False alarm: The effects of boat noise on the anti-predator behaviour in Pacific sand lance
Date
2024
Authors
White, Meredith
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Publisher
University of Victoria
Abstract
Underwater noise from commercial shipping and recreational boating has remarkably increased in recent decades and has been widely shown to negatively impact marine animals. Many marine mammals and fish are affected by boat noise because they rely on sound to communicate, find food, avoid predators, and sense their environment. Compared to marine mammals, fewer studies have investigated how boat noise influences fish behaviour, especially anti-predator behaviour. I investigated how boat noise impacts the anti-predator behaviour in Pacific sand lance (PSL), a coastal schooling fish that is important as prey for numerous seabirds, fish, and marine mammals. For twelve days, PSL were held in two laboratory tanks: in one I played boat noise recordings, and in the other did not, and their anti-predator behaviour (e.g., burrowing in the sand and startling) was recorded by watching the underwater video footage. I found that PSL startled at a greater rate on days when they were not exposed to boat noise compared to days exposed to boat noise. These findings suggest that boat noise masks the auditory cues that stimulate PSL startling behaviour, which may negatively impact their fitness and increase their availability as a prey source.
Description
Keywords
Anti-predator behaviour, Pacific sand lance, boat noise, predator-prey interactions