Threats to the Ganges River Dolphin
© Abdul Wakid
• There are 168 dams planned for north east India, five of which are planned on rivers known to be important for river dolphins.
• The dams are likely to have a serious long term impact on the river dolphin population by:
1. Decreasing water levels
2. Increasing sediment load
3. Fragmenting the habitat
• A recent paper on the impact of Dams on river dolphins (1.3 MB).
• Fishing in the Brahmaputra River has occurred for hundreds if not thousands of years.
• The fish stocks are now severely depleted, reducing the amount of prey available for the river dolphins.
• Also, the river dolphins are getting entangled in fisherman’s nets, and are killed by being held under the surface of the water.
• There is a high level of conflict between fishermen and river dolphins as they both concentrate in areas where most fish occur.
• River dolphins are poached for their oil and meat by some local communities.
• Dolphin oil is used either as a lure to catch catfishes or as a medicine for rheumatism.
• It is essential that the use of dolphin oil is banned.
• It is important that dolphin oil fishermen are given an alternative bait so that illegal poaching and trade does not continue.
• The Brahmaputra River system is severely polluted by:
1. Agriculture: Pesticides and fertilisers used in tea gardens run off the land and enter the river system.
2. Industry: A number of industrial developments pump untreated waste products into the Brahmaputra River, causing severe industrial pollution.
3. Human: There is no sewerage system in many towns, so all human waste will end up in the river.
• The level of sand mining in the Brahmaputra River system has increased greatly over the last 20 years.
• Sand mining increases turbidity and sedimentation, which reduces the suitability of the habitat for aquatic fauna and can reduces foraging success.
• Mechanised sand mining is even more destructive and needs to be controlled.