why is great barrier reef on the world heritage list
The Great Barrier Reef is the world's largest reef system, composed of roughly 3,000 individual reefs and 900 islands that stretch for 2,600 kilometres (1,616 mi) and cover an area of approximately 344,400 square kilometres (133,000 sq mi).he Great Barrier Reef is the world's largest reef system, composed of roughly 3,000 individual reefs and 900 islands that stretch for 2,600 kilometres (1,616 mi) and cover an area of approximately 344,400 square kilometres (133,000 sq mi).