Coral reefs are one of the most biologically diverse marine ecosystems on the Earth. Corals grow over geological time scales and have been in existence for about 200 million years. • Coral reefs play an important role in marine ecosystem and support the habitats of flora and fauna in the sea. • Australian Great Barrier Reef, Belize Barrier Reef and the New Caledonian Barrier Reef, The Mesoamerican Barrier Reef System, The Florida Reef Tract and Rainbow Reef are some examples of coral reef. • Kyushu Island (Japan) is not a coral reef island. • In India, Coral reefs are present in the areas of Gulf of Kutch, Gulf of Mannar, Andaman & Nicobar, Lakshadweep Islands and Malvan.