Dover Sole Welfare in Flatfish Aquaculture

Dover sole is a high-value flatfish farmed in Europe, but its specific behavioural needs make welfare provision challenging in intensive systems.

Key Facts

Dover sole are benthic ambush predators that require substrate contact and cover — open-water tank environments cause chronic stress
They have slower growth rates than turbot and seabream, making them expensive to produce but highly valued
Cannibalism and aggression are significant welfare and production problems at high stocking densities
Sole have complex feeding behaviours and often refuse formulated diets initially, causing welfare problems during weaning

Welfare Considerations

Dover sole welfare is compromised by standard recirculating aquaculture system (RAS) tank designs that offer bare concrete or smooth plastic floors without substrate. In nature, sole bury themselves in sediment for camouflage and predator avoidance — deprivation of this behaviour causes chronic stress responses. Incorporating sand or fine gravel substrates into tank design substantially reduces cortisol levels. Aggression-related injuries around the head and mouth are common in high-density systems.

What You Can Do

Provide sand or fine substrate in tank bottoms to allow burying behaviour
Reduce stocking density below recommended maximums to minimise aggression
Implement careful diet transition protocols to reduce weaning stress
Monitor injury rates and remove injured fish promptly to prevent secondary infection