Prof Dr. R K Sinha

Action is needed to make sure that river dolphins survive. Of the four freshwater dolphin species in the world, three of them are found only in Asia. All three species are classified as "Critically Endangered" or "Endangered". Listed in order of the most threatened to the least, are the baiji (Lipotes vexillifer) in the Yangtze River of China (population few tens), the bhulan (Platanista minor) in the Indus River of Pakistan (population about 1,100), and the susu (Platanista gangetica), with a population about 2,500. The fourth freshwater species, the boto (Inia geoffrensis), is found in the Amazon River system in South America, population of which is estimated to be about 5,000.

The Ganges River dolphin (Platanista gangetica), commonly known as susu, is found in rivers originating from the Himalayas and flowing through Nepal, India and Bangladesh. Today this rare freshwater species is highly endangered because of shrinkage of habitats, fragmentation of population and heavy mortality. Although the total population of the susu is over two thousand, isolated subpopulations, especially in Nepal and in the Karnaphuli River system of Bangladesh, have become extinct or been critically reduced by the barrier effects of dams and barrages. Action necessary to save river dolphins includes:

Ecosystem Integrity

To conserve river biodiversity, the whole ecosystem should be taken into account, from the upstream watershed to downstream alluvial channels. Preserving the natural attributes of aquatic ecosystems is essential for conserving dolphins and other life forms. Programmes for aquatic wildlife can be linked to preserving the clean water and productive fisheries that are essential to people.

Watershed and Forestry Management

Sustainable management of forests in catchment areas is critical for maintaining the ecology of large rivers. Deforestation affects the rate of sedimentation, the stability of the stream, the input of biomass necessary for aquatic production, and the availability of woody debris. Reforestation can help restore rivers which have already been degraded by the over-harvesting of forest products.

Public Awareness

Local support for dolphin conservation efforts is vital. Local people should be encouraged to become involved in awareness programmes that focus on the cultural, economic and ecological value of river life. Whenever possible, river bio-diversity conservation programmes should be linked to projects that also benefit local fisheries. Popular media, including videos, posters, comic books, radio, etc. should be used to publicise the conservation needs and value of dolphins, especially targeting communities near protected areas.

Research

The Ganges and its tributaries have complex and interconnected ecological processes that remain largely a mystery. Scientifically credible research can greatly help the development of effective conservation strategies. Local scientists should be involved in all phases of research activities. Hiring local people as boatmen and observers helps to establish two-way communication between researchers and river communities.

Information is particularly needed on the distribution, abundance, and habitat of the dolphins. Regular monitoring of their status and mortality, as well as studies on their behaviour, including territorial requirements, will be an essential component for formulation of conservation strategies. Appropriate research on behaviour is also needed before a dolphin "swimway" can be designed and tested. No technical solution is currently available to mitigate the barrier effects of dams or barrages on river dolphins.

The recent discovery of an alternative to dolphin oil as fish lure, which has been tested in the field for three consecutive years at Patna and other places, will go a long way to help conservation, while sustain the oil fishery in the Ganges and Brahmputra rivers.

Water Development

In evaluation options for water development, four basic principle of river ecology must be considered -

1. There is no "surplus" water. Any large-scale withdrawal will have ecological consequences.

2. The floodplain is an integral part of the river.

3. An alluvial river must be allowed to change its course.

4. Rivers need to maintain their natural variability.

River biodiversity must be considered when assessing the impacts of planned water developments. Adequate information on the pre-development ecological conditions of the river is essential. Environmental impact assessments should be used for comparison between projects and for post-development monitoring. If the impacts of a water development project are judged to be severe and cannot be reduced to acceptable levels, then the option of not constructing the project should be considered.

Protected Areas

Protected areas can be a mechanism for more focused efforts to conserve dolphins. The extent and configuration of protected areas should be based on information on stock structure, movement patterns, suitability of available habitat for aquatic wildlife, and potential for educing threats. Implementation requires the support of local people and site-specific management plan.

Legislation and Enforcement

Legislation that addresses issues such as directed killing, fisheries regulations, accidental killing, discharge of harmful pollutants, and the environmental impact of development projects can be a useful tool for conservation. But legislation without awareness and enforcement is meaningless.

Traditional Fishing Methods and Community Management

Preserving aquatic biodiversity requires the availability of sufficient prey and an environment free from the dangers of accidental entanglement in nets or injury from explosives, electricity, and poisons. Traditional selective fishing methods, such as single hook and lines, cast-nets, and seine nets, often reduce accidental deaths and can provide a sustainable supply of fish to local communities. Non-selective fishing methods should be discouraged.

Local people are more likely to support measures for protecting dolphins if they are linked to providing them with sustainable benefits. Ideally the enforcement of fishing regulations should be accomplished on a community level.

Ecotourism

Well-managed tourism can contribute to conservation while providing employment and revenue to local communities. Local people should be trained and hired as guides, boatmen and support staff. However, tourism must be managed to ensure that it does not contribute to environmental, degradation or cultural disintegration. A portion of all profits should be invested in local conservation and social development. Programmes that use participating tourists to accomplish research and conservation goals should be encouraged. For example, dolphin watch tourism is being promoted in Chilika Lagoon where only about 30 Irrawaddy dolphins survive.

Institutional Support

All river dolphins need institutional support for their long-term survival. Compared to efforts to save other wild animals, not enough attention is being paid to species living in rivers, despite their populations being much lower. There is a serious need for continuous research and conservation efforts to save the animals from extinction.