Microphytobenthic community development under different hydrodynamic conditions nearby the rocky outcrops of the northern Adriatic Sea

Microphytobenthic abundance and community composition were studied in the surface sediments collected nearby 12 rocky outcrops and related to the intensity of the prevailing bottom currents obtained from a numerical model. Three groups of outcrops were highlighted in which diverse benthic diatom assemblages developed, according to different hydrodynamic conditions. In the areas characterized by relatively weak bottom currents, mostly taxa that are loosely associated with the sediments proliferated. In contrast, in the areas where the bottom currents are more intense mostly species able to attach to the sediment grains were selected. These preliminary results suggest that the velocity of the prevailing currents is one of the main drivers of the development of different microphytobenthic assemblages nearby the rocky outcrops of the northern Adriatic Sea.