Indian Coral Reefs: Functions, threats and Management Issues

Coral reefs are formations of biogenous remains of carbonate secreting reef organisms and plants- in warm tropical seas. The principal reef builders being the scleractinian corals which exist in symbiosis with microscopic unicellular algae known as “Zooxanthellae”, the reefs constitute in themselves the most productive and diverse biological communities on earth. It has been estimated that 4 – 5% of all species described on earth occur on tropical coral reefs (Reaka-Kudla, 1995). These structures were reported to have first formed along the original continent of Pangaea 300 million years ago, even before the continents themselves began to drift apart and move to their present configurations (Veron, 1986). Recent molecular evidence suggests that living scleractinian corals may have evolved from two clades of soft bodied ancestors which are thought to have diverged 240 million years ago before they evolved hard skeletons (Romano and Palumbi, 1996). Most of the major coral reefs observed today are living veneers that have covered previously existing substrates only within the last 10,000 years (Maragos et al, 1996). Worldwide, coral reefs are found in over 100 countries and cover an estimated 2,84,300 square kilometers (ICRIN, 2002). Southeast Asia is the center of biodiversity for the reefs of the world and contains about one-third of the world’s coral reefs. In India, the total projected reef area is about 2,374.9 km2 (Baghuguna and Nayak, 1998) which fall under 4 major reef regions namely Andaman & Nicobar, Gulf of Kachchh, Gulf of Mannar and Lakshadweep Islands, and several intertidal patches along the west coast of India— reported at Vizhinjam, Kochi to Enayam, Mormugao, Malvan, Redi, Ratnagiri and Mumbai