Abstract
The cidal effects of ultraviolet (U.V.) irradiation on fish pathogenic viruses were examined. Basic experiments were carried out to determine the usefulness of a U.V.-water treatment unit for the disinfection of IHNV and OMV.
The results obtained are summarized as follows:
1. The disinfectant effect of U.V. on 6 species of 7 strains of cell free fish pathogenic viruses was examined. IHNV, OMV, CCV and H. salmonis were found to be sensitive to U.V. and the 99% or more reduction of their infectivity (ID99)was measured to 1.0-3.0×103μW·sec/cm2. Susceptibility of IPNV and CSV was found to be low and the ID99 was measured to 1.0-1.5 × 105μW·sec/cm2.
2. U.V. treatment of less than 16.7l/min flow rate that is equivalent to more than 7.6×104μW·sec/cm2 U.V. dosage, is an effective means of disinfecting the 100 TCID50/ml of IHNV and OMV suspended in dechrolinated city water.
