Behaviour and survival of pike, Esox lucius, with a retained lure in the lower jaw

The behaviour and survival of pike, Esox lucius L., released with a retained lure in the mouth was studied relative to control fish, which simulated line breakage prior to landing. Behaviour was monitored during the first hour post-release with the aid of visual floats attached to the fish, and longer-term for 3 weeks, by means of externally attached radio transmitters. Lure-treated pike were less mobile during the first hour postrelease, but exhibited greater mobility and travelled further distances from the release area in the first 24 h after release than controls. From the second day after release, the behaviour of lure-treated pike was similar to control fish. No mortality occurred in a 3-week monitoring period. These results are indicative of only short-term behavioural impairments resulting from a retained lure and rapid resubmission of normal behaviour after simulated break-offs.