Flatfish including plaice, Dover sole, and Atlantic halibut are caught in large quantities by demersal trawls and are increasingly farmed. Their welfare in both contexts is underappreciated.
Beam trawls — heavy steel frame nets dragged across the seafloor — capture flatfish but also destroy benthic habitat and crush non-target species. Flatfish experience the same barotrauma and prolonged suffocation as other trawled species. Their flat body shape makes them vulnerable to crushing under heavier catch in the net. In halibut aquaculture, metamorphosis from larvae to flatfish is a critical welfare period with high mortality. Adult farmed halibut require appropriate substrate and should not be kept in tanks that prevent natural benthic behaviour. Plaice and sole respond to noxious stimuli with avoidance behaviour consistent with pain experience.