The Department of Physics colloquia includes internationally prominent guest speakers. They take place on Fridays during the semester and are open to anyone from the university, with students encouraged to attend.
Dr Sophie Nedelec
Dr Sophie Nedelec, University of Exeter
Coral reef soundscapes and boat noises
Abstract: Sound is relatively important for fish because it propagates far in comparison with light, and independently of currents in contrast to chemical cues, underwater. Therefore, underwater sound is rich in information about the properties and inhabitants of the surroundings. Most of the ears in the ocean belong to fishes and invertebrates and function as accelerometers, using sound particle motion cues for communication, orientation and habitat selection. Coral reefs are particularly rich and diverse habitats where fishes and invertebrates live in vibrant soundscapes. But coral reefs are vulnerable to underwater noise pollution. Anthropogenic noise is a pollutant of international concern, with mounting evidence of impacts on animal behaviour and physiology that are pervasive across taxa, ecosystems and the world. Recent work from Dr Nedelec and her team shows that underwater noise affects all stages of the life cycles of fishes that inhabit fragile coral reef habitats. Stressed and badly behaved fishes are pushed to their limits, with impacts on survival.
But the tide could turn on noise pollution. Dr Nedelec’s team experimentally tested the hypothesis that protecting vulnerable habitats from noise pollution can improve animal reproductive success. Using a season-long field manipulation with an established model system on the Great Barrier Reef, the spiny chromis, they demonstrated that limiting motorboat activity on reefs leads to the survival of more fish offspring compared to reefs experiencing busy motorboat traffic. A complementary laboratory experiment isolated the importance of noise and, in combination with the field study, showed that the enhanced reproductive success on protected reefs is likely due to improvements in parental care and offspring growth. Noise mitigation and abatement offer simple wins in protecting coral reefs from human impacts, and present a valuable opportunity for enhancing ecosystem resilience.