Does catch-and-release angling pose a threat to American eel? A hooking mortality experiment

Incidental capture of protected fishes usually calls for immediate release, however, post-release survival has not been investigated for many protected species. The American eel Anguilla rostrata is an example of an imperiled species that is incidentally captured by recreational anglers, but for which the impacts of catch and release are unknown. In this study, we examined the short-term (7 d) mortality and injury of American eels (n = 207) following simulated catch-and-release scenarios (involving manually embedded hooks) in a controlled experiment. Specifically, we compared the effects of cutting the line versus removing the hook, as well as shallow versus deep hooking, in holding tanks. No mortalities occurred in any of the groups during a 7 d monitoring period, and most eels exhibited little to mild injury. A high degree of hook shedding occurred in groups where the hook was shallowly embedded. Hooking depth was significantly related to hook-shedding rate, with 93.7 % of hooks shed in the shallow-hook-line-cut group compared to 71.8% of hooks shed in the deep-hook-line-cut group. Our results suggest that recreationally captured American eels may be relatively resilient to catch and release, but validation of these results in a field setting is recommended.