The Mekong river dolphins are extinct

Pollution in Southeast Asia's largest river is pushing the population of extinct Irrawaddy dolphins, according to a warning from the International Fund for Nature Protection (WWF).

An Irrawaddy dolphin.Photos: marinespieces.org.

The Irrawaddy dolphin (Orcaella brevirostris) lives on the 190 km stretch of the Mekong River between Laos and Cambodia. According to the WWF report, since 2003, there have been 88 deaths and 60% of them are juvenile dolphins. WWF estimates that there are only 64 to 76 individuals still living in the Mekong River.

Doctor Verné Dove, author of the report and a veterinarian working for WWF Cambodia, said: 'Anatomical analysis shows that fish died from infection. This will not be fatal if the whale's immune system is not impaired by environmental pollution '.

Researchers found pesticides, mercury and other toxic substances when removing baby dolphin carcasses. These substances can pose a health risk to people living along the Mekong River as they eat fish and use dolphin-like river water.

According to Dr Dove, these substances are widely dispersed in the environment and thus pollution may originate from countries where the Mekong River flows. WWF Cambodia is investigating their origin.

According to WWF, mercury from the gold fields has flowed into the Mekong River and reduced the immunity of dolphins, making them more susceptible to infectious diseases. Director of WWF Cambodia, Seng Teak, said, "There is a need for a cross-border preventive health program to manage infected organisms, thereby reducing the number of dead fish every year."

Inbreeding is also a factor in the immunity of the Mekong dolphins. 'The Mekong dolphin is isolated from the same species in other waters on the planet, so people need to help them. Science has proven that if the environment of mammals is protected, their numbers will increase significantly , 'Mr. Teak said.

Several thousand Irrawaddy dolphins used to swim in the Mekong. Although considered sacred animals in Cambodia and Laos, their numbers decline year after year by the use of rampant fishing nets. Recently the Cambodian government has advocated to protect Irrawaddy dolphins for ecotourism development. Therefore, net fishing on the Mekong is limited. The Cambodian government hopes its measures will help the dolphin population increase in the coming years.

Irrawaddy dolphins only appear in five freshwater environments around the world, including the Mekong. This fish lives in a 190 km long river in Laos and Cambodia. Since 2004, the Irrawady dolphins living on the Mekong River have been categorized as the most threatened species in the IUCN Red List.

The Mekong River flows through Cambodia, Laos, Myanmar, Thailand, Vietnam and China's Yunnan Province. This is one of the largest aquatic resources in the world. Each year it supplies people with about 2.5 million tons of fish, equivalent to more than $ 2 billion. The river also provides 80% of animal protein for 60 million people living along its low basin.