The world's largest coral reef stretches more than 2,300 km along the northeast coast of Australia. It is home to some 1,500 species of fish and around 4,000 types of molluscs.
A new episode of mass bleaching of the Great Barrier Reef along Australia's northeast coast, the seventh since 1998, is underway. The dieback phenomenon, which results in discoloration, is caused by an increase of just one degree in water temperature which causes the expulsion of symbiotic algae.