The ORE sector is expected to grow strongly between 2015 and 2020, in Europe and in France. The first prototypes are currently being installed or built at demonstration sites. There is a need for better knowledge of the natural environment of the potential sites. The impact of the turbines must be evaluated objectively and initial states of the operating areas are in progress. The benthic compartment, which includes the substrate and the fauna and flora that grows on the seabed, plays a key role in the functioning of coastal ecosystems. However, to date, knowledge of the potential impacts of ORE on this compartment is extremely patchy.