Changes in Blood Lactic Acid Concentrations in Alewives (Alosa pseudoharengus) During Passage Through a Pool and Weir Fishway

Blood lactic acid concentration of anadromous alewives (Alosa pseudoharengus) sampled during their upstream migration through a pool and weir fishway was not extremely high (46.7 mg/100 ml) and the degree of exercise exhibited during ascent was judged to be moderate. For fish that were subjected experimentally to severe exercise, the concentration (108.7 mg/100 ml) was more than five times that for rested fish (18.9 mg/100 ml). Of the three groups of fish sampled directly from the fishway pools, only one had an average concentration that differed significantly from that for the rested state.