Crowning corals

Abstract

Biodiversity of coral reefs is responsible for productivity in the sea and these coral reefs are built mainly by corals containing a calcium-carbonate skeleton. The reef building corals are the hermotypic corals harbouring zooxanthellae and the chermotypic corals, without zooxanthellae. Coral reefs are found in waters upto a depth of 50-70 m, well lighted zones having salinity of 32-35% and temperatures of above 20 degrees C. Coral reefs are abound in a variety of fascinating animal life such as giant clams, sea cucumbers, sea anemones, sea urchins, sea fans, crown-of-thorns starfish and a variety of coloured fishes. Each of these animals have a special niche in this system. The three major types of reefs are the fringing reefs, barrier reefs and the atolls. Reefs all over the world are dwindling fast. The major agents of destruction of coral reefs are abiotic and biotic factors such as hurricanes, bioerosion, sedimentation, eutrophication, pollution, predation and diseases. Pollution by oil spill and oil transport, thermal pollution and freshwater inflow are the major threats to corals growing along the urban and industrialised centres. Therefore, a concerted effort from academicians, governmental and non-governmental bodies to educate the public and build-awareness about the rich, diverse biological resources is warranted and a plea is made to manage the sewage, oil and thermal pollution to help preserve the biodiversity of coral and associated flora and fauna.