Public aquariums house fish and marine invertebrates at a scale and with welfare implications that are rarely discussed. Understanding aquarium animal welfare helps evaluate these facilities.
Aquarium animal welfare encompasses a huge range of species with correspondingly diverse welfare needs. Pelagic species such as open-ocean sharks and rays that naturally travel thousands of kilometers fare particularly poorly in circular tank environments, often showing stereotypic circling behaviors. Coral reef fish with complex territories and social structures have specific space and social requirements. Large marine mammals including dolphins and whales present welfare challenges so significant that many jurisdictions have moved to ban their captive display. Fish welfare is the most overlooked area given the enormous numbers involved and the historical dismissal of fish sentience.