Behaviour of walleye, Sander vitreus, and largemouth bass, Micropterus salmoides, exposed to different wave intensities and boat operating conditions during livewell confinement

Abstract

During live-release angling tournaments in North America, fish are typically retained in livewells onboard boats during the angling day. Mortality of fish occurs at some tournaments, and wave intensities and livewell conditions may influence mortality levels. This study used two species of fish targeted in live-release angling tournaments in North America (largemouth bass Micropterus salmoides L. and walleye Sander vitreus L.) to quantify the response(s) of fish in livewells to different wave treatments. Video analyses revealed that largemouth bass were active during low intensity disturbances, but during violent boat movements tended to settle to the bottom of the livewell and orient to face the direction of the disturbance. Walleye were less active than bass for all treatments, and additionally did not orient to face the direction of disturbance, consequently contacting the side of the livewell during boat rocking. These results are considered in the context of mortality at live-release tournaments.K E Y W O R D S : activity, behaviour, largemouth bass, livewell, tournament, videography, walleye.

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

“…Transported fish were found to have higher levels of plasma glucose and corticosteroids [9]. Corticosteroids are produced in response to exertion and stress, so elevated levels of these compounds is consistent with research that documents considerable energy expenditure by largemouth bass while avoiding collisions with other fish or livewell walls during transport [11]. Such collisions can result in dermal and ocular lesions, opening a vector for infections (a potential source of delayed mortality).…”

“…Stress levels can be influenced by a variety of factors including holding time *Address correspondence to this author at the Center for Earth and Environmental Science, SUNY Plattsburgh, USA; Tel: (860)859-7823; E-mail: galphonsemaynard@gmail.com [9], air exposure [10], livewell conditions [11], fish size [12], and water temperature [13]. Recovery time from physiological stress for a variety of fish species ranges from 8 to 12 hours, depending on post-release conditions [14].…”

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

“…Therefore, the documented relationship between survival of tournament-caught black bass and water temperature must be attributable to live-well confinement, handling during weigh-in, or both. 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.…”

Cognitive ability and sentience: Which aquatic animals should be protected?

“…Hooking and handling fish for release increases scale damage, making the fish more vulnerable to infection (Broadhurst & Barker 2000). Injury and mortality following the hooking of fish is common, especially where the hook penetrates deep into the tissues (Muonehke & Childress 1994), and the mortality increase is clear in live-release tournaments (Suski et al 2005). The actual process of capture on a hook leads to increased heart rate, cortisol production, and subsequent avoidance of the situation (Verheijen & Buwalda 1988, Pottinger 1998, Cooke & Philipp 2004.…”