Freshwater fish are among the most threatened vertebrate groups globally, with habitat degradation, pollution, and invasive species causing welfare harms to trillions of individual fish.
Freshwater fish welfare is a vast, largely unaddressed welfare challenge. The sentience evidence for fish now meets the threshold for serious moral consideration, yet the conditions experienced by wild freshwater fish — hypoxic pollution zones, dam barriers, temperature stress from warm water discharge — cause widespread suffering with essentially no regulatory protection. The scale is immense: trillions of freshwater fish inhabiting degraded ecosystems experience chronic physiological stress. Habitat restoration, dam removal, and pollution control serve both biodiversity conservation and individual fish welfare, demonstrating again how welfare and conservation goals align at the level of ecosystem protection.