ome 2,000km. long the Australian Great Barrier Reef is the world's largest coral-reef formation.
The reef comprises some 2,800 fringing reefs, ribbon reefs and platform reefs.
Global warming has seen the water temperature rise more than 1 degree Celsius in the last 50 years and causing bleaching of the coral.
At the current rate of bleaching the whole reef could be dead in less than 30 years. This is causing great concern to environmentalists and the tourism industry.
Sydney University has a Coral Reef Research Institute looking closely at the situation.
The Reef attracted more than 2 million visitors in 1998 and generates up to $2 billion revenue per annum, nearly 10% of the national tourism revenue total.