Marinas: An overlooked habitat for exploring the relation among polychaete assemblages and environmental factors

The increasing number of anthropogenic areas in the marine environment results in significant impact to adjacent ecosystems. In fact, the presence of marinas modifies the original environmental conditions and ends up disturbing the faunal community. However, despite the essential role displayed by the macrofauna on marinas' fouling biota, certain taxa such as polychaetes have been poorly studied. The present study provides the first spatial characterization of the epibiont polychaete fauna associated with the bryozoan Bugula neritina in marinas along the Iberian Peninsula and the north of Morocco. A total of 32 polychaete species were identified, with Syllidae being the most diverse family. Furthermore, the environmental factors involved in the occurrence and abundance of the dominant species Salvatoria clavata were also analyzed by Generalized Linear Models; results showed that the highest predicted values of S. clavata abundance appeared at marinas with high levels of nutrient enrichment and of heavy metals concentration.