Diversity and distribution of corals and their associated fauna of Rani Jhansi Marine National Park, Andaman and Nicobar Islands

Abstract

Coral reefs of Andaman and Nicobar Islands are considered as one of the highly productive reef ecosystem in Indo-Pacific region. Rani Jhansi Marine National Park (RJMNP) of Andaman is one among four marine national parks in India, composed of three islands, viz. Outram, Henry Lawrence and John Lawrence Islands of Ritchie's Archipelago with a total coral reef area of 27.15 km2. In order to assess the current diversity of scleractinian coral and its associated fauna in RJMNP, periodic surveys were conducted between the year 2009 and 2011. As a result, a total of 148 species of scleractinian corals belonging to 11 families were reported from RJMNP, of which 37 species belongs to the family Acroporidae. The percentage of live coral cover ranged from 59.53% in Henry Lawrence Island to 63.71% in John Lawrence Island. Besides, 27 species of octocorals, 17 species of sponges, 30 species of echinoderms, 100 species of molluscs, 54 species of nudibranchs, 52 species of crabs and 216 species of fishes were recorded as coral-associated fauna. The density, diversity and distribution of all these faunal groups were calculated along with the physico-chemical characteristics of seawater, and the findings are discussed in detail.