Résumé
The rising levels of anthropogenic noise in marine environments have made understanding its ecological impacts a critical challenge for biodiversity management. Noise emissions from recreational motorboats are likely to threaten the health of coral ecosystems by altering key ecological processes such as the control of algal blooms by herbivores. To investigate this, we conducted an acoustic playback experiment in the lagoon of Bora-Bora (French Polynesia) to assess the activity of the convict surgeonfish, Acanthurus triostegus, when exposed to motorboat noise in enclosures. After 10 days, total algal cover was reduced by the presence of fish, but significantly less in the presence of boat playback. Our results suggest that anthropogenic noise could mediate the algal-coral competition and exacerbate the shift from coral-dominated to algal-dominated reefs. Given the predicted continued increase in underwater noise levels, ecological aspects need to be investigated in order to better protect and manage valuable areas.