Discussion on “Living on the rocks: substrate mineralogy and the structure of subtidal rocky substrate communities in the Mediterranean Sea”

The present paper provides correlative evidence that the mineralogical composition of rocks may influence marine assemblages in Mediterranean shallow sublittoral rocky habitats. They point out that direct effects on sessile organisms (e.g. macroalgae) may cascade up through the entire community and aff ect higher trophic levels (e.g. carnivorous fi shes). Indeed, in seawater, aggregates, concrete or any natural or artifi cial substrata quickly become fouled [1–3] Colonization surface can be divided into two main stages, micro-fouling and macro-fouling. They are respectively characterized by the formation of bacterial biofilm on the surface and the adhesion of macro-organisms such as algae, barnacles and larvae (macro-fouling) [2,4,5]. The nature of the substrate strongly acts on material’s biorecptivity according to the literature [6,7].