The welfare of cetaceans and other marine mammals in captivity has become a major public controversy following evidence that captive environments cause chronic psychological and physical harm.
The captivity of cetaceans, particularly killer whales and dolphins, presents perhaps the clearest example of species that cannot have their welfare adequately met in commercial captive environments. Their intelligence, social complexity, acoustic communication, and requirement for vast oceanic ranges create a mismatch with tank environments that behavioral evidence consistently confirms causes chronic welfare harm. The documentary Blackfish brought public attention to what welfare scientists had documented for decades. Transitioning existing captive cetaceans to sea pens while ending breeding programs represents the most humane pathway forward for animals that cannot be released to the wild.