Laos to gain, Cambodia to suffer in Mekong hydropower projects: study

Laos will benefit from dam projects along tributaries of Mekong River but Cambodia will suffer most due to fish catch losses.

According to the Proceedings of the National Academy of Sciences, Laos will benefit with the Mekong dams from producing energy mostly for export to Thailand and Vietnam, but the repercussion would mostly be felt by Cambodia and partly by Vietnam due to losing a big percentage of their fish catch.

The said study warned that building hydropower dams along small branches of Mekong River could create catastrophic impacts on fish productivity and biodiversity.

"We find that the completion of 78 dams on tributaries, which have not previously been subject to strategic analysis, would have catastrophic impacts on fish productivity and biodiversity," said the Proceedings of the National Academy of Sciences.

Plenty of attention has focused on plans to develop 11 big dams along the main stem of the 4,600 kilometer Mekong River which passes through China, Myanmar, Laos, Thailand, Cambodia and Vietnam.

In December, ministers from Cambodia, Thailand, Vietnam and Laos postponed a decision on the first of those efforts -- the $3.8 billion Xayaburi dam -- saying more research was needed to assuage concerns from conservationists.

Since the area is home to many species of migratory fish, the analysis found that several dam projects could block more than 100 kinds of fish from swimming upstream, causing massive losses to diversity and fish supply.

Tens of millions of rural, poor residents in the region depend on subsistence fishing for their main source of protein, said scientists from Cambodia's Inland Fisheries Research and Development Institute and Stanford and Princeton University.

"We found there is going to be a very sharp tradeoff between producing energy and the impact on food and biodiversity," lead author Guy Ziv of Stanford University told AFP.

Ziv said researchers focused on 27 of the 78 planned tributary dams, because those 27 are scheduled for construction from 2015 to 2030 and their future remains up in the air.