Public opinion and scientific evidence have driven major changes in how captive marine mammals are kept and displayed, with significant welfare implications for dolphins, belugas, and orcas.
Captive marine mammal welfare has been transformed by public scrutiny following high-profile campaigns against orca captivity. The welfare evidence for orcas specifically is stark: shortened lifespans, collapsed dorsal fins, stereotype frequency, stress-related health problems, and the extreme mismatch between tank dimensions and natural home ranges of hundreds of kilometres make the welfare costs of orca captivity very difficult to justify. Bottlenose dolphin welfare is more complex — some facilities provide enriched, large enclosures with trained staff who appear to have positive relationships with individual animals, while others maintain dolphins in cramped, barren tanks for entertainment shows that prioritise performance over natural behaviour. The trajectory toward sanctuary environments — seapens in natural water with larger volumes, natural temperature and salinity, and reduced performance requirements — represents a welfare improvement pathway for animals that cannot be released. For new facilities, the evidence increasingly does not support keeping large cetaceans in captivity for display purposes.