Skin lesions in fish: causes and solutions

Introduction In recent years, the welfare of fish has received increasing attention and attempts have been made to control welfare in farmed fish. This may be achieved through regulation of management practices, including stocking density, etc. Skin lesions in farmed fish are an important challenge to the fish farmer. Fish with ulcers, fin erosions or impaired eyes are very conspicuous among the healthy fish swimming around in the tank or net pen. If only few fish are affected it is not an economical problem, but the welfare of these fish are not taken care of in an acceptable manner. Despite giving the fish the best environmental conditions, gentle handling or an adequate treatment if necessary, some members of such large populations will suffer because of skin lesions. To get these individuals out of the production may be a great challenge.