Susceptibility of the brine shrimp Artemia and its pathogen Vibrio parahaemolyticus to chlorine dioxide in contaminated sea-water

Adults and nauplii of the brine shrimp, Artemia , together with Vibrio parahaemolyticus , were placed in sewage-contaminated sea-water which had been treated with chlorine dioxide (Hallox E-100^TM) to test its potential as a disinfectant for salt water aquaculture. The nauplii were very susceptible to low concentrations of chlorine dioxide (47 μg/1 Cl^-), but the adults were slightly more resistant. Sterile sea-water treated with lower concentrations of chlorine dioxide (less than 47 μg/1 Cl^-) had no effect on the shrimp, but inhibited the growth of V. parahaemolyticus. In sewage-contaminated sea-water, chlorine dioxide levels of 285–2850 μg/1, necessary for the inactivation of V. parahaemolyticus and any native bacteria, destroyed the Artemia culture. Hallox E-100^TH persisted in sea-water for 18 h, but later decayed. We conclude that: (i) Artemia nauplii are a sensitive and convenient test-organism to determine low concentrations of chlorine dioxide in sea-water; (ii) chlorine dioxide is efficient for controlling V. parahaemolyticus in sea-water; and (iii) chlorine dioxide should be further evaluated as a potential disinfectant for aquaculture, but, for higher organisms than Artemia.