Ray of hope for critically endangered Mekong dolphin but mega-dams threaten its chances of survival

Posted on November, 10 2015

A new population survey gives hope for Irrawaddy dolphin recovery in the Mekong
Cambodia, Phnom Penh – Years of effective conservation work has slowed the rapid rate of decline of the critically endangered Mekong River Irrawaddy dolphin, providing a glimmer of hope for its future – according to the latest data.
A new population survey by WWF and the Cambodian government found that the dolphin population had fallen to 80 – five fewer than in 2010, indicating that the species’ annual rate of decline has slowed from approximately seven per cent per year in 2007 to less than two per cent in 2015. This is the result of years of work by the government and WWF to protect their habitat and remove illegal gill nets, a major cause of dolphin mortality.
“It’s not yet time to celebrate, but we have reason to hope that the Mekong’s majestic dolphins are on their way back,” said Sam Ath Chhith, Country Director of WWF-Cambodia. “We need to re-double our efforts to reduce the mortality rate by protecting the dolphins from illegal gill net fishing and by ensuring that the destructive Don Sahong Dam and others like it are not built.”
The survey also showed that the recruitment rate, the number of juvenile dolphins reaching adulthood, has distinctly improved giving further hope for the survival of species. 
“The survey gives us an accurate number of the Mekong Irrawaddy dolphin, which is one of our country’s living national treasures, and it reflects many years of conservation work to protect this species, ” said His Excellency Eng Cheasan, Director General of Fisheries Administration of the Ministry of Agriculture, Forestry and Fisheries. “We will continue our efforts to ensure this iconic species recovers by eliminating all threats to the survival of Irrawaddy dolphins.”
While the new statistics provide a ray of hope, the dolphin’s future is threatened by the 11 proposed hydropower dams along the Mekong. One of these – the Xayaburi Dam in northern Laos – is almost complete, while construction on another mega dam on the Don Sahong channel in southern Laos is expected to begin before the end of the year by Malaysia’s Mega First Corporation Berhad.
These dams could also deal a crushing blow to the Mekong’s dolphins. The Don Sahong dam site is less than two kilometres upstream from a deep river pool, which contains Laos’ last four Irrawaddy dolphins. Blasting alone could seriously damage their sensitive hearing. Further downstream in Kratie, a much larger population of dolphins is also threatened by the dam that could drastically reduce its food supply.
The dams have the potential to irrevocably disrupt fish migration, which would endanger the world’s largest inland fishery and the main source of protein for the region’s 60 million people.

“The Don Sahong Dam is an ecological time bomb that threatens the food security of millions of people and a population of critically endangered Irrawaddy dolphins,” said Chhith. “The dam will have negative impacts on the entire Mekong River ecosystem all the way to the delta in Vietnam: it cannot proceed.”
“We urge the Laos government and the developer – Malaysia’s Mega First Corporation Berhad – to reconsider this ill-fated decision and wait until further studies on the environmental and social impacts have been conducted and all legal options and requirements under the Mekong Charter have been fully considered.”
The construction of the Don Sahong dam threatens a key population of the endangered Irrawaddy dolphin.
© Roland Seitre / WWF
Irrawaddy dolphins (Orcaella Brevirostris) at Koh Kon Sat, Mekong River, Cambodia.
© David Dove / WWF Greater Mekong