Getting Scarce and Lure Shy: Impacts of Recreational Fishing on Coastal Northern Pike (Esox lucius) Abundance, Size Structure and Vulnerability to Angling

Abstract

Controlled experiments have shown that northern pike (Esox lucius) is able to develop lure avoidance, but whether such patterns exist in the wild is unknown. We assessed the impact of recreational fishing on a natural population of pike in the southern Baltic Sea, from samples of three pairs of partially protected areas (pMPA) and nearby unprotected sites. Pike were 2–4 times more abundant inside pMPAs than outside in sites open to fishing. The mean size of pike was not greater in pMPAs, but protected sites hosted more exceptionally large fish than sites open to fishing. Pike in sites with reduced recreational fishing effort were more aggressive to artificial lures. About one-third of the catch rate differences among pMPAs and open sites could be attributed to lure shyness. Collectively, our work shows that recreational fisheries exploitation of coastal pike reduced abundance, truncated the size structure of the largest individuals, and contributed to fisheries-induced timidity through reduced reactivity to lures.