Longest reef

The Great Barrier Reef off Queensland, north-eastern Australia is 2027km 1260miles in length. It is not actually a single reef but consists of thousands of separate reefs. On three occasions, between 1962 and 1971, 1979 and 1991 and between 1995 and the present, corals on large areas of the central section of the reef have been devastated by the crown-of-thorns starfish (Acanthaster planci).