Controlled waterborne exposures of Pacific herring (Clupea pallasii) to Vibrio anguillarum and V. ordalii failed to result in overt signs of disease or mortality from vibriosis. Cumulative mortalities among Vibrio - exposed Pacific herring (3.3 - 5.0 percent) were similar to those of saline-exposed negative controls (10 percent) and significantly less (P less than 0.001) than those of Vibrio - exp