Mangroves along the coastal stretch of the Bay of Bengal: Present status

Abstract

With the help of high resolution satellite data (SPOT products), it has been possible to portray on maps the present distribution of main mangrove types and sub-types of the Bay of Bengal coastline. New figures have been given for the mangroves of each concerned country especially for Myanmar. The present ecological status of mangrove ecosystems in the three major deltas, the Godavari, the Ganges and the Irrawaddy are totally distinct. In the Godavari delta (India) mangroves are receding in area and biomass; in the Ganges, the Sunderbans (India and Bangladesh) are evolving very slowly in size but an important species substitution is in progress; in the Irrawaddy (Myanmar) mangroves are in continuous decline. The present distribution and status of each mangrove type is the result of direct and indirect anthropic factors. Conversion to agriculture, reafforestation, fishponds constructions, forest exploitation are now easily detected from space. Conversely, indirect impacts, such as freshwater diversion or chemical pollution, cannot be monitored with sensors operating in the visible part of the electromagnetic spectrum.