Mooring and biofouling

The mooring lines of floating ORE systems are directly concerned by biocolonisation, but this process is poorly characterised and no scientifically justified protocol standard exists.  In order to remedy this, an experiment was initiated in the summer of 2020 in the Etel ria as part of the ABIOP+ collaborative project. For 18 months, a fixed structure containing samples of different types of anchors was immersed in order to determine whether the geometry and material of the anchors have an influence on biocolonisation. This first stage of characterisation, which can be considered static, precedes a so-called “dynamic” stage which will consist of identifying the influence of mechanical stresses, in this case elongations, on the biofouling.

The operation to recover the structure was carried out on 27 January. This was a delicate stage that was carried out with great efficiency by eight people from our team and the University of Nantes, as well as the ISMER company. Indeed, the tidal window was very short and the amount of work to be done once on land was considerable. Once labelled and listed, each colonised sample was measured: length, perimeter at several levels, diameter at different angles and heights, weight in air and water, volume. Numerous photos and videos were taken following precise protocols in order to feed a database on which an artificial intelligence algorithm is being developed. The samples were then conditioned for further work: taxonomic study on morphological criteria and molecular analysis of the metabarcoding type. To be continued in a few weeks…

Video of the launch of the experiment

Photo credit: France Energies Marines