Euthanasia of injured, sick, or surplus aquatic animals requires species-specific methods — and many commonly used approaches are inhumane by current welfare standards.
Aquatic animal euthanasia is one of the most welfare-neglected areas of animal husbandry. Aquaculture workers routinely use methods that are inhumane by mammalian standards — putting fish in ice water, using CO2 at high concentrations, or simply removing them from water. The welfare case for adopting validated, humane methods is the same as for any other species: minimising suffering at the end of life is a welfare obligation. Species-specific guidance from organisations like the AVMA and UFAW provides evidence-based protocols for fish, crustaceans, and other aquatic species.