Pangasius (tra catfish) farming in Vietnam's Mekong Delta is one of the world's largest freshwater aquaculture industries, with welfare concerns around stocking density, water quality, and rapid growth under intensive conditions.
Pangasius farmed at high stocking densities in degraded water quality experience chronic stress from hypoxia, elevated ammonia, and competition. While pangasius can survive conditions that would kill other fish species, survival is not equivalent to welfare — animals experiencing chronic physiological stress from poor water quality are suffering even if not immediately dying. The scale of pangasius production means welfare improvements could benefit hundreds of millions of individual fish. The certification systems that exist for some Vietnamese pangasius provide a framework for welfare improvement, but uptake remains partial and market price pressure continues to incentivize cost-cutting that compromises welfare. Consumer choice of certified pangasius or plant-based alternatives creates market incentives for improvement.