Effects of Catch-and-Release Angling on Nesting Male Smallmouth Bass

Abstract

We assessed the effects of angling stress on nesting male smallmouth bass Micropterus dolomieu from two lakes in southeastern Ontario. In the first portion of the study, adult male smallmouth bass were hooked and then played either briefly (<20 s) or to exhaustion (2 min). White muscle acid–base and metabolite status were used as indicators of the extent of the physiological disturbance in these fish. Angling of smallmouth bass resulted in decreases in muscle pH and energy reserves for burst activity (phosphocreatine and adenosine triphosphate), as well as increases in muscle lactate, metabolic protons (▵H+), and partial pressure of carbon dioxide (Pco2). The physiological disturbance was most severe in smallmouth bass played to exhaustion. In the second portion of the study, other adult male smallmouth bass were hooked and played as described above. Fish played to exhaustion took four times longer to return to their nests than did fish played briefly. As a result, offspring in the nests of fish played to exhaustion were exposed to more predation risk. The physiological and behavioral effects of exhaustive exercise induced by angling indicate the potential for catch-and-release angling of smallmouth bass during their spawning season to negatively affect reproductive success.