"CHIANG KHONG, Thailand - From February to April each year, Kam Thon spends most of her days knee-deep in the waters of the Mekong River by her village in northern Thailand, gathering river weed to sell and cook at home.
Kam Thon and other women who live by the Mekong have been collecting river weed, or khai, for decades, but their harvest has fallen since China built nearly a dozen dams upstream.
The dams have altered the flow of water and block much of the sediment that is vital for khai and rice cultivation, researchers say.
"Generally, the water is clear and the level is lower in the dry season, and we can easily wade in and harvest khai. But now, the water level is higher during dry season, which makes it more difficult," said Kam Thon, who sells khai at the local market."
Rina Chandran reports for Thomson Reuters Foundation March 21, 2023.
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