Turbot Welfare in Intensive Land-Based Tank Aquaculture

Turbot farmed in intensive land-based systems face specific welfare challenges from their flat benthic lifestyle in tank environments.

Key Facts

Turbot are the most valuable farmed flatfish in Europe with premium prices in high-end markets
They are farmed in land-based tanks in Spain, France, Portugal, and Scotland
As flatfish they require adequate flat bottom surface area for resting and feeding
Stacking of turbot directly on top of each other occurs at high stocking densities causing welfare problems
Recirculating aquaculture systems enable precise water quality control benefiting welfare

Welfare Considerations

Turbot welfare in intensive tank systems is directly affected by stocking density relative to tank bottom area. At very high densities turbot stack on top of each other, preventing lower fish from accessing food and causing physical injury. Feeding behaviour is impaired when fish cannot access the tank bottom. Stress from crowding reduces immune function. Their flat body shape and benthic lifestyle mean welfare assessment requires consideration of bottom area rather than water volume as for pelagic species. Modern recirculating systems with careful density management can provide good welfare outcomes.

What You Can Do

Support research into evidence-based stocking density limits for turbot based on bottom area
Choose turbot from farms with verified stocking density management protocols
Advocate for species-specific welfare standards for flatfish in aquaculture regulation
Encourage recirculating turbot farms to publish welfare monitoring data
Support development of validated turbot welfare indicators for use in assurance schemes