Effects of current intensity and duration on the viability of microorganisms in natural seawater. The detection limit was 10 CFU/ml. Symbols: ♦, 1.55 mA; □, 10 mA; ▵, 50 mA; ○, 100 mA; ⋄, 500 mA; •, 1 A; ▪, 2 A. The inocula contained 1.0 × 103 cells/ml. The results shown are mean data from three experiments, and error bars indicate standard deviations.