Atlantic halibut is one of the world's most valuable farmed fish, but its unusual physiology and behaviour create distinctive welfare challenges in aquaculture systems designed primarily for salmonids.
Halibut welfare presents unique challenges because standard aquaculture infrastructure — cylindrical tanks, current-based swimming systems — is poorly suited to a benthic flatfish. Best-practice halibut facilities use shallow raceway systems with large bottom surface area, low stocking densities calculated on floor area rather than volume, and careful light management to reduce cataract formation. The prevalence of cataracts in farmed halibut — a directly preventable condition linked to nutrition and light exposure — is a welfare indicator that demands systematic attention. Halibut also show significant stress responses to crowding during harvest; pre-harvest fasting protocols and crowding minimisation reduce acute welfare impacts. The high value of farmed halibut provides economic incentive for welfare investment that does not exist for lower-value species.