The Don Sahong dam Laos plans to build on the Mekong River could kill off the last of the Irrawaddy dolphins on the waterway, the World Wide Fund for Nature (WWF) warned Thursday.
The already critically endangered population of dolphins living on a 190-kilometer (118-mile) stretch of the Mekong mainstream between southern Laos and northeast Cambodia will be further threatened by the dam construction work and changes in habitat it causes, the conservation group said.
The WWF called for a suspension of the 260-megawatt dam, urging Cambodia’s Prime Minister Hun Sen to request a moratorium on the hydropower project when regional leaders meet for a summit on Mekong River development in April.
“Plans to construct the Don Sahong dam in a channel immediately upstream from these dolphins will likely hasten their disappearance from the Mekong,” WWF-Cambodia’s country director Chhith Sam Ath said.
“The dam’s impacts on the dolphins probably cannot be mitigated, and certainly not through the limited and vague plans outlined in the project’s environmental impact assessment.”
The WWF estimates that only 85 Irrawaddy dolphins remain on the Mekong. The Don Sahong project in southern Laos is located just one kilometer (about half a mile) upstream of the core habitat for the dolphins.
The aquatic mammals are already reeling from a low calf survival rate and are threatened by entanglement in fishing nets and subsequent drowning, according to the group.
Explosives that dam builders intend to use to excavate millions of tonnes of rocks in the area will create strong sound waves that could kill the dolphins, the WWF said.
Increased boat traffic, changes in water quality, and habitat degradation from the dam will also pose direct risks to the population, it said.
Most of the zone on the Mekong where the dolphins lives has been declared a protective area by Cambodia, which has banned hunting the animals and relies on them for tourism.
Call for suspension
WWF said it was calling for suspension of the dam project, which is slated to begin construction soon and be completed in 2018, to “allow decisions to be reached using sound science and in consultation with impacted countries.”
The WWF and other environmental groups have raised concerns that the dam will block a key fish migration channel and pose a regional security threat for the some 60 million people in the region who rely on fish and other products from the river for their nutrition and livelihoods.
Laos’s announcement in September 2013 of plans to build the dam prompted objections from neighboring Thailand, Cambodia, and Vietnam, which said not enough study had been done on the impact of the project’s downstream impact.
WWF urged Laos to consider other alternatives to the dam, such as the Thakho project proposed on a nearby tributary, which it said would have “far less impact” on the Mekong.
“It is not too late to suspend the Don Sahong project and consider smarter alternatives,” WWF-Cambodia’s technical director Gerry Ryan said.
“Not building the Don Sahong dam is not an irreparable blow to the development aspirations of Laos, or their ability to produce electricity, but building it will almost certainly cause the extirpation of their dolphins and threaten critical fisheries,” he said.