Acoustic Distribution Maps of Phonating Species in Coral Reefs

Acoustic Distribution Maps of Phonating Species in Coral Reefs

Coral reef is a vulnerable and diverse ecological system in the ocean. The reef soundscape is also diverse and encompasses biophony, geophony and anthrophony. However, extracting specific target sounds of aquatic animals has been difficult in a coastal and noisy environment. In the present study, phonations of small animals in coral reefs, such as damselfish and crustaceans, were recorded passively; using a paddling kayak as a silent platform, faint vocalizations of individual fish and crustaceans could be detected location by location during 3 days of operation. The data provided acoustic distribution maps of different animals in an area approximately 3,000 m x 500 m east of Sesoko Island, Okinawa, Japan. Passive acoustic monitoring using a silent platform and a small towing hydrophone could be a simple solution to visualize the distribution of phonating animals in shallow noisy waters. A potential application of this solution could be assessing the noise effect of coastal engineering works on aquatic animals.