Patterns of colonization and succession of benthic assemblages in two artificial substrates

Benthic communities colonizing two different typologies of artificial structures, Tecnoreef® pyramids (PY), and plinth modules (PL), differing for material and shape, were investigated for three years after their deployment on a soft bottom offshore Pedaso (Western Adriatic Sea). The aims were to describe the colonization patterns of benthic assemblages on the two artificial modules, to highlight possible differences between them and to detect the effectiveness of the artificial reef on the ecosystem functioning. The composition of the benthic communities settled on the two types of artificial substrates was different especially just after the reef deployment. Abundance and species richness were higher on PL in the first two years, while an explosion of individuals characterized PY in the third year. This suggested a delay of about one year in the colonization processes on PY likely due to the material and shape. The community settled of the artificial structures was dominated by hard-substrate species which are commonly absent in the natural environment. The occurrence of these organisms enriched the local soft-bottom communities and contributed to habitat diversification. This, together with the importance of these species in the diet of a few reef-dwelling fish, confirms the trophic role and the ecological importance of artificial reefs in areas characterized by soft seabed.