Aquatic animals including fish, sharks, rays, and cephalopods in zoo and aquarium settings require specific welfare considerations related to water quality, space, and social needs.
Aquatic animal welfare in public aquariums encompasses an enormous range of species with vastly different welfare requirements, from tropical reef fish to large elasmobranchs and intelligent cephalopods. Water quality is fundamental — temperature, chemistry, and oxygen parameters outside species-specific tolerances impose constant physiological stress. Space requirements vary dramatically: small reef fish may be adequately housed in well-designed exhibits, while large pelagic species like whale sharks require enormous volumes that few facilities can provide. Cephalopod welfare — enrichment for octopuses, appropriate social conditions for cuttlefish — has received growing attention as their cognitive complexity has become better understood. The welfare quality of public aquariums varies enormously between institutions.