Sources of anthropogenic pollution were categorised by combining elemental and isotopic techniques (C/N ratios and δ¹³C, δ¹⁵N) on samples of surficial sediments in the harbour of Naples (Southern Tyrrhenian Sea, Italy). The study area, due to the intense and diversified industrial and commercial activities, is an appropriate natural laboratory to verify reliability and relevance of geochemical methodologies applied to exploration of sources, pathways and fate of contaminants in highly polluted coastal marine systems. Application of cluster analysis to the whole dataset and resolution of a δ¹³C and δ¹⁵N Moore–Penrose system equation provided information to reliably discriminate and identify anthropogenic point sources in the studied sediments. In particular, effects of oil spilling and wastewater discharge within the area of the harbour of Naples were clearly discriminated thus suggesting high-potential of the two numerical techniques, applied to the C and N elemental and isotopic values, to explore effects of anthropogenic impact in marginal and confined coastal basins. The δ¹⁵N values showed high sensitivity to discriminate sewage discharges (treated or untreated organic matter), clearly indicating the point of emissions. The δ¹³C shows indirect capability of discriminating crude oil and petroleum products.

The Strait of Sicily plays a crucial role in determining the water-mass exchanges and related properties between the western and eastern Mediterranean. Hydrographic measurements carried out from 1998 to 2013 allowed the identification of the main water masses present in the Strait of Sicily: a surface layer composed of Atlantic water (AW) flowing eastward, intermediate and deep layers mainly composed of Levantine intermediate water (LIW), and transitional eastern Mediterranean deep water (tEMDW) flowing in the opposite direction. Furthermore, for the first time, the signature of intermittent presence of western intermediate water (WIW) is also highlighted in the northwestern part of the study area (12.235° E, 37.705° N). The excellent area coverage allowed to highlight the high horizontal and vertical inter-annual variability affecting the study area and also to recognize the permanent character of the main mesoscale phenomena present in the surface water layer. Moreover, strong temperature-salinity correlations in the intermediate layer, for specific time intervals, seem to be linked to the reversal of surface circulation in the central Ionian Sea. The analysis of CTD data in deeper water layer indicates the presence of a large volume of tEMDW in the Strait of Sicily during the summers of 2006 and 2009.

A number of scientific papers in the last few years singled out the influence of environmental conditions on the spatial distribution of fish species, highlighting the need for the fisheries scientific community to investigate, besides biomass estimates, also the habitat selection of commercially important fish species. The Mediterranean Sea, although generally oligotrophic, is characterized by high habitat variability and represents an ideal study area to investigate the adaptive behavior of small pelagics under different environmental conditions. In this study the habitat selection of European anchovy Engraulis encrasicolus and European sardine Sardina pilchardus is analyzed in two areas of the Mediterranean Sea that largely differentiate in terms of environmental regimes: the Strait of Sicily and the North Aegean Sea. A number of environmental parameters were used to investigate factors influencing anchovy and sardine habitat selection. Acoustic surveys data, collected during the summer period 2002–2010, were used for this purpose. The quotient analysis was used to identify the association between high density values and environmental variables; it was applied to the entire dataset in each area in order to identify similarities or differences in the “mean” spatial behavioral pattern for each species. Principal component analysis was applied to selected environmental variables in order to identify those environmental regimes which drive each of the two ecosystems. The analysis revealed the effect of food availability along with bottom depth selection on the spatial distribution of both species. Furthermore PCA results highlighted that observed selectivity for shallower waters is mainly associated to specific environmental processes that locally increase productivity. The common trends in habitat selection of the two species, as observed in the two regions although they present marked differences in hydrodynamics, seem to be driven by the oligotrophic character of the study areas, highlighting the role of areas where the local environmental regimes meet ‘the ocean triad hypothesis’.