Orca, dolphin, and other marine mammal captivity has declined significantly in public acceptance, as evidence of poor welfare and the inadequacy of captive environments has grown.
Large cetaceans are among the least suited animals to captivity. Their need for vast ranges, complex social structures, and rich acoustic environments cannot be replicated in any tank. Collapsed dorsal fins — nearly universal in captive orca males — indicate chronic stress. Stereotypic swimming patterns are analogous to zoo animal pacing. The welfare case against cetacean captivity is now overwhelming. Marine sanctuaries that allow semi-wild conditions are the most welfare-positive option for existing captive individuals.