The Hindu Business Line : Troubled dolphin waters

Every day, thousands flock to worship the Ganges, worshipfully addressing the river goddess as ‘Ganga Maiyya (mother)’. But few spare even a moment’s thought for one of this holy river’s most famous, and most endangered, denizens — the Gangetic dolphin. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) has included Gangetic dolphins in its list of endangered species owing to their rapidly declining numbers.

The dolphins produce a magical effect as they spring out of the water for a couple of seconds before diving in again, resurfacing every three minutes for air! The locals fondly call them susu, thanks to the sound the dolphins make when they spring up into the air.

The survival of the Gangetic dolphin, orPlatanista gangetica, is closely tied to the survival of the river and its ecosystem.

The river dolphin has no eye lens and uses the eyes as a direction-finding device. It uses echolocation to track food and its sensitive snout is used to probe for fish, shrimp, and other organisms at the river bottom.

The species can be found only in the freshwaters of the Ganges, Brahmaputra, Karnaphuli and Meghna rivers in India and Bangladesh.

Commercial fishing, large-scale irrigation and pollution have drastically shrunk the dolphin’s habitat.

There are some 30 cities, 70 towns and thousands of villages located along the banks of the Ganga. Nearly all of the sewage from these population centres — over 1.3 billion litres per day — passes directly into the river, along with thousands of animal carcasses, mainly cattle, according to Dr Sandeep Kumar Behera, Coordinator - Freshwater Species, Freshwater & Wetlands Programme, WWF-India. Annually the river is choked with about 260 million litres of industrial wastewater, largely untreated, discharged by hundreds of factories, and the runoff from the more than 6 million tonnes of chemical fertilisers and 9,000 tonnes of pesticides used by cultivators in the Ganga basin, says the WWF report. Partially burnt corpses and ashes of cremated bodies are also disposed in the river as per Hindu rites.

“To address these issues WWF established a pilot demonstration project along a 165-km stretch of the upper Ganga, in Uttar Pradesh, to develop a methodology for tackling the threats to one of the most ecologically valuable stretches of the Ganga system. This is known to support one of the highest-remaining densities of Ganga river dolphin — an indicator of the relatively good health of the ecosystem in this location,” says Behera.

Irrigation canals in the Ganges river system may have brought prosperity to the river basin, but have proved to be a bane for the dolphins. Several large tracts of the river have become too shallow for the dolphins to survive. According to the WWF report, the endangered river dolphins are now divided by dams into isolated groups.

There has been little research on the dolphins and no proper census on their population and migration patterns. Experts call for year-round surveillance to help determine the home range of dolphin herds.

WWF is persuading local communities to use natural fertilisers instead of chemicals and to not dump waste into the river. Efforts are also being made to try and ban commercial fishing and sand-mining activities along the 160-km stretch inhabited by the dolphins.

WWF and its partners are evolving a comprehensive education programme using the dolphin to foster deeper understanding of the river ecosystem and to promote simple conservation measures. Take, for example, the replacement of chemical fertilisers with cattle dung. Public opinion was largely swayed by the influence of religious leaders and other respected community figures. Although there was no direct economic incentive for local people to change their attitudes or behaviour, they realised that they stood to gain from the increased fish production in a healthier river system.

According to Behera, “The project established a ‘presence’ in each village through regular visits by local volunteers, NGOs and WWF staff. This resulted in the gradual development of trust and understanding of the project’s aims.”

In a report concerning the future of Gangetic dolphins in India, Behera comments, “There are river interlinking projects which are being planned and if they are implemented, it could pose a serious threat as it would increase the number of barrages along the river. There is a need to develop a database on existing and planned dams in the region that affect the dolphin populations and provide recommendations accordingly.” By identifying and promoting safe, effective and affordable alternatives, we can save the dolphins.