Koi and ornamental fish are often treated as living decorations rather than sentient animals with welfare needs. Fish experience pain and stress, and their welfare in garden ponds and aquaria deserves serious consideration.
Fish welfare is underappreciated partly because fish are kept in environments where their behavioural signals are less readable than mammals. A koi gasping at the surface, flashing against pond walls, or isolating is in distress — but owners often miss these signs or attribute them to something other than welfare failure. The scale of ornamental fish keeping globally — hundreds of millions of fish — combined with frequently inadequate conditions makes this a significant animal welfare issue. Improving welfare requires better education at point of sale, clearer husbandry standards, and cultural recognition of fish as sentient animals.