Abstract
Noise from human activities has increased and been shown to negatively impact marine animals. Marine mammals and fish are vulnerable to anthropogenic noise because they rely on sound to communicate, find food, avoid predators and sense their environment. Forage fish are small schooling pelagic fish, important to many predators and instrumental in moving energy to higher trophic levels. There are limited studies investigating how noise influences forage fish behaviour, especially their anti-predator behaviour. Here, we investigate how noise from boats, pile driving and wind farms affects the anti-predator behaviour of Pacific sand lance (Ammodytes personatus, PSL), a key forage fish in the Northeast Pacific Ocean. We exposed PSL to four different noise playbacks and documented anti-predator behaviour (i.e., burying in the sand and startling). We hypothesized that exposure to anthropogenic noise would increase anti-predator behaviour in PSL. Contrary to our hypothesis, exposure to boat noise and pile driving noise decreased startling behaviour and burying behaviour, while wind farm noise increased both. These results suggest that different noise sources may impact behaviour through different mechanisms such as noise-induced stress or distraction and, as a consequence, can both increase PSL short- term availability in some contexts while decreasing availability overall. Understanding how fish and their predators respond to different noise sources over longer periods of time is critical in understanding the effects of noise on marine communities and necessary to facilitate recommendations on the management of marine anthropogenic stressors and highlight conservation efforts for coastal areas.