This report is the fisheries section of the Mekong River Commission Strategic Environmental Assessment of hydropower on the Mekong mainstream. Part one of this document provides a baseline assessment of Mekong fisheries providing information on biodiversity, capture fish production; aquaculture and risks related to dam development. Part two provides a fisheries impact assessment, describing likely changes as a result of dam building. Part three outlines avoidance and mitigation measures, before during and after dam construction.