Sundarbans mangrove deltaic system – An overview of its biodiversity with special reference to fish diversity

World heritage site-Sundarbans were declared as the world’s 560th Ramsar Wetlands site in 1992. Sundarbans ecosystem supports rich fisheries diversity and also natural biodiversity hot spot, because it is natural habitat of many endangered species. The Sundarbans is a home to a variety of faunal species, the total of 1586 species has been recorded which includes 481 Vertebrate species (30%), 1104 Invertebrate species (70%). Mangroves are the nursery and breeding grounds for several commercially important species of aquatic fauna like fish, shrimps and prawns etc. Mangrove ecosystems are of great ecological significance in the tropical and sub-tropical coast. Sundarbans mangrove provides a variety of ecosystem services. However, the Sundarban mangrove forest is the most threatened habitats in the world, increased population with few alternative livelihood opportunities poses a serious threat as it is the main cause of mangrove destruction. The total value of Sundarbans is not recognized and therefore often neglected in development planning. As a result Sundarbans conservation issue is getting less importance at the national level. The study reveals that major ecosystem services of Sundarbans are timber, fuel wood, fish, ecotourism, cyclone and storm protection, biodiversity, and habitat for flora and fauna. Timber, fuel wood and fish are more economical provisioning services in Sundarbans. It is noticed that there is decreasing tendency of overall revenue collection from the mangrove over the period of 2001-02 to 2009-10. The attention from national and international communities is needed for sustainable management and conservation of the Sundarbans. The study suggests that further research on total economic value of Sundarbans is needed for providing comprehensive scientific information for policy as well as for decision makers