Hook retention but not hooking injury is associated with behavioral differences in Bluegill

Abstract Recreational catch-and-release angling (C&R) is prevalent and growing in popularity, along with concerns over the welfare of released fish. Although there have been many studies quantifying post-release mortality in fish exposed to C&R, there is growing interest in understanding and minimizing any sublethal consequences of recreational fisheries interactions with the aim of improving fish health and welfare. Short-term fish behavior has been explored as an endpoint for C&R, but effects of hooking injury have not been examined independently of other angling stressors. We used Bluegill (Lepomis macrochirus) as a model to assess whether immediate injuries from hooking or the retention of a hook influenced fish behavior compared to unhooked controls using Z-maze and flight initiation distance tests. Fish that retained a hook were less likely to leave a refuge-emergence chamber than fish that were hooked–unhooked or unhooked controls. Moreover, when fish with the hook retained did leave the refuge, they were less exploratory than fish in the other two treatments. Unhooked control fish and fish that were hooked-unhooked did not significantly differ in their overall behavioral patterns outside the refuge. This suggests that fish are resilient to the acute tissue damage associated with minor hooking injuries and that reported behavioral impairments in fish after release are driven more by hook retention, physiological exhaustion from the fight, landing, and/or subsequent handling and air exposure.