The welfare of cetaceans in captivity is one of the most contested areas of animal welfare science, with evidence building against keeping large marine mammals in artificial environments.
The welfare evidence against keeping large cetaceans in captivity has grown substantially over the past two decades. Orcas - animals that range over 100km daily in the wild, live in complex matrilineal social groups, and demonstrate sophisticated cultural transmission - are particularly ill-suited to captive environments. Behavioral indicators including stereotypic swimming patterns, aggression toward trainers, and collapsed dorsal fins (a sign of chronic stress) indicate significant welfare compromise. The ethical position that captivity is justified by conservation education is increasingly difficult to defend given the limited conservation benefit evidence. Sanctuary sea pens - large marine enclosures in natural seawater - offer a welfare-positive alternative to release for cetaceans unable to survive independently.