Kolkata, Sep 24 : In 1987, when the Sunderbans National Park in West Bengal received the status of natural UNESCO World Heritage Site, many were unaware of the technical reasons behind this pride of Bengal getting the prestigious accreditation. Experts like Dr Raja Raut explained that one of the reasons for Sunderbans National Park being put on the UNESCO World Heritage Site list was because of its outstanding contribution to ecological and biological processes so necessary for the development of the marine ecosystem, terrestrial habitat and for the survival of different communities of plants and animals there. Another reason for the tag was that the Sunderbans National Park meets the criteria under the 'in-situ conservation of biological diversity', which in layman's language meansthe conservation of a species in its natural habitat and the maintenance and recovery of a viable population of species in their original place.This pattern of 'in-situ conservation of biological diversity' also includes threatened and endangered species, explained Raut. In the opinion of experts, meeting these two criteria was the prime reason for Sunderbans National Park being put on the UNESCO's prestigious list. They rubbished the argument that lobbying plays an important role in bagging such accreditations. According to them, lobbying might play a minor role on this count, but no amount of influencing can get a region the tag if the site does not fulfil the basic criteria, especially in the natural category. According to experts, Sunderban is unique because not only does it contain the world's largest mangrove forests it also has a range of forests and waterways scattered over the coastal belts of South 24 Parganas and North 24 Parganas. 'While being the largest halophytic mangrove forest in the world is definitely a criteria we also have to keep in mind that it is one of the most productive natural ecosystems. It has a range of forests and waterwaysthat support a huge diversity of fauna that includes threatened and endangered species,' an expert pointed out. In addition to that, the mangrove forest supports the largest population of Royal Bengal tigers unique for its capability of thriving in an amphibious environment and surviving suitably in both land and water, he added. 'The Royal Bengal Tigers are unique due to their capabilities of swimming long-distances and survive on a varied diet of fish, water-monitor lizards and even crabs. They have these capabilities as they adapted to their abode in the mangrove forestation,' the expert said. Another point that makes the Sunderban so precious is the fact that this mangrove forestation acts as a shelterbelt for the people of the region and protects them from severe climatic conditions. Apart from that, the rich natural resources of the Sunderban are the economic backbone of millions of people, whose primary source of livelihood is wood and honey collection, subsistence fishing and shrimp farming. The park is also immensely important to the local residents, the West Bengal government, the tourism sector and other stakeholders due to its huge revenue potential. However, this lure of the Sunderbans National Park has resulted in the mushrooming of real estate developments in the area, often illegally, by a section of dubious real estate developers. The illegal constructions often encroach upon and damage the mangrove forests, which are the backbone of the region. Many a times the courts have had to intervene and order the demolition of such illegal constructions there, which has resulted in unnecessary controversies and negative publicity for the reserve. /IANS