Coral reefs are among the most productive and diverse ecosystems on Earth (Connell, 1978), They are critically important in supporting a vast biological diversity and genetic library for future generations (Moberg & Folke 1999). They provide goods, services and livelihoods for a vast number of people: seafood products, raw materials for medicines, jewellery and curio trade, live fish and coral for aquarium, recreational activities, building materials and (critically) coastal protection against wave action (Kuhlmann 1988, Gomez et al. 1994, Done et al. 1996, Moberg & Folke 1999). Furthermore they provide biotic services such as spawning, breeding, nursery, and feeding grounds for a wide range of organisms (Moberg & Folke 1999). They also fulfil biogeochemical functions such as nitrogen fixation in nutrient poor environments, act as sinks for carbon dioxide over geological time scales and are also found to have a significant role in the world’s calcium balance (Kuhlmann 1988, Hallock 1997).