Abstract
The beautiful forests of Sunder bans embracing mysterious tracts of wilderness are located in the lower Ganga delta of Bengal. The mangrove forests and the overall ecosystem in Sunder bans are the ideal habitats for large group of terrestrial, avian and aquatic fauna, starting from Protozoa to Mammals. It contains the richest biodiversity among the inter-tidal forest in the worlds and is the only natural mangrove forest in the world, where the tiger (Panthera tigris tigris L.) resides. The reason for high faunal diversity is the fact that here the ocean and land comes in contact of each other. The succession from ocean to land and to fresh water/ brackish-water through estuaries, change in water salinity from almost nil to high through grades of different concentration; newly formed islands with soft swampy mud to mature old islands with hard saline banks provides fascinating habitat opportunities to various organism. During the last two centuries, these highly productive mangrove ecosystems had been suffering from rapid degradation. If this negligence or ignorance continues in future there will be random exploitation of this natural resource and loss of diverse biota will be unavoidable. A genuine understanding of the interaction of responsible factors should be of paramount interest to the estuarine ecosystem and for prosperity. Recently, it has been established that natural factors along with direct and indirect human interferences have largely changed the biological composition, ecosystem function, productivity, and regeneration and succession patterns within the mangrove ecosystem.
