Delayed mortality and physiological stress responses in tournament-caught largemouth bass (Micropterus salmoides)

Largemouth bass (Micropterus salmoides) from 12 fishing tournaments during May 1988 through November 1989 (N = 457) were examined to evaluate delayed mortality and to characterize the physiological stress responses displayed by tournament-caught bass. Delayed mortality was highly significantly (P ≤ 0.01) related to the effects of water temperature and differing reservoirs. The effects of differing tournament organizations were also significant (P ≤ 0.05), but duration of live well confinement displayed no significant effects upon delayed mortality. Fish held in the live well for different periods of time displayed differences in plasma glucose levels which were near significance at the P ≤ 0.05 level. Fish held for longer than 4 hours seemed to display slightly lower glucose values than fish held less than 4 hours. Plasma cortisol concentrations were significantly (P ≤ 0.05) correlated with the relative weights of individual fish. No other significant physiological stress responses to tournament-related stressors were apparent as indicated by the blood plasma indicators of chloride, glucose, or cortisol concentrations.