Biofouling dans le contexte des énergies marines renouvelables : étude des communautés procaryotes et eucaryotes et des paramètres physiques structurants

Biofouling is a process at the origin of many adverse effects in the field of marine renewable energy (MRE) where the effects and extent of biocolonization are still unknown. Within the framework of the ABIOP+ project, the objective of this thesis was to better understand the colonization mechanisms specific to MRE sites. The diversity and composition of eukaryotic communities were first evaluated through different molecular approaches in order to detect the widest range of taxa from samples collected in several contrasting marine environments. Secondly, this thesis focused on the factors influencing the colonization dynamics of biofouling communities, in particular the effect of hydrodynamics. An in situ and semi-controlled approach was carried out by evaluating the responses of the communities to different hydrodynamic conditions. For this, a multi-scale characterization of the biofilms thus formed was undertaken via complementary approaches linking metabarcoding (prokaryotes and eukaryotes), non-targeted metabolomics, biochemical assays and microscopy. Finally, we studied the eukaryotic communities in different EMR sites in the Atlantic and Mediterranean submerged between 3 and 24 months. Measurements of general biofouling characteristics (biomass, biovolume, density, ...) and molecular taxonomy approaches revealed differences in eukaryotic communities.