The keeping of dolphins, orcas, and other cetaceans in captive facilities is among the most controversial practices in the zoo and aquarium world, with scientific evidence strongly suggesting inadequate welfare in standard facilities.
Cetacean captivity welfare evidence has accumulated substantially over decades and points consistently toward fundamental incompatibility between the space, acoustic, social, and cognitive needs of cetaceans and the conditions of even the largest and best-funded aquarium facilities. The extremely restricted ranging, abnormal acoustic environment (concrete pools are acoustically chaotic for echolocating animals), forced proximity to incompatible conspecifics, and absence of natural foraging behavior create chronic welfare compromise. The welfare of orcas in captivity is particularly well-documented, with higher rates of aggression toward trainers, stereotypic behaviors, and dental pathology than any wild population. Several countries have banned or are phasing out cetacean captivity, and retirement to coastal sea pen sanctuaries is being actively developed as an alternative.