Implications of Multimodal Integration and Masking on Acoustic Deterrent Efficacy

Acoustic deterrents are popular form of behavioral guidance measure used to manage fish movements in rivers. However, despite their popularity, the reported efficacy of these systems is often quite variable. One potential reason for this is that peripheral sensory inputs can influence how fish respond to deterrent stimuli. While little research has examined these effects in relation to deterrent function, they have been well studied for many decades in different contexts. Therefore, this chapter provides a brief review of literature pertaining to how multimodal integration and masking influence fish behavior and suggests how this vast body of literature may inform the design and implementation of acoustic deterrents in the future. Highlighted is the need to understand the sensory background against which deterrents operate, as peripheral sensory information may impact the perception of and thus behavioral response to a given deterrent stimulus. Furthermore, acoustic masking may impair a fish’s ability to properly distinguish acoustic deterrents from background noise. Improving acoustic deterrent efficiency will require complimentary approaches, utilizing fieldwork to quantify the sensory environment present against which acoustic deterrents must function, and controlled experiments to elucidate the relationships between these conditions and fish behavioral responses to deterrent stimuli.