Thursday, 1 May 2014

Brahmaputra’s Dolphins




A view of the Brahmaputra river from our boat

An interesting geographical detail that is a cause of surprise to many is that the river Brahmaputra is not only the biggest river in India, but is also the only river in the country that is considered to be masculine. While all the other Indian rivers are considered feminine, which is evident from their feminine names, 'Brahmaputra' refers to the son of the god of creation,Lord Brahma. The gargantuan river flows through three countries, Tibet, India and Bangladesh and is known by different names – Tsangpo in Tibet, Dihang in Arunachal Pradesh where it enters India, Luit or Brahmaputra in Assam, and finally it splits into two rivers called Padma and Jamuna in Bangladesh.


It is this behemoth river that is home to the river dolphin that goes by the scientific name, Platanista gangetica and is locally known as ‘Hihu’ in Assam. I was around six years old when my father took me on a river cruise on one of the many ‘floating restaurants’ that ply on the river in Guwahati, when I spotted my first river dolphins. We were just soaking in the scenic beauty of the small river islands that dot the halcyon waters of the Luit, when my father suddenly pointed out these small, grey-coloured humps in the water to me. Boy, was I excited!The dolphins were swimming alongside our boat and occasionally came up for air, making it a spectacular and unforgettable sight. I was astonished to learn that these endearing mammals are blind, a result of their sonar sense being highly developed and hence rendering their eyes useless, making them unique from other dolphin species. As a result, they cannot be trained like marine dolphins and do not survive in captivity for long.


The number of of these dolphins has dwindled dramatically over the last few years, the major threat being accidental killing caused by their entanglement in the fishing nets. Fish constitutes an important part of the diet of the people of Assam and its neighbouring areas, and needless to say, fishing is a major economic activity here. Apart from fishing nets, poaching of these dolphins for their meat and oil is another factor leading to the decline in their population. In Eastern Assam, the ‘Missing’ tribe kills them for their meat, whereas in Upper Assam, they are slaughtered for their oil, which is used as bait for catfish. Some living in remote villages also believe that dolphin oil has medicinal values and use it for treating rheumatism, as a result of which dolphin oil has high market value. During the high flood season, the dolphins migrate from the main river to the tributaries and they migrate back when the water recedes. The fishermen make use of the migratory movement by blocking the mouths of the tributaries with nets to trap the dolphins. Yet another factor having a fatal repercussion on these creatures is non-availability of their food, which includes a variety of fish, crustaceans, prawns etc due to over-fishing. Water development projects like dam construction affect the river’s ecological system by degrading the habitat of all the aquatic creatures and hindering their migration. Moreover, the rate of reproduction of this species is very less, a female giving birth to a single calf only once in 2-3 years, after attaining sexual maturity at the age of 10-12 and gestating for a period of 9-12 months.


Various non-government organisations or NGOs are working towards this issue in this region. I came across one such NGO called 'Aaranyak' recently while trying to learn more about the ecological issues ailing the area. They have worked extensively to sensitize the villagers about the impact of over-fishing and have taught them various alternative ways of fishing which do not require dolphin oil or meat as bait. These measures have helped control the dwindling population of these mammals to some extent. More people should get involved in these efforts and spread the word about restoring the pride of the Brahmaputra.