The Mekong: River Under Threat

Abstract

The Mekong plays a vital role in the countries of the Lower Mekong Basin (LMB): Laos, Thailand, Cambodia and Vietnam. (Burma is not within the basin). Despite the environmental costs of China’s completed dams and the river clearances to aid navigation being limited so far, this will change once China has five dams in operation. And the costs exacted by those dams will be magnified if the proposed mainstream dams below China are built, particularly at Don Sahong and Sambor. In all four LMB countries the Mekong is a source of irrigation. In Vietnam’s Mekong Delta the annual pattern of flood and retreat insure that this region contributes over 50% of agriculture’s contribution to the country’s GDP. For all four LMB countries the Mekong and its associated systems, particularly Cambodia’s Great Lake (Tonle Sap), are a bountiful source of fish, with the annual value of the catch conservatively valued at US$2 billion. More than 70% of the Cambodian population’s annual animal protein comes from the river’s fish. Eighty per cent of the Mekong’s fish species are migratory, some travelling many hundreds of kilometres between spawning and reaching adulthood. Overall, eight out of 10 persons living in the LMB depend on the river for sustenance, either in terms of wild fish captured in the river or through both large and small-scale agriculture and horticulture.