Community Structure and Spatial Patterns in Hard Coral Biodiversity in Selected Islands in the Gulf of Mannar, India

Abstract

The major reefs of the Gulf of Mannar Biosphere Reserve extend from the Tuticorin group of islands (Long.7809’E, Lat.8048’N) to the Shingle Island (Long. 79014’E, Lat.9014’N) in Mandapam, India. These reefs are under increasing threats from anthropogenic interventions. In view of this, a comparative study was conducted to deduce the spatial patterns in the hard coral biodiversity and community structure of five islands of the Mandapam group. The islands studied are Shingle, Krusadai, Pullivasal, Manauli and Hare. Univariate community parameters, Shannon–Wiener diversity index (H’e), Simpson diversity index, and Pielou’s evenness index were calculated for each reef in each sampling station. The highest and lowest percentage of live coral cover was recorded in the reefs of the Shingle (60.8%) and Pullivasal Islands (13.9%) respectively. Shannon index of diversity recorded maximum value in the reefs of Manauli Island (3.01) and the minimum in Pullivasal Island (1.8).