Atlantic halibut is among the slowest-growing farmed fish species, spending years in aquaculture conditions. Welfare management across this extended production period is critical.
Atlantic halibut welfare presents unique challenges arising from the extended production period and their distinctive flatfish biology. The 4-7 year production cycle means that any welfare compromise — whether from suboptimal stocking density, poor water quality, or inadequate feeding — affects individual fish for a substantially longer period than for salmonid species. Lighting management during the juvenile phase is critical — photophobic juveniles exposed to excessive light show stress responses and abnormal behavior. The transition from symmetric larva to asymmetric flatfish requires careful management as this developmental period involves significant physiological change. Slaughter welfare research is less developed for halibut than for salmonids, and developing validated percussive or electrical stunning protocols for this species is an important welfare research priority.