Pangasius (basa or swai catfish) are farmed extensively in the Mekong Delta under conditions that raise significant welfare and environmental concerns.
Pangasius welfare in intensive cage culture is severely compromised by extraordinary stocking densities that prevent normal swimming behavior and create chronic crowding stress. While pangasius tolerate poor water quality better than salmon or trout, tolerance does not mean welfare is adequate — stressed fish show measurable physiological and behavioral responses even when they survive. Slaughter is typically by asphyxiation or live evisceration without prior stunning, causing prolonged suffering. Environmental pollution from pangasius pond discharge also affects wild fish in the Mekong Delta. Third-party certification exists (ASC pangasius standard) but covers only a minority of production, and its welfare components are limited.