One of the world’s largest inland fisheries is under threat from overfishing, dams and habitat fragmentation. The Tonlé Sap Lake in the Mekong River Basin now yields stable harvests of only very small fish species. Stakeholders, government and developers must put conservation and mitigation measures in place before it’s too late.
Hydropower construction is proliferating in the Lower Mekong Basin, disrupting natural seasonal river pulses and blocking the migration routes of riverine fishes. An estimated 60% of the catch in the Lower Mekong Basin is made up of migratory fish (G. Vaidyanathan Nature 478, 305–307; 2011). People who live along the Mekong River and on the floodplain will be particularly affected because the local fish they consume also rely on migratory riverine species for prey.
Without urgent action, the outlook is bleak for this once-sustainable fishery.
Nature 563, 184 (2018)