EFFECTS OF ANTHROPOGENIC NOISE ON ANTIPREDATOR REACTIONS AND BOLDNESS IN A FRESHWATER FISH

Abstract

Anthropogenic noise pollution is increasing on a global scale, yet research aimed at understanding the potential impacts of anthropogenic noise is lacking. Detrimental effects of anthropogenic noise on marine species include altering hearing sensitivity, foraging, navigation, communication, boldness, and even risk perception. In freshwater systems, little is known regarding how anthropogenic noise impacts antipredator behaviour and boldness of prey fishes. To investigate such potential impacts, I exposed fathead minnows, Pimephales promelas to a playback of field recorded motorboat noise while exposing them to chemical alarm cue – an indicator of predation risk. I found that the boat noise exposure led to impaired antipredator responses to risk cues. I then examined effects of chronic lab-based noise on boldness in fathead minnows. I exposed minnows to either a familiar airstone noise or a novel filter noise for 8 days and then measured the latency of minnows to emerge from an isolation chamber as a standard measure of boldness. I found that minnows decreased their boldness with exposure to the novel acoustic environment. Surprisingly, I found no evidence for acclimation to the novel noise over the 8-d period. I also found that minnows recovered from the stress of the novel acoustic environment sooner when they were transferred to their familiar noise environment. My data suggest that aquatic species are negatively affected by anthropogenic noise both in their natural habitat and in the laboratory. My data indicate that management plans should consider taking action to mitigate noise pollution.