Fish Pain Science: The Evidence for Analgesic Use in Aquaculture

Evidence that fish experience pain has accumulated significantly over two decades. This evidence base now supports analgesic use in aquaculture procedures as a welfare obligation.

Key Facts

Fish have nociceptors, opioid receptors, and ascending pain pathways
Morphine and lidocaine reduce avoidance behaviours and stress hormones in fish experiencing painful stimuli
The IASP now formally recognises fish as pain-capable animals
Procedures including tagging, biopsy, and handling cause measurable pain responses
Anaesthetics used in aquaculture include MS-222, clove oil, and carbon dioxide
Regulatory guidance on analgesic use in aquaculture remains poorly developed globally

Welfare Considerations

Fish pain science has moved beyond reasonable doubt. Fish experience noxious stimuli, learn to avoid pain-associated locations, and benefit from analgesic treatment in measurable ways. Aquaculture operations performing surgical procedures on fish without anaesthesia or analgesia cause documented suffering. The evidence base now supports mandatory pain management in aquaculture, but regulation has not caught up. Consumer and retailer pressure for welfare-conscious aquaculture must include pain management requirements.

What You Can Do

Support aquaculture certification schemes requiring anaesthesia for painful procedures
Advocate for fish pain management to be included in aquaculture welfare regulations
Learn about fish pain science to counter the misconception that fish do not feel pain