Stocking density-dependent growth of Dover sole (Solea solea)

Dover sole were reared at 6 different stocking densities between 0.56 and 12.6 kg/m2 with duplicate tanks for each treatment. The experiment lasted for 55 days. Water quality effects on growth were minimised by making the flow rate per tank proportional to the feeding load. Individual initial and final weights were determined for all fishes to calculate the specific growth rate and the coefficient of variation within each culture tank. The specific growth rate of Dover sole significantly decreased with increasing stocking density. Mortality increased significantly with increasing stocking density. The difference between initial and final CV (ΔCV) increased with stocking density (P < 0.06). A significant relation between stocking density and productivity was found. Productivity peaked at a stocking density of 7.4 kg/m2. The underlying mechanisms causing reduced average individual growth with increasing stocking densities are still poorly understood. Therefore, systematic behavioural studies focusing on the mechanisms causing depressed growth with increasing stocking density are recommended for future research.