The Lakshadweep Archipelago forms a terrestrial ecoregion together with the Maldives and the Chagos. It has over 600 species of marine fishes, 78 species of corals, 82 species of seaweed, 52 species of crabs, 2 species of lobsters, 48 species of gastropods, 12 species of bivalves, 101 species of birds. It is one of the four coral reef regions in India. The corals are a major attraction for the tourist. Pitti Island, is an important breeding place for sea turtles and for a number of pelagic birds such as the brown noddy lesser crested tern and greater crested tern . The island has been declared a bird sanctuary.