Strike behaviour and behavioural responses to retrieval by northern pike (Esox lucius) during ice angling

Behaviour of fish during catch and release has not been well studied despite its potential importance for fish conservation and welfare. We used video footage to examine behaviours of ice-angled northern pike (Esox lucius) during approach and retrieval. Initial approach behavior by pike was slow and appeared to involve assessment of the dead bait presented prior to striking. Based on 42 captures, we determined that pike responded to hook set and retrieval with the common behaviors of thrashing, dashing, or rolling in the line. The use of different hook styles (treble vs. 0° offset circle hooks) influenced both the occurrence of behaviours and the proportion of time spent exhibiting them. Rolling in the line makes retrieval through the ice difficult and may cause fish injury. Ultimately, our study provides new insight into fish behaviour and suggests that tackle may have an important influence on how fish respond to being captured.