Numerous fish and invertebrate species produce a variety of clicks and grunts that combine to create a surprisingly loud noise. Previous studies had shown that after spending their first few weeks in the plankton, larval fish and corals searched for somewhere to settle by listening for, and moving towards, this reef noise.

In a study published in the Journal of Experimental Marine Biology and Ecology, a team led by University of Exeter PhD student Emma Kennedy analysed recordings of coral reefs from the Las Perlas Archipelago in Panama. They found that healthier reefs were louder, with a clear correlation between overall noise levels and the amount of living coral. More detailed analysis revealed that higher frequency sounds provided information about a reef’s coral diversity, while lower frequency sounds gave an indication of fish abundance.

‘This study provides evidence that reef-generated sound contains a real richness of information,’ said Kennedy’s supervisor, Dr Steve Simpson, who also participated in the study. ‘This would provide fish and invertebrates with the cues they need to assess the quality of potential settlement sites before they can see them. It may even provide the information that enables some fish to return to the very reef on which they were originally spawned.’

November 2010