Saving the soans
The World Conservation Union has classified the Ganges river dolphin as an endangered species globally. The World Wildlife Fund recognises it as a flagship species for freshwater ecosystems and the Convention on International Trade in Endangered Species of Wild Flora and Fauna as a species by trade in Appendix I.
In Nepal, the National Parks and Wildlife Conservation Act, 1973, Section 10, protects this species, listing among 27 protected mammals under Schedule I.
The Ganges river dolphin, also known as soans, is the only cetacean found in the rivers of Nepal, which was once distributed in the Mahakali, Karnali, Narayani and the Koshi river systems. But the construction of the dams and other water development projects such as hydropower and irrigation systems, and an intensive fishing trend, water pollution, and extensive human disturbances have decreased its abundance. As a result, no dolphins have been recorded in the Mahakali river, though there have been occasional sightings in the Narayani river. The dolphins now are restricted only to the Karnali and the Koshi river systems.
A WWF Nepal study on the status and distribution of the dolphins in 2005/06 found only three to four dolphins in the Karnali river. Information on the status of the dolphin population in the Koshi river, the biggest river in Nepal, is scanty, and no effective measures are in place to stem its decline. Such limited information is the major constraint for the protection and conservation of this endangered mammal.
The dolphin status in the Koshi river has become a matter of major concern. As a part of Masters project thesis at the University of Klagenfurt, Austria, I conducted an extensive field survey from October 2006 to January 2007, during which I counted 15 dolphins — 10 adults and five sub-adults. The research was carried out in a total length of 36 km from Chatara and the distance two kilometres downstream of the Koshi Barrage. The hotspot and the potential sites of the dolphins in the river were identified and mapped to make suggestions for its protection. All the dolphins were found in a stretch of two kilometres downstream of the Koshi Barrage.
Dolphins were not sighted in the river section upstream of the barrage. However, local communities reported sightings of the species around Rajabas during the same period in 2006. A local bird watcher group also sighted dolphins in the same area in 2006. And a recent incident of dolphin poaching by the local villagers for its meat in a nearby tributary during the monsoon season of 2006 also supports the existence of dolphins in the area.
The study also identified the southern section of the barrage as a hotspot and Chatara, Rajabas, Kushaha and the Third Tower areas as potential sites of the species.
The Koshi river is subjected to severe anthropogenic stresses causing pronounced habitat degradation in the area. Fishing in Chatara, Rajabas, Srilanka Tappu areas, where the sightings of the dolphins are occasionally reported, is significant. The barrage area is also subjected to intensive exploitation by fisheries, which lead to the decline of the fish population, especially the southern section of the barrage is highly stressed. The use of gillnets, dragnets and cast-nets for fishing is common in the areas. Locals during study said that a juvenile dolphin was caught in a gill net few years ago downstream of the Koshi Barrage. The Koshi Barrage, a low-gated 1,150 metre dam with a ladder that is inefficient for fish migration, is posing to be a threat to upstream river dolphins. It prevents migration of dolphins, increasing their vulnerability. It has altered the primary habitat of the species by making the river section upstream of the barrage like a lake and eliminating the counter currents downstream of the barrage where the prey fishes live and the dolphins forage in the areas.
Scientists say that the effects of subdividing a single population into non-interacting insular units increase their vulnerability to environmental, demographic, genetic and etiological threats, and the Koshi Barrage is not an exception.
Moreover, ineffective law enforcement and lack of awareness about river dolphins among locals have also contributed to the population decline of dolphins in the Koshi river.
Without an immediate and concentrated effort, soans will almost certainly become extinct locally, and nationally in the future.
Single meal protection efforts may not be enough for the conservation of this species. An integrated approach should be adopted not only relying on legislation or focusing on the sole river dolphins and their habitats but also maximising economic and social wellbeing in a sustainable manner to protect the remnant dolphin population.
A trans-boundary conservation effort should be initiated for the protection of this species. Integrating the southern section of the barrage into the buffer zone area of the reserve could be an option for protection of dolphins. The area should be conserved and managed under Buffer Zone Management Regulations of Nepal. In addition, a sustainable ecotourism, incorporating all tourists’ attractions of the area should be implemented in coordination with the local community and the Koshi Tappu Wildlife Reserve. This could be an effective move in favour of dolphin conservation as well as community development in the area.
An ecosystem-based dolphin conservation plan should be developed and implemented at the earliest.
The dolphin protection in the Nepali rivers has now become a major challenge for the entire conservationists, the Nepal government, including the general public.
(The author holds a Maters degree in Management of Protected Areas from the University of Klagenfurt, Austria, and is a Conservation and Scientific Intern at the United Nations office in Bonn, Germany and can be reached at email@example.com; firstname.lastname@example.org )