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Numerous anthropogenic activities take place within or nearby ports, thereby increasing environmental pressure in coastal zone that become the final destination of many environmental contaminants. Thus, port areas are crucial to understand the possible long-term effects of contaminants on metazoans that are at the base of the food webs. The port of Vado Ligure is the outlet to the sea of one of the largest industrial areas of the West Liguria (NW Mediterranean). Sediment quality was evaluated in twenty-eight stations at increasing distance from the port. The nematode fauna was characterised (i.e., assemblage composition, taxonomic diversity and functional traits) and organic matter quantity and composition and contaminant concentrations (heavy-metals, polycyclic aromatic hydrocarbons and heavy, long-chain hydrocarbons) were measured. The area resulted mainly polluted by mercury, followed by arsenic, zinc, and polycyclic aromatic hydrocarbons. The faunal distribution (both from a taxonomical and functional point of view) appeared influenced by the contamination, as well as by sediment granulometry and organic matter content and composition. According to nematode assemblages and environmental variables, two groups of stations showed the most marked differences: one located in front of the Vado Ligure port, characterised by the most contaminated stations, the highest organic matter content, and fine sediments, and the other one, close to Bergeggi Marine Protected Area, characterised by more pristine stations, low organic matter content and coarser sediments. A suite of nematode genera that may be considered as bioindicators of pollution and organic enrichment was selected. Maturity index (MI) resulted negatively affected by contamination, suggesting that the different proportion of the nematode life-strategies is useful in assessing the environmental quality of sediments. The ecological quality status of the sampled stations obtained using abiotic and biotic descriptors (i.e., contamination level, organic matter content and nematode diversity and maturity index) was compared. Both the abiotic and nematode variables showed a general consistency for the stations of the two groups characterised by the highest and the lowest levels of contamination and organic enrichment.

Unlike the soft bottom meiofauna, meiofauna associated to hard substrata is poorly studied, despite its ecological relevance. Since communities of hard substrata are usually characterized by species with different life cycles and strategies from those of soft bottom assemblages, information on hard substrata meiofauna is still needed. In this study, sessile macrobenthos and the associated meiofaunal assemblages of two sites of Portofino (NW Mediterranean) were investigated in two seasons at three different depths on both sub-vertical and inclined reefs. The study aimed to assess the abundance, diversity and composition of the meiofauna and the factors structuring its assemblages. Moreover, as meiofauna is known to be dependent upon the substrate characteristics, the study investigated whether the meiofaunal patterns could be related to the sessile macrobenthos structure and composition, and to which extent. Macroalgae dominated the sessile macrobenthic assemblages, while Nematoda and Copepoda were the main meiofaunal groups. Meiofaunal higher-taxa richness and diversity resulted very high, due to the large number of different microhabitats offered by macroalgae. Macrobenthic assemblages were dominated by Rodophyta and Ochrophyta in summer, the latter dramatically collapsing in winter. The meiofaunal abundance and composition changed significantly with the season, consistently with the sessile macrobenthic assemblages, and resulted strongly correlated with Ochrophyta. Shaping the meiofaunal assemblages, macroalgae appeared to act as ecosystem engineer for the meiofauna.

The Water Framework Directive (WFD) strengthened the need for the protection and enhancement of Ecological Quality Status (EQS) in water bodies of EU Member States. However, in terms of the EQS assessment, there is a lack of detailed studies that assess the consequences of dredging, especially concerning macrobenthic communities. Therefore, the main objective of this study was to evaluate the EQS assessment, as important need to WFD, based on diversity and ecological quality indices after dredging activity. Data was collected in Mondego estuary, Portugal, between October 2007 and November 2008, within and around the area to be dredged (3 ha): one dredging occasion and ten sampling dates along one year. Physical–chemical changes were examined. The relative performance of Margalef, Shannon–Wienner, AMBI–AZTI Marine Biotic Index and the multimetric BAT –Benthic Assessment Tool (BAT) were analyzed before and after dredging. In the first days, dredging increased the share of fine and coarse sand sediment and had changed TSS, POM and SOM, affecting the macrofauna assemblages. Two months after the dredging, the number of taxa, density, diversity and ecological indices showed similar values to pre-dredging conditions and one year later the number of species and density values almost duplicated. However, the macrofauna composition and structure were still significantly different in relation to pre-dredging and the biomass values did not return to the original values. Nevertheless, BAT was sensitive to the changes that occurred in the area, showing that the system recovered to pre-dredging values after one year, in terms of EQS. The present work reinforced the robustness of BAT as an accurate ecological quality assessment tool.

Meiofauna in sediments colonized by Posidonia oceanica in the Ligurian Sea (NW Mediterranean) was investigated to evaluate its use as an early warning indicator of environmental disturbance. Descriptors commonly used in seagrass health assessment are mainly related to the plant (e.g., phenological parameters) and/or to the meadow (e.g., structural parameters) and are subjected to long-term response times. Conversely, meiofauna is considered a good bioindicator with a rapid response to environmental variations, due to its main features (e.g., short life cycle, scarce mobility, presence/absence of tolerant/sensitive species). Meiofaunal community, sediment characteristics and organic matter descriptors in three meadows located in urbanized coastal areas were contrasted with those observed in three meadows located within Marine Protected Areas. Samplings were carried out in two distinct periods, at the beginning and at the end of the summer season, in order to individuate early changes in the meiofaunal assemblages. The meiofauna and, particularly, the nematode assemblage composition and diversity, highlighted differences among meadows at the end of the summer not detectable by organic matter descriptors and structural parameters of the meadow (e.g. shoot density). Nematodes are, thus, proposed as appropriate biological quality elements (BQEs) able to show early responses to environmental disturbance.

The spatial distribution and structure of nematode assemblages in the area surrounding the harbour of Vado Ligure (Savona, NW Mediterranean) were studied in relation to the influence of natural and anthropogenic environmental factors. Stations were selected following an “anthropogenic gradient” from sites located near the city centre and its harbour to more pristine and distant sites. Sediment quality was determined by considering both sediment granulometric and chemical parameters (hydrocarbons, heavy metals, total organic matter, proteins, carbohydrates) as well as nematode abundance, diversity, life strategies, trophic structure and assemblage composition. A high correlation between environmental characteristics and the nematode response was found. On the basis of the comparison of these results, which identified three distinct sub-areas associated with different levels of environmental quality, a set of nematode indicator genera was selected for the future evaluation of quality status.