India has a total coastline of 7,516.6 r which opens into the Indian Ocean, Arabian Sea and the Bay of Bengal. Besides, Andaman-Niobrara Lakshadweep group of islands have complete marine environment. The ecology of these areas is threatened by growing economic activities like shipping, exploration and extraction of mineral oil, fishing, prawn culture, farming and disposal of industrial and city wastes.
The sea has been highly polluted up to an extent of 5 km from the coast near Mumbai. Many beaches have lost their charms due to growing pollution. The extraction of mineral oil from the coast of Gujarat and Bombay High is creating adverse effect on the marine life of the area; the prawn culture is threatening the environment along the eastern coast. So much so that the survival of the Chilka lake is at stake. Along the Tamil Nadu and Andhra coast organised prawn farms are adversely affecting the rice farming and fishing activities in the areas.
Coral bleaching is increasing along the Lakshadweep and Andaman coasts. Famous Blair Reef near Port Blair and adjacent to the Chatham; Island is dying due to the dumping of massive I quantities of saw dust into the sea. Leaks from the ship and the shore pipeline of petroleum products near Chatham worsen the problem. In many parts of the islands and coastal areas reefs are being destroyed for their use as raw material in cement industry and road building. The INTACH study on
the ‘Human-derived damage to coral reefs in Andaman’s’ attributes the biggest damage to coral reefs in Andaman’s to turbidity in the shallow coastal regions (that harbour the reefs) caused by silt brought down by soil erosion due to deforestation and construction activities, particularly road laying (Acharya, S. 1993, p.68). Similarly deforestation, agriculture, road laying and subsequent soil erosion bring large quantities of nutrients into the coastal waters, resulting in aphid-plankton bloom and increasing population of starfish which poses severe threat to coral reefs.
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Dugongs (a species of marine mammals), once very common in the Little Andaman’s, are extremely rare today and perhaps endangered species. The INTACH-SANE study attributed the fall in their number to forest clearance and road laying in Little Andaman’s. Massive collection of corals, sea cucumbers and ornamental fishes is going on for their high demand in international market. A considerable number of foreign poachers are also operating within our EEZ and are causing immense damage to our marine life and environment. Even growing tourist activities are causing harm to marine life, especially corals. Tourists could kill the corals merely by standing on it.
The loss of coral barriers has exposed coastal areas to sea erosion. Coastal mangroves constitute extraordinarily rich ecosystems which contain many unique species adapted to the unusual habitat and are also key nursery areas for many species of fish and crustaceans. These mangroves, which form a vital protection against cyclone damage and tsunamis, have already been lost from most of our coastal areas. They only exist in the Sundarbans (West Bengal), Bhitarkanika Sanctuary (Orissa), Coringa Sanctuary (Andhra Pradesh) and in the Andaman and Nicobar Islands.