Turbot is a high-value flatfish farmed primarily in China, Spain, and Portugal, with welfare challenges related to its sedentary flatfish physiology and crowding in recirculating systems.
Farmed turbot present a different welfare profile from most farmed fish because of their benthic lifestyle — they rest flat on substrates rather than swimming in the water column. This creates interesting welfare dynamics: very high stocking densities in terms of kg/m3 may be less problematic for turbot than for pelagic species, because stacked fish can use vertical space. However, extreme crowding still causes aggressive interactions, scale damage, and hypoxia risk. Substrate provision — sand or fine gravel on tank bottoms — significantly improves welfare by allowing natural resting postures and reducing fin damage from bare concrete. Water quality is the dominant welfare determinant; ammonia and CO2 accumulation in poorly managed recirculating systems cause distress. Slaughter method varies widely, with live chilling still common despite evidence of prolonged consciousness.