Study: Pollution killing rare Irrawaddy dolphins

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Associated Press

By MICHAEL CASEY , 06.18.09

BANGKOK -- Pollution in the Mekong River is putting the rare Irrawaddy dolphin in danger of disappearing from Cambodia and Laos, according to a study by an environmental group released Thursday.

A Cambodian government official, however, rejected the finding and demanded that the group apologize.

The World Wide Fund For Nature Cambodia said it has documented 88 deaths in the past six years of the Irrawaddy dolphin or Orcaella brevirostris along a 118-mile (190-kilometer) stretch of the Mekong River.

The Irrawaddy dolphin, which is related to orcas or killer whales, frequents large rivers, estuaries, and freshwater lagoons in South and Southeast Asia. The population in the Mekong is now believed to include as few as 64 members, the WWF said, down from 80 to 100 just three years ago.

Researchers from WWF Cambodia said they found levels of the pesticide DDT in the bodies of dead dolphin calves from the Mekong that were 10 times higher than in a similar population in India, plus environmental contaminants such as PCBs. They also found mercury, a toxin used in gold mining that can compromise the immune system of marine animals, they said.

The group said it was investigating the source of the pollutants, noting that many young calves died of bacterial diseases that only occur when immune systems are damaged. Many had black and blue lesions on their necks.