• fouling
• marine turistiche
• Mar Mediterraneo
• comunità di artropodi
• artropodi
• Corsica
• comunità di fouling

Port areas are considered complex semi-natural environments, inhabited by biological communities composed of species able to tolerate strong variations in chemical, physical and biological parameters related to human stress. Port environments are characterized by fouling communities, namely associations of marine organisms that thrive on hard, artificial or natural substrates, regardless of the spatial and temporal extent of the association. In these communities, arthropods constitute one of the most represented taxa in terms of species richness and abundance. Moreover, these organisms are affected by the abiotic variations of the environment in which they live, showing variations in the community structure linked to the different type of disturbance which they are subject to.
The purpose of this work was to assess the differences in the composition of arthropodofauna in an area of the Northern Tyrrhenian Sea poorly studied, taking into consideration four touristic marinas in order to estimate the spatial distribution of the arthropods present to theirs and to estimate the small-scale spatial heterogeneity.
Four marinas along the Corsican coasts have been identified: Île-Rousse, Saint Florent, Bonifacio and Porto Vecchio. In each marina three randomly selected areas were considered, and three replicates for each area were sampled. Samples were collected by scraping known surfaces along submerged artificial docks in June 2019, then transferred to the lab in Pisa. The arthropodofauna was separated using a stereomicroscope, identified to the lowest taxonomic level possible, and counted.
The Shannon-Wiener and Pielou diversity indexes were calculated from the collected data. Data analysis was carried out with methods of multivariate statistical analysis, using the software PRIMER-E, through multidimensional Scaling (MDS), similarity percentage analysis (SIMPER) and PERmutational Multivariate ANalysis Of VAriance (PERMANOVA). A total of 4042 arthropod individuals, belonging to 32 species, were detected. They were predominantly Amphipoda, followed by Cirripedia, Isopoda, Tanaidacea, Decapoda, Insecta and Mysidacea. The highest value of abundance was found at Porto Vecchio, while the smallest at Île-Rousse. The most variable site, in terms of abundance and specific species richness, turned out to be Porto Vecchio, while the least variable was Île-Rousse. The most abundant species were represented by Chondrochelia savignyi (Kroyer, 1842), Apocorophium acutum (Chevreux, 1908), Tanais dulongii (Audouin, 1826) and Amphibalanus amphitrite (Darwin. 1854).
The marinas of Porto Vecchio and Île-Rousse showed mild conditions of dominance, while those of Bonifacio and Saint Florent were characterized by greater values of equitability. Chondrochelia savignyi and Tanais dulongii were also found to contribute more to the similarity between areas in individual marinas. The most dissimilar marinas were Saint Florent and Île-Rousse (99.41%).
The arthropod community in the study area was significantly influenced by the respective marina, Results of the present work showed a marked spatial heterogeneity of arthropod fauna in the study area, comparable to that found in other Mediterranean touristic marinas. The different levels of marine traffic, combined with other local anthropogenic factors could account for the high variability detected.