The Sunderban is considered to be the largest single mangrove belt of the world comprising a total area of 9827 sq km, which lies in both India and Bangladesh, while the Indian part alone constitutes 4264 sq.km. The marshy deltaic bulge of the river Ganga is referred to as Sunderbans. It lies between 21o 0'- 21o21'N Lat. and 88o 0' - 89 o 0' E Long. The Sunderbans extends from the river Raimangal in the East to Hoogly in the West, North 24 Parganas in the North and Bay of Bengal in the South. Part of the Sunderban was declared as a Reserve Forest in 1978 and subsequently declared as Tiger Reserve. The total area of the Reserve Forest is 2585 sq km which includes 1600 sq km of land and the remaining 985 sq km as water body. Within the land area, 1330.12 sq km is designated as core area and the same was declared as a National Park in 1984. A primitive zone of 124.4 sq km is preserved within the core area, which acts as a gene pool. Hence Sundarban as a whole was declared as a World Heritage Site in 1985.
The Sunderban Regional Centre was established in the year 1979 at Kakdwip, West Bengal under the Fifth Five Year Plan of the Government of India, which is one among the sixteen Regional Centres of Zoological Survey of India. Subsequently it was shifted to Canning, West Bengal, in 1984. The jurisdictional limit of the Centre encompasses the entire Indian part of Sunderban. The major mandate of the Centre is to explore the rich faunal diversity in different ecosystems of Sunderban.