Ganges River Dolphin (Platanista gangetica)
Mohamed bin Zayed Species project number 12054035
Asian river dolphins are among the most threatened large vertebrates, because the regions they inhabit have high human population density, resource overexploitation and environmental degradation, with escalating pressures on local biodiversity and diminishing ecosystem services. Following the extinction of the Yangtze River dolphin, the Endangered Ganges and Indus River dolphins are now the world's most threatened freshwater cetaceans.
Ganges river dolphin Platanista gangetica, also known as Susu, is an endangered freshwater dolphin distributed thorough out the Ganges, Brahamaputra and Karnaphuli rivers and their tributaries of Nepal, India and Bangladesh (Jones 1982, Sinha 2000). Although dolphins were once abundant in Nepal throughout the Koshi, Narayani, Karnali and Mahakali rivers and their feeder streams (Jnawali and Bhuju 2000), but due to construction of low gated dams across river systems for irrigation and flood control, over exploitation of prey species, illegal killing and wide range of other human disturbances, the populations are now more or less restricted to Karnali and Koshi river systems (Smith 1993). The only river in Nepal that supports an even questionably viable dolphin population is the Karnali, upstream of the Girijapur barrage in India, but this population may become extinct in the absence of conservation action on both sides of the Nepal/India border (Smith 1996). In the past there were fewer than 100 dolphins in Nepal, with the group of about 20 in the Karnali River above Chisapani being the largest single concentration (Jones, 1982; Reeves and Brownell, 1989).
Dolphins are particularly threatened in the upstream reaches of the smaller tributaries, where populations are often isolated behind barrages and are more vulnerable to human activities because of the reduced habitat area and perhaps the most endangered populations are in Nepal (Sinha et al 2000). The upstream isolated sub population inhibiting in the Karnali are endangered by habitat degradation, segregation of breeding groups by the barrage in Kailaspuri India, reduction in fish prey populations and interference in spawning migrations (Shrestha, 1989). A high dam has been planned for some time just upstream of the dolphins' current (or at least recent) range in the Karnali River, Nepal. If built, this structure would almost certainly eliminate the small amount of dolphin habitat in Nepal's last river with a potentially viable dolphin population (Smith and Reeves 2000). Disturbance and environmental degradation associated with geotechnical feasibility studies and bridge and road construction for the dam already may have contributed to a decline in the number and range of dolphins above the Nepal-India border (Smith 1993, Smith et al. 1994).
In spite of being endangered by tremendous threats, very little information is known about the ecology and status of dolphin in the Karnali River. No scientific status survey has been carried out to update information over past few years, and lack of updated information on dolphin is becoming a major constraint to its protection and management. Successful strategies need sound understanding on the status, ecology and conservation threats to facilitate the recovery of depleted populations, reverse the trend of decreasing population. Thus this project is designed to help provide the updated information on population status, distribution and habitat ecology of dolphin in the Karnali which in turn will help to identify appropriate conservation measures needed for conservation planning. The main objectives of this projects are to determine the population status, distribution, habitat ecology and conservation threats of dolphin, strengthen the capacity of stakeholder, assist government in conservation planning and enhance the community participation in conservation. The findings of the research not only will be helpful in recent conservation planning but also will act as baseline information for further research in future. This project has been initiated with a view to develop comprehensive project with leading research, applied conservation action, capacity building and environmental education. The project is implemented by Nepal Dolphin Conservation Society(NDCS) with financial support from The Mohamed bin Zayed SPECIES CONSERVATION FUND.
Project 12054035 location - Nepal, Asia