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Environmental management > Coast and oceans > Great Barrier Reef

About the Reef

The Great Barrier Reef covers some 20 000sq.km of reef surface, possibly the biggest structure ever made by life on this earth! The area is bigger than Victoria or Great Britain and half the size of Texas.

The Reef is made by billions of living organisms that secrete limestone. These are principally corals, which can extract dissolved limestone from the water and lay it down as hard limestone cups around the lower half of their bodies. If necessary, coral polyps can pull their whole bodies inside these limestone cups for protection.

The combined limestone cups of many colonies of coral polyps form larger corals of many different shapes, sizes and colours. Around 400 different types of hard and soft corals exist. Algae and sponges grow between coral communities and help cement them into solid reefs.

Animals in the Great Barrier Reef region include thousands of species of molluscs (clams, snails and their relatives); thousands of different sponges, worms and crustaceans (crabs, shrimps and their relatives); echinoderms (starfish, sea urchins, sea cucumbers and their relatives); and many other less familiar creatures.

More than 1500 species of fish live on the Reef, which also provides breeding areas for humpback whales, sea turtles and dugong.

The Reef is an important feeding and breeding area for seabirds.

Plants on the reef are vital to the reef system. Hundreds of species of algae, including seaweeds, live on the reef, but many are inconspicuous.

More than 1600 known shipwrecks are in the Great Barrier Reef region. Access to some sites requires a permit from Queensland Museum.

Throughout the Reef are hundreds of continental islands, reef islands and cays, small bare sand cays, and permanent vegetated cays.

In recognition of its universal value, the Great Barrier Reef was inscribed on the World Heritage list on October 1981.

Last updated: 24 March 2006