Study: CBD Reduces Stress-Related Behaviors in Ornamental Fish During Transport

The research was conducted by scientists from the University of the West of Scotland, the University of Strathclyde, and the Waltham Petcare Science Institute. The study focused on the ornamental fish supply chain, which often involves multiple transport stages that are known to induce stress and compromise animal welfare. Researchers examined whether CBD, a compound with documented anxiolytic and anti-inflammatory effects in mammals, could help mitigate these stress responses when added to transport water.

In the first phase of the experiment, groups of variatus platy fish were transported for 30 minutes in sealed bags containing either plain water, a solvent control, or one of three CBD concentrations. After transport, the fish were observed as a group immediately, 30 minutes later, and again after two hours. Researchers measured behaviors commonly associated with stress, including biting, chasing, erratic swimming, and immobility. The mid-range CBD concentration was identified as the lowest dose that consistently reduced stress-related behaviors.

That concentration was then used in a follow-up experiment examining individual fish behavior and physiology after transport. Fish exposed to CBD traveled shorter distances, moved more calmly, and spent less time displaying stress-linked immobility compared with control groups. While CBD did not affect water cortisol levels or skin mucus production, behavioral indicators of stress were clearly reduced.

The findings suggest CBD could be incorporated into commercial water conditioners as a practical way to improve welfare during ornamental fish transport.