‘Habitat-associated soundscape’ hypothesis tested on several coral reefs within a lagoon (Bora-Bora Island, French Polynesia)

Abstract

Coral reefs encompass different habitats that have their own living communities. The present study aimed to test the hypothesis that these different kinds of habitats were characterized by specific soundscapes. Within the lagoon of Bora-Bora, acoustic recordings and visual surveys of substrate type and fish communities were conducted on four reef sites belonging to the three main geomorphological habitats (fringing reef, channel reef, barrier reef) from February to April 2021. Two acoustic parameters were measured for each site and month, during the day and at night: the peak frequency (F peak , in Hz) and the corresponding power spectral density (PSD peak , in dB re 1 µPa 2 Hz −1 ). Our results showed that each geomorphological unit could be characterized by these two parameters and therefore had a specific acoustic signature. Moreover, our study showed that a higher living coral cover was significantly positively correlated with F peak in the low-frequency band (50–2000 Hz) during day-time. Although biodiversity indices based on visual surveys did not differ significantly, fish communities and soundscapes were significantly different between sites. Overall, our study underlines the importance of passive acoustics in coral reef monitoring as soundscapes are habitat specific. Supplementary Information The online version contains supplementary material available at 10.1007/s00227-023-04206-3.

Listening to the depths of coral reefs in French Polynesia: deciphering the whoot

“…La Polynésie française est l'un des endroits au monde où nous disposons d'informations sur l'ambiance sonore tant des récifs photiques que des MCEs. En effet, une grande diversité de sons émis par les poissons a été récemment mise en évidence dans l'archipel de la Société (Bertucci et al 2016(Bertucci et al , 2017(Bertucci et al , 2020Raick et al 2023;Minier et al 2023), ainsi que dans plusieurs autres archipels de la Polynésie française (Jublier et al 2020;Raick et al 2023). Ces sons présentent des variations temporelles (Bertucci et al 2020;Raick et al 2021a) et spatiales, à la fois à une échelle horizontale (Raick et al 2021a) et verticale (Raick et al 2023).…”

“…Ces sons présentent des variations temporelles (Bertucci et al 2020;Raick et al 2021a) et spatiales, à la fois à une échelle horizontale (Raick et al 2021a) et verticale (Raick et al 2023). Ces dernières différences sont généralement liées au type d'habitat (par exemple, récif frangeant vs récif barrière ou bien mangrove vs zone sableuse) (Minier et al 2023).…”