Soundscape of protected and unprotected tropical Atlantic coastal coral reefs

Abstract

Behavioural patterns and distributions of crustaceans, fish and mammals can be inferred from acoustic recordings of the extremely noisy marine acoustic environment. In this study, we determined the soundscape of protected and non-protected marine areas between January and April 2016. Sonobuoy (a device for sound monitoring) recordings began at sunset and lasted approximately 12 hours per day. The results show a complex soundscape dominated by biological sounds produced by crustaceans and fish. Six fish chorus-dominant frequencies between 200 and 1000 Hz occurred at a similar time each day, except for chorus I. The choruses consisted of high-energy callings after the last reef line within the protected area. However, fish choruses showed low energy levels in unprotected areas. The results show the importance of protected areas for fish populations and the usefulness of passive acoustics to monitor biodiversity of sounds of commercial fish in Brazilian tropical costal reefs.