For decades, Nov Lun and his fellow fishermen harvested the rich bounty of the Sesan River in northeastern Cambodia. Then, three years ago, a giant hydroelectric power plant opened upstream from his village of Kumpun. Irregular water releases from the dam began regularly entangling his nets and dislocating his fishing boat. Fish started disappearing, and soon most of his livelihood had washed away. “The river has changed a lot,” says the 70-year-old Lun.