Freeze-Branding of flatfish: flounder, <i>Platichthys flesus</i>, and plaice, <i>Pleuronectes platessa</i>

The use of freeze-branding as a field-marking technique for flatfish is described. Similar recapture rates were obtained for flounders marked on the coloured, or eyed, side and for those marked on the white, or blind, side during the first two years after marking. Brands on adult flounders were still identifiable more than four years after release of the fish. The branding technique is also applicable to plaice.