Pangasius (swai/basa) is one of the most exported farmed fish globally, produced at enormous volumes in Vietnam. Its welfare receives far less attention than its market share warrants.
Pangasius welfare represents a significant but largely invisible issue in global aquaculture. The species' ability to survive in low-oxygen conditions — breathing atmospheric air — means they tolerate conditions that would kill other fish, but physiological tolerance does not equal good welfare. At commercial stocking densities in Mekong delta ponds, pangasius cannot express normal behavioral repertoires. Water quality fluctuations — particularly ammonia spikes and dissolved oxygen crashes — cause stress responses even in this tolerant species. Harvest methods including pond draining and live transport in cramped conditions cause significant acute stress. The ASC pangasius standard has improved environmental sustainability but welfare-specific provisions are limited. Given the enormous production volume — billions of individual animals — even modest welfare improvements could affect a staggering number of fish.