Atlantic halibut is a premium flatfish with growing aquaculture production, particularly in Norway. Their slow growth, complex life cycle, and specialized needs create distinctive welfare challenges.
Atlantic halibut welfare in aquaculture faces challenges across their long production cycle. Hatchery mortality is high during the larval and early juvenile phase — feed transition from live prey to formulated diets causes significant losses, and eye migration failure affects a substantial proportion of hatchery fish. Their benthic lifestyle means high-density tank culture prevents natural resting behavior, causing chronic stress. Being large, powerful fish, halibut can injure themselves and tank infrastructure during handling. Slaughter of large halibut (40-80 kg fish) requires industrial-scale stunning equipment that is not uniformly deployed. Their slow growth means welfare costs accumulate over many years before harvest. The premium price point of halibut creates some incentive for higher welfare investment, as mortality is expensive, but welfare and mortality reduction are imperfectly correlated.