The Law of the Sea

Australia is a vast continent with a distinctive outline. The 'real' Australia is very different and extends offshore well beyond the current coastline. Throughout Earth's history the processes of climate change, erosion and plate tectonics have altered the amount of land that is above sea level. The area under Australian jurisdiction has also changed, but on a much faster timescale - during human history.

What is 'Law of the Sea'?

The Law of the Sea is a body of international rules and principles developed to regulate ocean space, as reflected in the 1982 United Nations Convention on the Law of the Sea (UNCLOS). Australia participated in all three United Nations conferences on the Law of the Sea (1958, 1960 and 1973-82) and became party to UNCLOS in 1994.

An international agreement about the sea became necessary when many nations realised the wealth of resources there - especially fisheries and mineral resources. These marine resources are not endless and need to be managed in an effective and sustainable manner.

All of the countries bound by UNCLOS must follow rules about marine boundaries, access to the various marine zones and managing the resources and activities within those boundaries. All member countries of the United Nations are eligible to become a party to UNCLOS, whether or not they have a coast. During the drafting of UNCLOS, the needs of land-locked and geographically disadvantage countries were taken into account.

How much territory does Australia have?

The Australian continent is very large, covering about 7.7 million square kilometres.

The territories of Australia include the Australian Antarctic Territory, Christmas Island, the Cocos (Keeling) Islands, Heard and McDonald Islands, Norfolk Island, the Coral Sea Islands and Ashmore and Cartier Islands. In total there are some 12 000 islands. While many of these islands are relatively small, UNCLOS allows Australia jurisdiction over tracts of the ocean and seafloor that surround them.

Australia has an Exclusive Economic Zone (EEZ) that extends beyond the 12 nautical mile territorial sea to a distance of 200 nautical miles (one nautical mile is internationally defined as 1.852 kilometres) in most places. This zone is measured from the territorial sea baseline (see Maritime Boundary Definitions). The EEZ gives jurisdiction over a marine area of some 10 million square kilometres. In some places, Australia's continental margin extends further out than the 200 nautical mile limit.

In such places, under Article 76 of UNCLOS Australia has the right to make a submission to the Commission on the Limits of the Continental Shelf (CLCS) to delineate the outer limits of these areas of "extended" continental shelf. This is largely a scientific task and defines the limits of Australia's jurisdiction over the seabed and subsoil beyond 200 nautical miles - in fact, marine areas equivalent to about 35% of the Australian continental landmass have now been added - an area equivalent to the size of Western Australia.

Australia's submission for areas of extended continental shelf was lodged with the CLCS on 15 November 2004. Since then, an Australian delegation has made numerous presentations to the Commission and on 9 April 2008 the Commission adopted recommendations that confirmed the location of the outer limit of Australia's continental shelf in nine distinct marine regions. This decision gives Australia jurisdiction over an additional 2.5 million square kilometres of continental shelf that extends beyond 200 nautical miles from its territorial sea baseline.

More information on Australia's submission is given in the Executive Summary on the CLCS website.

Did you know

The mainland of Australia has only held its current shape for the last 6 000 years or so. Before that, the world was in its most recent Ice Age, which locked away water in the form of continental ice. There was so much of this ice that the global sea level was lowered, exposing areas of land that were underwater previously. For Australia, levels were low enough to join Tasmania with the mainland.