Physiological and Behavioral Stress Responses of Walleyes Transported in Salt and Buffered-Salt Solutions

Abstract To evaluate the value of transporting fingerling walleyes Stizostedion vitreum in buffered sodium chloride, we monitored blood chemistry, behavior, and water quality in conjunction with two 5-h transport trips. The control salt mixture was 0.50% sodium chloride (NaCl), and the buffered treatment was 0.45% NaCl and 0.05% sodium bicarbonate (NaHCO3). We also collected posthaul blood samples from walleyes 2 h after they were placed into cages in East Okoboji Lake, as well as daily during a 72-h recovery period in hatchery raceways. Behavior was tested before and after hauls to quantify any disorientation that might occur as a result of hauling procedures. The addition of NaHCO3 to haulingtank water significantly increased the pH and alkalinity of the water compared with the unbuffered control. Overall, buffering produced significant effects on water chemistry but only minor effects on physiological measures of stress and the acid–base balance. In part, the effects of ram-air ventilation in removing ...