Diseases of fish in the Ringhals-Vaeroe area 1987

This report presents the results of an investigation of external fish diseases in the Ringhals-Vaeroe area at the Swedish west coast. The investigation were concentrated upon cod, Gadus morhua, and dab, Limanda limanda, which were the two main demersal fish species in the area. A total number of 10 different disease symptoms were registrated in cod and dab. Only one of the registrated symptoms, platyspondyli (vertebral compresion) were found with an increased frequency, 8%. In earlier investigations at the west coast only 0,1% of the cod has been found with this disease. The cause of this high frequency is unknown. (authors)