Ganges River dolphins (Platanista gangetica gangetica) occur in the Ganges-Brahmaputra River system primarily in India and Bangladesh. They are listed as Endangered by the IUCN due to a probable population decline of at least 50% over the last 50 years and projected future population declines. No quantitative estimates of abundance are available for the Ganges River
dolphin although an overall abundance of about 2000 has been suggested. Dolphins have been extirpated from the upper reaches of many rivers, the population has been fragmented by
irrigation barrages and dry season habitat is further reduced by diversion of water. In comparison to the Ganges, the Brahmaputra River is less degraded and is therefore of great importance for persistence of the subspecies. For this reason, a recent proposal by Oil India Ltd. to initiate seismic exploration (using explosives and airguns) along the bed of the Brahmaputra River to prospect for oil has potentially disastrous implications for Ganges River dolphins. This project was designed to provide missing baseline information on distribution,
abundance, behaviour and acoustics of Ganges River dolphins in the Brahmaputra River and suggest suitable locations to establish protected areas.