Atlantic halibut are among the most challenging and welfare-intensive fish to farm, with slow growth, specific environmental requirements, and complex early life needs.
Atlantic halibut welfare presents unique challenges across their life cycle. The metamorphic stage — when juveniles transform from symmetric to asymmetric form — is a period of significant physiological vulnerability. Juveniles that fail to properly metamorphose (remaining symmetric) suffer chronic welfare compromise and are typically culled. Halibut are sensitive to crowding and light — they require appropriate bottom substrate and light management for normal behavior. Their long production period means they accumulate welfare costs over years if conditions are suboptimal. Handling stress is particularly severe — cortisol responses to capture and air exposure are extreme. Despite these challenges, Atlantic halibut farming is expanding due to high market value. Welfare standards need to keep pace with production growth.