Physiological Significance of the Weigh-In during Live-Release Angling Tournaments for Largemouth Bass

Abstract

Abstract.-In the current study, we simulated different components of a live-release angling tournament (angling, live-well confinement, and weigh-in) to determine the relative physiological significance of these tournament components for largemouth bass Micropterus salmoides. Our results indicated that depletions of white muscle energy stores and accumulations of muscle lactate (i.e., a large metabolic disturbance) are the most important consequences of live-release angling tournaments for largemouth bass. This study also showed that there are two distinct components of a live-release tournament that cause a metabolic disturbance in largemouth bass: angling and the weigh-in. While the physiological consequences of angling are already well understood, this is the first study to show that the weigh-in portion of a live-release tournament also causes a large anaerobic disturbance in largemouth bass. In our simulation, the weigh-in resulted in a 75% decrease in white muscle phosphocreatine, a 46% decrease in ATP, and a 62% decrease in glycogen relative to control largemouth bass. The weigh-in simulation also caused the lactate concentration in white muscle to increase by about sevenfold relative to control fish and resulted in significant changes to cardiac function. Based on these results, subsequent experiments were performed to determine the main factor(s) responsible for the metabolic disturbance that results from the weighin. These experiments demonstrated that the period of air exposure during the weigh-in was a major cause of this disturbance. We recommend that tournament organizers minimize the air exposure that largemouth bass receive during the weigh-in to improve the physiological condition of released tournament-caught fish.

Effectiveness of Livewell Additives on Largemouth Bass Survival

“…Largemouth bass may recover from capture, handling, and livewell confinement stress if water quality is good (Furimsky et al 2003;Suski et al 2004), regardless of livewell additives. Although we did not find significant differences in delayed mortality among the livewell treatments, the consistent trend of higher mortality with livewell treatments during the field experiments suggests that additives may impart additional negative stressors that increase mortality.…”

“…Because the rate of competitive angling events continues to increase (Kerr and Kamke 2003;Schramm and Hunt 2007), interest in minimizing mortality is an issue of concern among anglers and fisheries biologists alike (Schramm and Hunt 2007;Siepker et al 2007). Acting on these interests, researchers have examined the effects that fish size (Meals and Miranda 1994;Weathers and Newman 1997;Neal and Lopez-Clayton 2001), water temperatures (Schramm et al 1987;Meals and Miranda 1994;Neal and Lopez-Clayton 2001), various tournament procedures (Weathers and Newman 1997;Suski et al 2004), and livewell conditions (Carmichael et al 1984;Plumb et al 1988;Cooke et al 2002;Gilliland 2002;Suski et al 2004) have on black bass survival rates after competitive angling events. Indeed, black bass mortality associated with these events can be relatively low (0-28%), whereas other events result in mortality rates as high as 98% (Champeau and Denson 1988;Lee et al 1993;Wilde 1998;Neal and Lopez-Clayton 2001;Gilliland 2002;Wilde et al 2002;Edwards et al 2004;Siepker et al 2007).…”

A Simple Model for Predicting Survival of Angler‐Caught and Released Largemouth Bass

“…Livewell confinement might subject fish to stressors such as deficient dissolved oxygen, accumulated metabolic wastes, crowding, and elevated rates of activity (Hartley and Moring 1993;Kwak and Henry 1995;Cooke et al 2002;Suski et al 2005). In addition, air exposure during conventional weigh-in has been 838 WILDE AND POPE identified as a main cause of physiological disturbance in largemouth bass and walleyes Sander vitreus (Suski et al 2004;Killen et al 2006), and there is evidence that the degree of the physiological disturbance in largemouth bass is related to air temperature.…”

Use of external Indicators to Evaluate Stress of Largemouth (Micropterus salmoides) and Smallmouth (M. dolomieu) Bass at Tournaments

“…Tournament-captured fish are likely to have high levels of plasma lactate due to intense exertion [29,33,34]. In these studies, aspartate aminotransferase (AST) and other blood chemistry indicators of stress were highest among fish with severe barotrauma.…”