Atlantic halibut farming is growing in Norway and Scotland, and the unique biology and behavior of these large flatfish creates specific welfare challenges in intensive aquaculture.
Halibut welfare illustrates how species biology interacts with production systems to create specific welfare challenges. As bottom-dwelling flatfish, halibut have evolved to rest on substrate; tanks without resting areas force them into unnatural postures, causing stress and exhaustion. The metamorphic period is particularly welfare-sensitive: environmental disruption during eye migration causes physical deformities that compromise both welfare and productivity. Aggression management is challenging in species that are naturally solitary predators; density management and structural complexity to allow separation can reduce injury rates. The growing commercial importance of halibut creates economic incentives to optimize production that must be balanced with welfare standards informed by the specific biology of this unusual and poorly understood species.