Halibut aquaculture is a growing industry, but the welfare needs of this distinctive flatfish are poorly understood and often inadequately met in commercial settings.
Halibut are unusual flatfish that lie on the seabed and have distinctive sensory needs. In intensive aquaculture, overcrowding causes skin abrasions, fin damage, and stress-related immunosuppression. Eye abnormalities are common in farmed halibut, linked to inadequate early-life conditions during metamorphosis. Water quality, stocking density, substrate provision, and appropriate light cycles all affect welfare. Because halibut grow slowly and require years to reach market weight, prolonged poor welfare conditions can cause significant cumulative suffering. Industry welfare standards for halibut lag behind those developed for salmon, despite comparable sentience evidence.