Public aquariums house millions of fish and other marine animals, raising questions about their welfare in captivity alongside their role in conservation education. Understanding this trade-off informs better aquarium practice.
Aquarium fish welfare spans a wide range depending on species, tank design, and management quality. Large pelagic species including whale sharks and great white sharks experience severe welfare compromise in any feasible captive environment, leading most institutions to end their display. Medium-sized reef fish can be maintained in welfare-positive conditions with adequate space, complexity, and conspecifics. Wild collection using cyanide causes both direct harm and broader reef damage. Captive breeding for display species represents a significant welfare improvement over wild collection. The educational conservation value of aquariums provides a rationale for captive holding but does not justify maintaining species whose needs cannot be met in captivity.