Physiological changes in trout (Salmo gairdneri) during a short-term exposure to resin acids and during recovery.

Six rainbow trouts were exposed to a 2 mg/l concentration of resin acids for 24 h. The toxicants influenced respiration by causing a decrease in arterial P02, red cell volume and pH, and an increase in ATP/Hb ratio. These responses were reversible on recovery. A disturbance in hydromineral balance was shown by a decrease in plasma chloride concentration, which was reversible in all but one fish. This fish had additional metabolic difficulties as shown by increases in plasma lactate concentration and enzyme activity. An indication of liver dysfunction was the increase in plasma bilirubin concentration, continuing throughout recovery.