Recreational fishing is popular throughout the world and has significant socioeconomic impacts. Catch-and-release fishing is beneficial for a number of reasons, but the immediate impact of hook removal is poorly understood. Melissa Thompson, a student in the 2017 Biology of Marine Fishes course (co-taught by Tim Higham and Sean Rogers) at the Bamfield Marine Sciences Centre, caught 10 shiner perch via hook-and-line and 10 by net. After bringing them back to the lab, she used high-speed video to examine how feeding performance differed between the two groups. She found that the speed of the prey being drawn in by suction was lower in the group with hook injuries. This was further investigated using computational fluid dynamics, which was used to model the impact of the hook-induced hole on the flow of water into the mouth during feeding. This confirmed that the hole cause by the hook reduced the speed of water drawn in through the front of the mouth by causing a “leak” in the system. Although the results were significant, long-term impacts are unlikely. Rapid healing could mitigate the negative impacts, but altered behavior (i.e. different feeding strategy) during healing could also limit the negative caused by reduced suction performance. Future research should explore the roles of hook-induced injuries in other species, but also the healing time and the timeline associated with the restoration of feeding performance.
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Thompson, M., S. Van Wassenbergh, S.M. Rogers, S.G. Seamone, and T.E. Higham. 2018. Angling-induced injuries have a negative impact on suction feeding performance and hydrodynamics in marine shiner perch, Cymatogaster aggregata. Journal of Experimental Biology. 221, jeb180935