Great Barrier Reef

Great Barrier Reef

The Great Barrier Reef is the only living organic collective visible from Earth's orbit. The Great Barrier Reef, off the east coast of Australia, is one of the wonders of the natural world - it is the world's largest coral reef ecosystem. It was declared a World Heritage area in 1981 and added to the National Heritage List in 2007. Great Barrier Reef

The reef is scattered with beautiful islands and idyllic coral cays and covers more than 300,000 square kilometres. The Great Barrier Reef system consists of more than 3000 reefs which range in size from 1 hectare to over 10,000 hectares in area. Dunk Island is one of more than 600 islands of the Great Barrier Reef. Great Barrier Reef

Human activity in the Reef areas has led to increased pollutants and the reef has suffered damage. Protecting the Reef is the responsibility of the Marine Park Authority. In 2003, the previous Australian Government and Queensland Governments, in partnership with a wide range of industry and community groups, developed the Reef Water Quality Protection Reef Plan (the Reef Plan) as a combined effort to protect the Reef. Great Barrier Reef

Of particular concern is wetlands - which have decreased by over 50 per cent since European settlement. The Great Barrier Reef Coastal Wetlands Protection Program is developing measures for the long term conservation and management of priority wetlands. Great Barrier Reef

The coral

Corals make up the various reefs and cays. These are the basis for the great variety of sea and animal life in the Reef. Coral consists of individual coral polyps – tiny live creatures which join together to form colonies. Each polyp lives inside a shell of aragonite, a type of calcium carbonate which is the hard shell we recognise as coral. The polyps join together to create forests of coloured coral in interesting fan, antler, brain and plate shapes. Great Barrier Reef

The ideal environment for coral is shallow warm water where there is a lot of water movement, plenty of light, where the water is salty and low in nutrients. There are many different types of coral, some are slow growing and live to be hundreds of years old, others are faster growing. The colours of coral are created by algae. Only live coral is coloured. Dead coral is white. Great Barrier Reef

One of the greatest dangers to the habitat is the Crown of Thorns starfish. Since the 1960s the Crown of Thorns has been destroying the corals which make up the reef. Crown of Thorns outbreaks go through a series of stages which can take from 1 to 15 years. The impact of a Crown of Thorns infestation on sea and bird life can be significant as the corals die. Great Barrier Reef

Another scourge of the reef is bleaching, where corals have died in large numbers. This phenomenon is not exclusive to Queensland's Great Barrier Reef, but has been observed on reefs throughout the world. It is thought the bleaching has been caused by rises in water temperature related to the El Nino effect, although the evidence is not conclusive. Great Barrier Reef

The coral has, over the years, brought many ships to grief including Captain James Cook's ship Endeavour. One of the most famous wrecks is that of the HMS Pandora, which foundered in 1791. The Queensland Museum has been leading archaeological digs to the Pandora since 1983 and its most recent was completed in February 1999. There are 30 shipwreck sites known in the marine park. Great Barrier Reef

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