SONOMAY 2022 - 2024
In collaboration with the French Office for Biodiversity (OFB) through the Mayotte Marine Natural Park (PNMM), we implement Passive Acoustic Monitoring on Mayotte coral reefs over the period 2022 - 2024.
In Mayotte as elsewhere, coral reef monitoring is based until now on snapshot visual surveys carried out in situ by biologist divers. However, these visual assessments are biased by the subjectivity and degree of expertise of each observer, and by water turbidity variations. Variations in the time of day, lunar phase or season of the surveys are additional biases.
SONOMAY (Soundscapes of Mayotte) is an applied research project that aims to develop a new approach, Ecoacoustics, as a management tool for the coral reefs of the PNMM.
The project proposes the punctual acoustic monitoring (continuous recording over 24 hours) of 43 sites usually monitored by a snapshot visual method, and the comparison of the respective contributions of the two methods. It also proposes to implement the continuous monitoring of 4 sites of interest in order to develop this long term approach and initiate the response to certain management issues of the PNMM.
continuously monitored sites over 1 year
continuously monitored sites over 24 hours
SONOMAY has four objectives
Define a reference state of Mayotte outer reef slope soundscapes both in space (24 h recordings on 43 sites) and time (one year recordings on 4 sites)
Collected raw acoustic data are archived. These archives constitute a durable heritage of Mayotte reef soundscapes and can be analysed again in the future according to new developments of Ecoacoustics. The acoustic data collected are valued in scientific popularisation actions for the general public.
This ecoacoustic calibration is based on the soundscapes and videos recorded over 24 hours on the 43 sites. In the future, it will allow us to evaluate the fish assemblage structure on outer slope sites only relying on the soundscapes recorded there. Additional ecoacoustic indices are also computed to provide a holistic ecosystem assessment.
We are particularly interested in quantifying noise pollution from passing motorboats and in identifying specific periods of biological activity. Among these specific periods, we are looking in priority for those that may be related to reproductive aggregations of commercial interest species such as groupers or snappers.
Evaluate the redundancies and complementarities between the visual and ecoacoustic monitoring methods
A committee of experts will discuss the results of this analysis as well as the results of the temporal monitoring. The aim is to establish recommendations on the most relevant ecoacoustic indices to be integrated into MPA managers' and other stakeholders' dashboards.