Deteriorating Mekong ecosystem alarms activists

Bangkok Post –

Environment advocates are voicing concerns over the Mekong River’s deteriorating ecosystem, especially with more projects set to affect the waterway in the pipeline.

“If these so-called development projects continue, especially the construction of more dams, the Mekong will face a crisis,” said Niwat Roi-kaeo, president of the Rak Chiang Khong Group, an environmental conservation collective based in Chiang Rai.

He was speaking at a seminar on the escalating problems facing the famous river.

Water in stretch of Thailand’s northeastern provinces has turned a greenish-blue colour, he said, adding that while this strange phenomenon makes the river look beautiful it could be a sign of danger.

The phenomenon is described by environmental experts as the “hungry water effect” where a river flow with excess capacity to transport sediment erodes the bed and banks.

Upstream dams trap the sediment eroded from rocks and soils, leaving the river starved of its sediment load. The potential energy of this “hungry water” scours the river banks downstream, uprooting trees or riparian vegetation and damaging bridges and other engineering structures, according to Mr Niwat.

Hungry water erodes river banks below a dam more severely than the usual tide, said Chawalit Witthayanant, an expert on fish in the Mekong River.

“During the first few years of this phenomenon, fish become unusually abundant in the river; but not long after the stocks dwindle rapidly”, he said.

Read more