Fish Behaviour and Fishing Gear

A theoretical model of shoaling behavior based on a consideration of patterns of overlap among the visual fields of individual members

“…1 (adapted from Wardle 1986). First, we consider only the simple case of a two-dimensional field of view lying within a horizontal plane parallel to the fish's longitudinal axis (Fig.…”

“…Notable exceptions to this are recent attempts to model the movements of schooling fish, which recognize that individuals have a blind zone (e.g., Aoki et al 1986;Huth and Wissel 1994) and efforts to model the interactions of a school with a predator (Hall et al 1986) or trawl (Wardle 1986). The latter two studies are particularly important as they are the first to attempt to explain some aspects of shoaling behavior as arising from the individual responses of members to a predator entering its visual field, where there is a directional bias in the prey's ability to detect the predator.…”

“…The purpose of this paper is to present a theoretical exploration of how characteristics of a fish's visual field, such as the angle of view, can be used to model some aspects of shoaling behavior. We expand on the work of Hall et al (1986) and Wardle (1986) to consider more fully how the visual field characteristics may affect predator-prey interactions and most importantly to consider the importance of overlap among the visual fields of shoaling fishes to these interactions. However, we limit our conceptual model to small groups and do not directly incorporate other aspects of schooling behavior, such as social communication, water clarity, range of vision, and school movements.…”

Fish Behaviour, Learning, Aquaculture and Fisheries

“…Fishermen have reported an easily recognisable blind cod found in pots over and over again even though it was repeatedly caught and handled, and we have also caught the same tagged cod six times in a fish trap (Kristiansen, personal observations). Similarly, the complex reaction of schooling fish to a moving trawl with the fishes exposed to multiple stimuli from the gear and school mates (Wardle 1993) may create emergent properties that make the fish go through a chain of events that make it difficult for them to associate their initial reaction to the herding ropes with the subsequent negative experience of the trawl.…”

Neural mechanisms underlying escape behaviour in fishes

“…To the fisheries biologist, an understanding of the forms of escape used by different fishes could obviously have practical implications for the design and use of fishing gear (Wardle, 1986). To the specialist in biomechanics, very rapid movements are particularly consecutively by the swimming fish.…”