Rainbow trout mortality began to increase for the high NO3-N treatment only 1-week after treatments were initiated (Fig. 3).Thereafter, cumulative survival was consistently lower for the highNO3-N treatment for the remainder of the study (Fig. 3). Over the final 2–3 weeks of the study rainbow trout mortality increased for both groups but was more severe within the high NO3-N treat-ment (Fig. 3). At the conclusion of the study, cumulative rainbowFig