Thursday 12 April 2012

The elusive freshwater dolphin of the sacred Ganga

Written by Shubhobroto Ghosh

Think of the word dolphin and the immediate image that is conjured is one of Bottlenosed Dolphins in the ocean which has made them the visual representative of all dolphins. However it comes as a surprise to some people to learn that there are several species of dolphin, like the Gangetic River Dolphin, that are also found in freshwater systems, rivers and lakes. These animals are not as eye catching and attractive as their sea dwelling partners but nonetheless they are endangered and of great ecological importance. 

Six species of Freshwater dolphin
The Gangetic River Dolphin is one among six species of freshwater river dolphins that exist in the world today, found in rivers of Asia and South America. The Gangetic River Dolphin (Platanista gangetica gangetica) and Indus River Dolphin (Platanista gangetica minor) are the two sub species of freshwater dolphins found in India, Nepal, Bangladesh and Pakistan.
Echolocation
Gangetic River Dolphins have the long, pointed noses characteristic of all river dolphins. The teeth are visible in both the upper and lower jaws even when the mouth is closed. The snout thickens towards its end. The species does not have a crystalline eye lens, rendering it effectively blind, although it may still be able to detect the intensity and direction of light. Navigation and hunting are carried out using echolocation. They are unique among cetaceans in that they swim on their side.
Just 2000 aliveIn India, one can see these beautiful cetaceans along river reaches in Assam, Bihar, Jharkhand, Madhya Pradesh, Rajasthan, Uttar Pradesh and Bengal. Research studies under the Ganga Action plan in the 1980s estimated that around 6000 dolphins were present in its distribution range across the Ganga-Brahmaputra-Meghna and Karnaphuli river systems. Sadly today the population level is estimated to be around 2000.
Indicator species
Just like the tiger in a forest ecosystem, the Gangetic River Dolphin is an indicator species for the river ecosystem. It is at the apex of the food chain and is an endemic and rare charismatic animal found only in the Indian sub-continent. The animal has been known historically for ages and has a range of local names. The creature has been mentioned in the Babarnama; The Gangetic River Dolphin is also said to be the first animal that followed Bhagirath who was bringing the Ganga (Ganges).
The Gangetic River Dolphin is listed on Appendix I of CITES (Convention on International Trade in Endangered Species) and is classified as ‘Endangered' by the IUCN (International Union for Conservation of Nature). Over the years, WWF, in collaboration with other groups and the government has undertaken several initiatives to save this animal that has now been designated as the National Aquatic Animal of India.
WWF India initiated a conservation programme for the Gangetic River Dolphin in 1997. This began with a series of surveys and field visits to specific stretches and to surrounding villages in the habitat of this animal.

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