The keeping of dolphins, orcas, and other cetaceans in captivity for entertainment has declined significantly following public awareness campaigns, but remains active in many countries.
Marine mammal captivity welfare evidence is perhaps the strongest and best-documented welfare case against any animal entertainment sector. Orcas in captivity show collapsed dorsal fins (indicating chronic stress or circulatory problems), significantly shortened lifespans, and high rates of aggression to both trainers and tank companions. Dolphins show stereotypic behavior and require ongoing medication for stress-related conditions. The cognitive complexity, social structures, and movement needs of cetaceans cannot be met in any tank. The public shift away from captive cetacean entertainment following documentaries and campaigns has been one of the most rapid industry welfare changes in history.