Mortality of Anadromous Coastal Cutthroat Trout Caught with Artificial Lures and Natural Bait

Abstract

The mortality of anadromous coastal cutthroat trout Oncorhynchus clarki taken by anglers with worm-baited hooks of four different sizes, spinners with single hooks, spinners with treble hooks, and spinners with treble hooks baited with worms was investigated on the Stillaguamish and Snohomish rivers in Washington. In all but two comparisons mortality of cutthroat trout was greater (P < 0.05) from the four sizes of worm-baited hooks (39.5–58.1%) than from the three different spinner treatments (10.5–23.8%). The probability of killing fish was greater (P < 0.05) when fish were hooked in either the gill (95.5%), tongue (66.7%), esophagus (65.5%), or eye (53.8%) than in other anatomical locations. A group of untagged fish that were caught on worm-baited hooks but hooked only in the jaw or mouth were used as control fish to evaluate tagging mortality. The mortality of the untagged group (7.4%) was not greater than the mortality of fish caught on all terminal gear types and hooked in the upper or lower jaw (5.8%), suggesting that mortality from tagging was not an important factor. Mortality was positively related to bleeding at the time of hooking. Hooking a fish in a critical anatomical part was the most important factor causing subsequent mortality.