Assemblages on human-made structures in the North Adriatic Sea

The aims of the present study were to map all human-made structures occurring along 40 km of the Emilia- Romagna coasts (Italy) and to explore how the distribution of colonising epibiota varied in relation to a number of selected key features of the structures. For each structure, several parameters were recorded, including: location, type of structure, size, shape, height, age, distance from shore, size of gaps between structural units, construction material and abundance of conspicuous species of intertidal epibiota. A total of 133 structures were identified and mapped: these were mainly groynes, breakwaters, sea walls, harbour structures and pontoon pilings. Most structures were built with natural calcareous rock, while concrete, wood and metal structures were less common. Other parameters, such as age, distance from shore, gap-size and length, were very variable. The composition and abundance of species varied in relation to location of the structures. Differences in the abundance of epibiota also occurred among different typologies of human- made structures, between landward and seaward sides of the breakwaters and among structures of different material. Other factors explained only a limited amount of variability in the data set.