The last population assessment survey (2008) of the Gangetic river dolphin in the entire Brahmaputra river system has shown a marginal increase in its number. In 2005, the population of the endangered aquatic mammal was estimated at 250, which, according to the latest survey, has increased to 265. This was disclosed by the members of Aaranyak, a non-government environmental organisation, which has been working in the field of dolphin conservation, among others, for several years. Speaking to media persons at the Guwahati Press Club today, Dr Bibhab Talukdar, secretary general, Aaranyak, said that the organisation, as an attempt to reduce the mortality of dolphins, was developing a Dolphin Conservation Network involving 40 community-based trained volunteers to monitor and conserve dolphins and their habitats scientifically and systematically in 40 identified dolphin hotspots across the Brahmaputra Valley. On the threat perceptions, Dr Talukdar said that they had identified mortality of dolphin through gill net entangling and poaching for oil, habitat loss, and over-fishing in dolphin hotspots as the major threats for the declining of the dolphins in the BRS. It further identified the proposed seismic survey in the Brahmaputra river bed by OIL and the construction of water development projects as potential threats to the dolphins of the Brahmaputra river system. "We have come to know that river dolphins are present in 26 per cent of the proposed seismic survey area, which is a very fatal sign,' said Dr Talukdar. "Being a scientific and industrial research organisation, we are not against any development issue, but at the same time we strongly oppose the gross damage to our environment in the name of development,' he pointed out. "Since there is no record of any study on the impact of seismic survey in any river dolphin-inhabited rivers in the world, therefore, Aaranyak is in the favour of conducting a detailed impact assessment study prior to giving any clearance to the proposed seismic survey,' he asserted. Due to this campaign, which was supported by organisa-tions world-wide, the Ministry of Environment and Forest finally stopped clearance to OIL and directed OIL to conduct a detailed study on the potential impact of the seismic survey by a high-level multi-disciplinary advisory group.