Atlantic halibut farming is a growing sector with distinctive welfare challenges related to the species behavioral and physiological characteristics as a large flatfish.
Farmed halibut present welfare challenges that differ significantly from salmon and trout aquaculture due to the species flatfish biology and behavioral characteristics. The metamorphic development of halibut — in which one eye migrates across the skull during early development — is sensitive to environmental conditions, and failures of this process create permanently malformed animals with compromised ability to feed and swim throughout their lives. A welfare-oriented hatchery operation would monitor malformation rates as a key welfare indicator and adjust larval rearing conditions to minimize their occurrence. The cannibalistic tendencies of halibut require careful stocking density management and frequent size grading — both of which cause handling stress that must be minimized through careful technique. Pre-slaughter stunning, while not universal, is achievable and should be standard practice in welfare-certified halibut production.