GIDB - Gujarat Infrastructure Development Board

Corals

Coral reefs in India are found in six major areas viz. Andaman islands, Nicobar islands, Gulf of Mannar, Palk Bay, Lakshadweep and Gulf of Kachchh. Also, a maximum number of species (76 different species) of corals are found in the Gulf of Kachchh. Coral reefs are exclusive and unique marine ecosystems, diverse in nature, and growing continuously in size to form extensive masses. They build a framework of calcium carbonate (known as reef) which provides refuge to many other life forms. Given their sensitive nature, Coral reefs require specific ecological requirement such as temperature, salinity, light, water movement, depth, etc. for their survival and growth.

Coral reefs can be classified into three geomorphologic categories

Fringing reef: These type of reefs grow on or near shores along the margins and edges of continents. Sometimes they may also be separated from the shore by a shallow lagoon. Such reefs are most commonly found in Gulf of Kachchh and coast of Rameshwaram in Gulf of Mannar.
Barrier reef: These type of reefs develop on the edge of continental shelves or submerged islands that are separated from the mainland or island by a wide deep lagoon. Such reefs are most commonly found in Andaman & Nicobar islands, Lakshadweep islands and mini barrier reefs in Gulf of Kachchh.
Atoll reef: These type of reefs are found in a circular or horse-shoe shape wherein a deep lake is present in the centre surrounded by open sea. Such reefs are also referred as “Coral island” or “Lagoon island”. Such reefs are most commonly found in Lakshadweep islands and Maldives.

Worldwide coral reefs are confined to Atlantic, Indian and Pacific ocean, Indo-Pacific ocean.