Harold L. Schramm Jr.
Bruce C. Vondracek
Patrick D. Gerard
Christopher J. Chizinski
John H. Loomis
2013
<p><span>We examined the effects of acclimation water temperature,live‐well (LW) water temperature,and LW dissolved oxygen (DO) concentration on survival of adult Walleyes </span><i>Sander vitreus</i><span> subjected to simulated tournament conditions (angling,LW confinement,and weigh‐in procedures) under controlled laboratory conditions. We tested three acclimation temperatures (12,18,and 24°C),and three LW temperature differentials (Δ</span><i>T</i><span> = −4,0,and +4°C) were tested at each acclimation temperature. Survival was monitored after 8 h of LW confinement and during a 5‐d retention period in 1,700‐L tanks. None of the Walleyes that were acclimated to 24°C and subjected to simulated tournament procedures survived the 5‐d retention period; for fish subjected only to simulated angling at 24°C,survival during the 5‐d retention period was 29%. Five‐day survival was generally over 70% at acclimation temperatures of 12°C and 18°C,and we observed a significant interaction between acclimation temperature and Δ</span><i>T</i><span>; survival was greatest in LWs at −4°C Δ</span><i>T</i><span> for fish acclimated to 18°C and in LWs at +4°C Δ</span><i>T</i><span> for fish acclimated to 12°C. Best survival of Walleyes subjected to the stress of angling and tournament procedures was obtained at temperatures 6–8°C below the optimum temperature for adult Walleyes (i.e.,optimum = 20–22°C). Five‐day survival exceeded 70% when LW DO was 5 or 12–15 mg/L (at an acclimation and LW temperature of 18°C),but survival was 0% when DO was 2 mg/L. Anglers may increase survival of Walleyes through careful manipulation of LW temperature and DO when ambient temperature is at or below 18°C,but high mortality of angled and LW‐retained Walleyes should be expected when ambient water temperatures are 24°C or greater.</span></p>
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10.1080/00028487.2013.785979
en
American Fisheries Society
Effects of simulated angler capture and live-release tournaments on walleye survival
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