The WWF warns that Asia's river dolphin populations are in severe decline due to polluted water, dams and entanglement in fishing nets and has launched an initiative to save some of the world's most threatened mammals.

The WWF delivered the stark warning on the eve of World Water Day, which falls today.

According to the global conservation organization, this is all the more worrying as river dolphins are key indicators of a river's health and of the availability of clean water for the people living along its banks.

The WWF lists industrial, agricultural and human pollution, as well as dams, which restrict dolphin movement, as some of the major threats facing the aquatic mammal.

Accidental catches by fishermen are also contributing to the decline of dolphin populations.

"River dolphins are the 'watchdogs' of the water," said Jamie Pittock, director of the WWF's Global Freshwater Program. "The high levels of toxic pollutants accumulating in their bodies are a stark warning of poor water quality. This is a problem for both dolphins and the people dependent on these rivers."

The latest evidence shows that the Yangtze River dolphin is particularly threatened with only 13 individuals left in China's largest river. Another study by WWF India revealed that there are fewer than 2,000 Ganges River dolphins along the 6,000-kilometer-stretch of the Ganges and Brahmaputra river system.

A similar number of Irrawaddy dolphins remain in Asia-Pacific waters while in Pakistan, there are no more than 1,100 dolphins scattered in five populations.

River dolphins swim in some of the world's most densely populated river basins, including the Ganges and Indus river basins, where one tenth of the world's people live.

"Clean water is not only vital for the survival of the river dolphin, but also for the quality of life of millions of the world's poor," Pittock said. "Conserving biodiversity and alleviating poverty are inextricably linked."

The WWF is working with authorities and local people along the Ganges, Yangtze and Indus rivers to improve water quality and the dolphins' habitat.

For example, through the WWF River Dolphin Conservation initiative, local communities are being encouraged not to pollute rivers with household detergents and prevent toxic run-off by using natural fertilizers, such as cow manure. In the Ganges, such an initiative has increased dolphin numbers from 22 to 42 over the past decade along a 164-kilometre stretch of the river.

WWF China's Yangtze Dolphin Conservation Strategy has implemented countermeasures addressing the threats posed to dolphins, including mitigating non-point pollution (pollution which cannot be traced back to a single source), setting up a dolphin conservation network, developing alternative livelihoods for fishermen, and promoting organic agriculture.

At Tian'e-Zhou Oxbow in Hubei Province, the site of a national dolphin reserve, a WWF project has resulted in the re-opening of a dyke that has cut the lake off from the Yangtze for five years.

These methods follow the "ecosystem approach," which differs significantly from past practices on Yangtze dolphin conservation by advocating the protection of habitats or ecosystems, rather than focusing on the species alone.

With one of the UN's Millennium Development Goals being to halve the number of people without safe water supplies and sanitation by 2015, the WWF is calling on governments, local communities, water management agencies and investors to protect areas of high biodiversity to ensure that they provide clean water for people and nature.

(China Daily March 22, 2005)