Entanglement in fishing nets, low calf survival rates and a steady degradation of the creature’s habitat are threatening the estimated 85 Irrawaddy dolphins left in Cambodia and Laos, WWF said on Wednesday.
The Irrawaddy dolphins live in a 190 km (118 mile) section of the Mekong between Kratie, Cambodia, and the Khone Falls, which are on the border with Laos.
Fishing gear, especially gill nets, and illegal fishing methods involving explosions, poison and electricity, all appear to be taking a toll.
Surveys conducted from 2007 to 2010, showed a slow decline in the dolphin population, the WWF added.
“Evidence is strong that very few young animals survive to adulthood, as older dolphins die off and are not replaced,” said Li Lifeng, director of WWF’s Freshwater Programme, in a statement.
“This tiny population is at risk by its small size alone. With the added pressure of gill net entanglement and high calf mortality, we are really worried for the future of dolphins.”
Research also shows that the population of dolphins in a small pool on the Cambodia-Laos border may be as few as 7 or 8, the WWF added, despite the fact that Irrawaddy dolphins are protected by law in both nations.
The group called on Cambodia to establish a clear legal framework to protect dolphins, including steps such as banning gill nets if needed.
“Our best chance of saving this iconic species from extinction in the Mekong River is through joint conservation action,” Li said.
But the Cambodian official responsible for caring for the country’s Irrawaddy dolphins criticised the group’s research methods and insisted there remained “about 155 to 175” of the animals in the Mekong.
“WWF does not do proper scientific research. I do not know what kind of methodology they are using,” Touch Seang Tana, chairman of Cambodia’s Commission to Conserve Mekong River Dolphins and Develop Eco-tourism, told AFP news agency.
He added that according to his findings, dolphin numbers were slowly improving. “Last year, we had 12 newborns,” he said.
The Cambodian government and the WWF clashed over the same issue in 2009, when the WWF estimated there were just 64 to 76 Irrawaddy dolphins left in the river, partly because of pollution and illegal fishing methods.
The group said its current estimate of 85 dolphins was higher because of better monitoring techniques, rather than because the population had increased.
Dolphins once ranged from the Mekong delta in Vietnam up through the Tonle Sap in Cambodia, and then up tributaries into Laos, but were shot by soldiers and harvested for oil in the past.
Irrawaddy dolphins are found in coastal areas in South and Southeast Asia, and in three
rivers: the Mekong, the Ayeyarwady in Myanmar, and the Mahakam in Indonesian Borneo.