Fish in public aquariums and zoos represent an enormous but poorly regulated welfare challenge requiring species-specific approaches.
The welfare of fish in public aquariums is an emerging concern as the evidence for fish sentience strengthens. Large pelagic species like sharks and rays show obvious behavioral abnormalities in typical aquarium conditions. Even smaller species in community tanks can experience chronic stress from inadequate space, incompatible species mixing, and inability to express natural behaviors like territory establishment and schooling. Aquarium welfare standards have largely focused on water quality without addressing behavioral needs.