An integrated approach to understanding noise stress in two auditorily diverse species of freshwater fish

Anthropogenic noise can have negative consequences on a fish’s ability to survive and reproduce and has been increasing over the past decades. To determine the integrated effects of anthropogenic noise on two auditorily-diverse freshwater fish species; yellow perch ( Perca flavescens) and spottail shiner ( Notropis hudsonius), the current study assessed behavioural, physiological, and transcriptional metrics. Fish were exposed to anthropogenic noise or control sounds in a semi-captive field setting and behavioural changes, blood cortisol levels and relative transcription were analyzed for effects of anthropogenic noise. Results showed little effect of noise on yellow perch; however, spottail shiners were affected by noise at multiple levels of organization. Additionally, blood cortisol levels showed indications of handling stress in both species overriding any potential effects of noise. For the first time, the current study differentiates stress effects from handling and those induced by environmental noise and shows that ecological impacts of anthropogenic noise can be both species- and metric-specific, indicating a need for a more systematic approach when analyzing potential noise impacts.