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Luang Prabang in Laos — a city chock-a-block with gilded Buddhist temples — sits at the confluence of the Nam Khan and Mekong rivers. At all hours of the day, people can be found dotted along the shallows, standing in the water and catching fish with hand-held nets. This type of subsistence fishing supports about 60 million people living along the 4,350 kilometres of the mighty Mekong — but maybe not for long. Laos and other countries — China, Myanmar, Cambodia, Thailand and Vietnam — are on a dam-building spree, which will reduce the water flow in the Mekong and prevent the passage of fish, threatening the livelihoods of these subsistence fishers, diminishing biodiversity and flooding cultural sites.