the last breath of the Tonle Sap

Fisherman Piseth and his family live on the edge of the Tonle Sap Lake, where they are experiencing firsthand the accelerating consequences of climate change and the construction of hydroelectric dams along the Mekong. Fish stocks have collapsed, and with each passing season the family grows more uncertain about how they will continue to feed themselves and sustain their way of life.

For generations, the Tonle Sap represented an ideal home for Cambodian fishing communities. Its unique hydrological system—where the lake expands up to five times its size during the wet season as waters reverse from the Mekong—created one of the most productive freshwater ecosystems in the world, providing a reliable source of food and income for millions.

Today, that fragile balance is unraveling. Climate change, combined with intensive dam development upstream on the Mekong, is fundamentally reshaping the Tonle Sap ecosystem, threatening a cornerstone of Cambodia’s food security and cultural heritage.

According to the Mekong River Commission, 2020 recorded the lowest flow levels of the Tonle Sap River since 1997. That year, the river failed to fully reverse its flow, a critical process for replenishing the lake’s fisheries—placing the livelihoods of fishing families like Piseth’s in jeopardy.