Mortality of Walleyes and Saugers Caught in Live-Release Tournaments

摘要

We measured initial mortality (fish judged nonreleasable at weigh-in), prerelease mortality (fish judged nonreleasable 1-2 h after weigh-in), and postrelease mortality (fish that died during 5-d retention in net pens) in seven live-release walleye Sander vitreus tournaments conducted in April—October 2006 on four lakes and the Mississippi River. Among the seven events, initial mortality was 0-20%, prerelease mortality was 3-48%, and postrelease mortality was 0-100%. Mortality was generally low in events conducted when lake or river water temperature was below 18°C. Mortality was substantially higher in two events when water temperatures were above 25°C and in one event when fishing and postrelease mortality evaluation occurred in rough-water conditions. The relationship between water temperature and survival of walleye caught in live-release tournaments warrants further evaluation.