Reuters guardian.co.uk, Wednesday 17 August 2011 10.16 BST
Entanglement in fishing nets and high calf mortality thought to be behind decline in the small numbers of Irrawaddy dolphins in the Mekong
The Irrawaddy dolphin population in the Mekong River is at high risk of extinction, with numbers estimated at 85 and the survival of new calves very low, WWF said on Wednesday.
Fishing gear, especially gill nets, and illegal fishing methods involving explosions, poison and electricity all appear to be taking a toll, with surveys conducted from 2007 to 2010 showing the dolphin population slowly declining.
“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 WWR's freshwater programme.
“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.”
The Irrawaddy dolphins live in a 190km (118mile) section of the Mekong between Kratie, Cambodia and the Khone Falls, which are on the border with Laos.
Research also shows that the population of dolphins in a small transboundary pool on the Cambodia-Laos border may be as few as seven or eight, 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, director of WWR’s freshwater programme.
Dolphins once ranged from the Mekong delta in Vietnam up through the Tonle Sap (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 south-east Asia, and in three rivers: the Mekong, the Ayeyarwady in Burma, and the Mahakam in Indonesian Borneo.