Swimming bass under pounding bass : fish response to sound exposure

Fish live in a world that is not silent. In fact, fish hear low frequency sounds and may need them for navigation, predator-prey interactions and mate attraction. Due to their dependence on sounds, fish may be particularly sensitive to changes in their acoustic world. Since the 1900s, the acoustic world of fish has been altered by a new prominent sound source: human activities. These activities generate a cacophony of high-intensity sounds. At close range, they may cause tissue damage and temporary hearing loss. At further distances, more moderate sounds may cause auditory masking, behavioural changes and reduced efficacy in foraging and avoiding predators. Assessing the severity of behavioural impacts of sounds is not straightforward and are often problematic.This thesis used European seabass to study behavioural effects of man-made sounds of different temporal structures. It also compared the effects of tank-based experiments with open-water experiments. Finally, this thesis studied the habituation of fish to sound exposure and how sound effects are influenced by various environmental factors.