The Sundarbans (21° 32ʹ and 22° 40ʹ N; 88° 05ʹ and 89° E) forms the largest contiguous stretch of mangrove ecosystem in the world. This mangrove ecosystem encompasses over 102 islands with a network of innumerable rivers, rivulets, and creeks and covers a total area of approximately 10,000 km2. This region is heavily influenced by South-Eastern monsoon which brings down huge amount of freshwater due to both local and regional precipitation.
The above map indicates the stretch of the Indian Sundarbans. Starting from Sagar Island in the west upto River Raimangal in the east, the Indian Sundarbans demonstrates a wide variety of niche type. The Sagar Island is the largest island in Indian Sundarbans. Once devour of its mangrove cover owing to extensive deforestation, it now has a mangrove cover consisting of entirely replanted mangroves. However, continous dredging activities along with anthropogenic pressure causes immense stress to these mangrove plants.
Moving eastward, one can see the core area of the Sundarbans Biosphere Reserve (SBR) which aims to protect the only salt marsh tiger, the Royal Bengal Tiger, and its habitat. The buffer zone allows limited human activities whereas the Sajnekhali Wildlife Sanctuary (WLS) is open to observation by humans.
The Indian Sundarbans have seven major estuaries that open into the Bay of Bengal. Mooriganga estuary receives a huge amount of freshwater from the R. Mooriganga. Moving more eastward, most rivers have lost their upstream connection to the Ganga owing to heavy siltation.
Stations of SBOTS is located in the Sundarbans mangrove ecoregion which lies in the Ganga-Brahmaputra-Meghna (GBM) delta and is shared between Indian and Bangladesh.