Microbes associated to macroorganisms in coral reefs: A missing and vulnerable biodiversity hot-spot ?

Leaders: Thierry Bouvier and Sébastien Villéger



Fish and corals are among the most emblematic species of the high biodiversity found in coral reefs. However, coral reef biodiversity is not limited to the diversity of macro-organisms, since microorganisms living in the water column or on the sediment and rocks are abundant, as well as microbes living at the surface of macroorganisms. Nevertheless, there is still no assessment of the biodiversity of such epibiotic microorganisms in coral reef ecosystems. As reef macroorganisms are facing increasing anthropogenic disturbances, assessing their associated microbial biodiversity is an urgent need to predict the consequence of their erosion on the total biodiversity of coral reefs, i.e. including microorganisms, and hence on their functioning. To reach these objectives we will sample the Bacteria, Archaea and Eukaryotes components of the surface microbial diversity from representative reefs macroorganisms, including corals, echinoderms and fishes. We will assess the biodiversity facets of animal surface microbiomes using high-throughput DNA sequencing techniques and test for their ecological and evolutionary determinants. We will then measure contribution of animal-associated microbial diversity to the whole reef microbial biodiversity and eventually estimate its vulnerability to human impacts using realistic scenarios of macroorganisms loss under climate warming and overfishing.