As construction on the Don Sahong dam near the Cambodia-Laos border passes its halfway point, activists and locals are increasingly concerned over the disappearance of Irawaddy dolphins and incidences of illness they suspect are caused by the muddied water.
“The waters downstream in Cambodia have become opaque,” said Chum Hour, an environmental activist who went to visit the Don Sahong hydropower dam last week. “Before, we saw a few dolphins, but now they are gone.”
Mr. Hour’s trip, during which he took photographs showing that the dam is over halfway built, was inspired by recent remarks from Prime Minister Hun Sen saying the dam would have no impact “in terms of lack of water or fish migrations.”
Mr. Hour said the prime minister “should reconsider and intervene to delay the construction.”
Meach Mean, an environmental researcher, said Mr. Hour was right to be concerned, as the endangered dolphins—there are just over 70 left in the Mekong River—had migrated to the Laotian side of the border.
“The sound of the explosives disturbed the dolphins,” he explained, adding that the Laotian waters were not a conservation area, and illegal fishing there with gill nets, one of the main threats to the animals’ survival, was rampant.
Without the dolphins, tourist trips to the site have dropped, said Mr. Hour, disrupting an important source of revenue. Locals, meanwhile, said they were suffering from rashes caused by the clouded water, as well as unpredictable water flow.
“The water climbs and drops, climbs and drops,” said Sun Roth, chief of O’Svay commune in Stung Treng province’s Thala Barivat district, 4 km downstream from the dam site.
Of the fish that villagers have long relied on, he said: “We’ve lost a lot of them.”
Environment Minister Say Sam Al said the widely publicized remarks by Mr. Hun Sen did not capture his full view of the dam and its potential environmental impact.
“We’re working with Laos to conduct an assessment,” he said.