Fish is vital to the well-being and livelihoods to millions of people in the Lower Mekong Basin, many of whom are poor, relying on fish as a major source of animal protein, sometimes the only source. The supply of ‘free’ wild fish is under threat from overfishing, climate change, habitat modification and hydro power development which could mean less fish supplied from natural sources yet at the same time more demand. Aquaculture - farming of fish and other aquatic animals - is becoming increasingly more important in supplying fish to people in the region. This study was initiated to explore in more detail future fish supply scenarios, the role of aquaculture, and provide a basis for understanding future investment and strategies for its sustainable development. The study was conducted by the Fisheries Administration (FiA), Inland Fisheries Research Development Institute (IFReDI) and the WorldFish Center co-funded by Australian Centre for International Agricultural Research (ACIAR), and the Ministry of Foreign Affairs, Japan.