From physiology to policy: a review of physiological noise effects on marine fauna with implications for mitigation

The development of guidelines for mitigating noise impacts on marine fauna requires data about the biological relevance of noise effects and about the practicality of mitigation options. Recent expansion of scientific knowledge has shown that noise effects vary among animals with different behavioral ecophysiology. Beaked whales exemplify that some sensitive species may experience negative effects of sound at kilometers from the source, due to behavioral reactions leading to indirect physiological damage. Moored hydrophone arrays have contributed substantially to our understanding of naval sonar effects on beaked whales and have been used to refine techniques for passive acoustic detection of cetaceans. Similarly, broadband Ocean Bottom Cables/Nodes could facilitate learning about effects of seismic sounds and cetaceans' distribution offshore. This information is essential to improve spatial mitigation in the planning-phase of activities. Also, passive acoustics can help real time mitigation, which requires early detection of vulnerable species and practical mitigation protocols triggered by detection. Detection could be aided by large-scale portable acoustic arrays, which are now technologically feasible. Pilot studies of technological applications for mitigation and cost-benefit modelling of potential mitigation scenarios will help to inform effective mitigation design. Mitigation reduces social conflict regarding noise effects, a win-win for all stakeholders.