India has several marine national parks and sanctuaries, which are protected by the law. In India, there are marine national parks like Gulf of Kutch (Gujarat), Gulf of Manner (Tamil Nadu) and several around Andaman Islands.
Similarly, there are marine sanctuaries in West Bengal and the Bhitarkanika and Nalavan sanctuaries in Chilika in Odisha. life can be found in the deepest and darkest corners of the ocean but most of the creatures are found in three main areas, which are known as most rich biological hub of marine ecological systems. (1) The surface water of the sea, where the sun light is very prominent. Millions of microscopic plants and animals are found in this region. (2) Region of bio-diversification is the shore and deep waters, where many types of free swimming fish are noticed. Commonly, all the oceanic mammals are noticed within these zones.
The Indian Ocean is very rich in bio-diversification. The entire globe has seven types of oceanic turtles but five types of such species are noticed in the India Ocean alone. Out of the five species, four species come to the sea shore for making nests, especially in sand beds. The Indian Ocean is known as Turtle Paradise. Four species like leather back turtle, the green turtle, the hawks bill turtle and Olive Ridley are available in this ocean.
The Olive Ridley turtles come to Odisha coast for nesting and breeding every year. The Olive Ridley feeds on fish, shrimp, crabs and snails. It is the commonest turtle along the Indian coasts. The species, although lives in different depths of water, it comes ashore to lay eggs on the sandy beaches. The marine turtles are now declared as endangered species. They are killed for meat, fat, shell and skin, including the eggs. The eggs are in great demand. The leather back turtle is the largest and rarest of sea turtles. It has a leathery covering instead of shell. The leather back is a deep-sea feeder. It lives mainly on Jellyfish. The Jellyfish are to be protected for survival of the leather back turtles. Due to habitat destruction caused by sea poisoning and mechanized fishing, the population of Jellyfish is drastically reduced. The leather back turtle is mainly noticed around the Andaman and Nicobar Islands. As the name suggests, the colour of green turtle is dirty green. The shell and the flesh of this turtle are green. It is generally noticed in shallow seas. It feeds mainly on marine algae and sea grass. large nesting site is found near Karachi, including Gulf of Manner and lakshadweep and Andaman and Nicobar Islands.
The head and beak of the hawk bill turtle is that of a bird. It lives mainly on coral reefs and nests on the shores of the Andaman and Nicobar Islands. The species is widely distributed in the ocean water.
The most flourishing bio-diversifications of plants and animals are noticed within the mangroves and that of habitat of coral reefs.
In Odisha coast, there are three marine sanctuaries, such as Bhitarakanika, Gahirmatha and Nalabana. These are very potentially rich sanctuaries of wet land ecology. The Bhitrakanika sanctuary is a national park. There are 381 estuarine villages within the sanctuary – cum national park region, where about two lakh people reside.
The minimum winter temperature is around 10 degree C and summer temperature goes up to 43 degree C. The common animal species are various cats like leopard, fishing cat, jungle cat etc. Other than cats, Hyena, Wild Boar, Spotted Deer, Sambar, Porcupine, Dolphins, Pythons, King Cobra, salt water crocodiles, white crocodiles, water monitor lizard, terrapins marine turtles etc are also found. Besides animals, the bird species like Kingfishers, Wood Peckers, Horn bills, Bar headed goose, Brahmani ducks, Pin tails, White belled sea eagles, and a variety of resident and migratory birds are found there. This is a paradise of nesting birds. There are other cultural trails and spots to enjoy the magnificent ecological systems. There is an ancient Shiva temple within the sanctuary, which exists since Darbar regime. Another feature of the sanctuary is its silted lotus pond. The lotus species is now almost going to be extinct from Odisha as the silted ponds are converted into urban and semi-urban land. The residual floristic land of Bhitarkanika brings immense pleasure in the minds of the visitors. Similarly, in the east shooting tower of Kanika Raja is another attraction. The shooting tower can be converted in to a watch tower-cum -holiday home for the tourists for enjoyment of the bio-sphere.
Another attraction of the sanctuary is meadows, which become the home of all classes of herbivores. Both carnivores and herbivores can be witnessed from the tower erected over the meadows.
The Gahirmatha sanctuary is a part of the Bhitarkanika geo-physiographic structure. This extends along the coast from Nasi Island in the north east to Telanga Muhan (Mahanadi mouth) in the south west. The sanctuary extends over 20 km into the sea. It has been created to protect the endangered Olive Ridley sea turtles, dolphins and other marine flora and fauna. Gahirmatha coast is used by lakhs of Olive Ridley sea-turtles for mass-nesting. Besides Olive Ridley, other animals like dolphins, jackals, hyena, fishing cat, crocodile, water monitor-lizard, tarns, vultures and winter migratory birds are found.
The Nalaban sanctuary is a part of the Chilika lagoon. Chilika as such spreads over vast wet land in the districts of Puri, Ganjam and Khurda. The famous Irrawaddy Dolphin and many species of migratory birds are found here. The lake is studded with small fascinating islands and sandy beaches interspersed with casuarinas groves along the Bay of Bengal. This estuarine sanctuary is famous for 95 species of migratory birds, besides varieties of reptiles such as snakes, lizards and aquatic mammals. During 1989-90 two million birds visited the lake. The Zoological Survey of India estimated in 1985-87 that there are 800 species of fauna within the lagoon wetland, which is a paradise of aquatic fauna and avifauna. This was declared as Ramasar site in 1981 under the conservation of wet lands of international importance as water fowl habitat. The limbless skink, a typical lizard of tropical Africa and Asia is also found in the Chilika islands.