Cambodian experts on Thursday expressed concerns over the Laos Don Sahong dam development project, saying the proposed hydroelectric dam would pose a serious threat to the existence of the biodiversity on the Mekong River in Cambodia.

Some 90 conservationists, environmentalists, development partners, academia, fishery scientists, and local and international non-governmental organization representatives met here to discuss the concerns, said a joint press statement from The NGO Forum on Cambodia and the River Coalition in Cambodia, which organized the forum.

The meeting came after a field visit at Don Sahong dam site last week.

"The civil society organization representatives working on rivers and livelihood issues have seen the huge negative impacts of the dam development on the Mekong biodiversity such as rarely dolphin species and fishery resources vital to the hundreds of thousands of people in Cambodia and Vietnam," the statement said.

The proposed 260-megawatt Don Sahong dam is one of 12 hydropower projects currently being studied and proposed for construction on the lower Mekong River after Xayaburi dam, Tek Vannara, executive director of The NGO Forum on Cambodia, said, adding that it is located 2 km from the Lao-Cambodia border in southern Champasak province.

"If the dam built, it will block the Hou Sahong channel, one of the main channels on the Mekong River about 2 km upstream of the Lao-Cambodia border," he said. "To date, there has been no genuine effort to meaningfully consult Cambodian government authorities or affected communities downstream in Cambodia."

Last month, the World Wildlife Fund (WWF) warned that the proposed Don Sahong hydroelectric dam could threaten the existence of critically endangered Irrawaddy dolphins in downstream Cambodia, saying that the dam is located just 2 km upstream of the core habitat for Mekong dolphins.

The WWF urged Cambodian Prime Minister Hun Sen to call for a moratorium on the dam during the Mekong River Commission's Heads of State Summit in April.

Freshwater Irrawaddy dolphins are critically endangered in the Mekong River, where their numbers have dwindled to around 85 individuals restricted to a 190 km stretch of the Mekong River mainstream between southern Laos and northeast Cambodia, the WWF said.