Catch and Release in Marine Recreational Fisheries

A Comparison of Circle Hook and Straight Hook Performance in Recreational Fisheries for Juvenile Atlantic Bluefin Tuna

G. B. Skomal, B. C. Chase, and E. D. Prince

doi: https://doi.org/10.47886/9781888569308.ch7

Abstract.—Catch quotas, bag limits, and minimum sizes have been the primary management tools to limit mortality in U.S. Atlantic bluefin tuna Thunnus thynnus fisheries. As a result of these regulations, increasing numbers of bluefin tuna are released annually by recreational and commercial fishermen. Post-release survival is highly dependent on the degree of physiological stress and physical trauma experienced by the fish. The type of terminal fishing tackle strongly influences hook location in the fish, as well as the degree of hook damage. This study compared the performance of circle hooks to straight hooks, relative to hooking location, damage, and catching success in natural bait fisheries for bluefin tuna that are practiced on the U.S. Atlantic coast. During the summers of 1997–1999, fishing trips were made offshore of Virginia and Massachusetts to catch juvenile bluefin tuna with comparable size circle hooks (sizes 10/0–12/0) and straight hooks (sizes 5/0–8/0), while drifting with natural bait. A total of 101 bluefin tuna was caught and dissected to quantify hooking location and to assess the extent of hooking damage. There was a significant association between hook type and hook location ( p < 0.05). Ninety-four percent of the bluefin tuna caught on circle hooks were hooked in the jaw, and four percent were hooked in the pharynx or esophagus. Fifty-two percent of the bluefin tuna caught on straight hooks were hooked in the jaw, and thirty-four percent were hooked in the pharynx or esophagus. Based on the observed hook damage, we estimated that release mortality would have occurred in four percent of the bluefin tuna caught on circle hooks and twentyeight percent caught on straight hooks. The ability of each hook type to hook and hold tuna was significantly different; however, overall catching success was similar. This comparison indicates that circle hooks cause less physical damage than straight hooks, while catching juvenile bluefin tuna, using natural baits and can be a valuable conservation tool in these recreational fisheries.