Marine mammals in aquariums and marine parks face particular welfare challenges — their space requirements, acoustic needs, and social complexity cannot be fully met in captivity.
The welfare of large cetaceans in captivity is fundamentally compromised by the impossibility of meeting their spatial, acoustic, and social needs at any commercial scale. Orcas and dolphins in tanks show collapsed dorsal fins, stereotypic circling, aggression, and high mortality. Smaller species in well-managed aquariums can achieve better welfare outcomes, but marine mammal captivity for entertainment remains ethically contested.