Science and Culture (ISSN 0036-8156), Vol 68, no 9-12, 2002, p 309-321 Sea Level and associated changes in the Sundarbans Sugata Hazra, Tuhin Ghosh, Rajashree DasGupta and Gautam Sen School of Oceanographic Studies, Jadavpur University, Kolkata 700032, India E-mail: iczom@vsnl.com Introduction Sundarbans, the only mangrove tiger-land of the globe is presently under threat of severe coastal erosion due to relative sea level rise. The once largest prograding delta which registers the highest species diversity in terms of mangrove and mangrove associate flora and fauna is showing evidences that suggest the rich biodiversity is under threat. Increasingly, this deltaic island system is facing degradation due to natural and anthropogenic changes. Frequent embankment failures, submergence and flooding, beach erosion and siltation at jetties and navigational channels, cyclone and storm surges are all making this area increasingly vulnerable. In addition, alarming growth of population in this ecologically sensitive and fragile niche has posed a major threat for its very existence. Wide scale reclamation, deforestation and unsustainable resource exploitation practices have together produced changes in the physical and biological dynamics of the coastal system. In the present research, we have tried to observe the changes if any, in the physical dimensions of this coastal ecosystem over a period of 10-20 years. For this purpose we have selected components such as i) temperature regime, ii) occurrence of high intensity climatic events like cyclones, iii) shoreline change and iv) sea level change. Simultaneously, biological and social aspects like changes in forest cover and land use patterns, food grain, fish production and population pressure have been studied to understand the vulnerability of the ecosystem with respect to possible climate change. Eventually, a mathematical model developed by the school has been applied to predict future shore line positions of the Sagar island in different sea level rise scenarios. The possible impact of such changes on the other bio-physical and socio economic dimensions of this coastal ecosystem, however, remains to be investigated further.