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This work gives an assessment of the hazard faced by Sicily coasts regarding potential offshore surface oil spill events and provides a risk assessment for Sites of Community Importance (SCI) and Special Protection Areas (SPA). A lagrangian module, coupled with a high resolution finite element three dimensional hydrodynamic model, was used to track the ensemble of a large number of surface trajectories followed by particles released over 6 selected areas located inside the Sicily Channel. The analysis was carried out under multiple scenarios of meteorological conditions. Oil evaporation, oil weathering, and shore stranding are also considered. Seasonal hazard maps for different stranding times and seasonal risk maps were then produced for the whole Sicilian coastline. The results highlight that depending on the meteo-marine conditions, particles can reach different areas of the Sicily coast, including its northern side, and illustrate how impacts can be greatly reduced through prompt implementation of mitigation strategies. [ABSTRACT FROM AUTHOR]

Abstract: The surface circulation of the Sardinian Sea (the shelf-slope region west of Sardinia, western Mediterranean sea) and the coastal upwelling were studied through the analysis of a 4-years interannual simulation performed with a hydrodynamic 3D numerical model. The model (an implementation of the Princeton Ocean Model) was forced with realistic atmospheric and oceanic fields (analyses) for the quadrennium 2008–2011. The model assimilates sea level data using a 3D-variational assimilation software. Simulated velocities were decomposed in their mean and turbulent part. Eddy kinetic energy and eddy momentum flux, able to describe synthetically in terms of kinetics the fluctuating part of the flow, have been calculated. The EOF decomposition was used to get further insight on the simulated dataset and shed light on the variability of the main dynamical features, as well as to identify and separate the coastal upwelling signature. At surface the mean circulation is characterized by a southward current flow getting closer to the coast in correspondence of the southern corner of the Island where if flows over the shelf edge. Eddy momentum flux field suggests that this southward stream is accelerated by a transfer of momentum from the eddy to the mean field in the area where it reaches maximum velocity. The presence of such a stable stream, having also a consistent fluctuating part, is argued to precondition the coastal upwelling in the southern area. The phenomenology of such a coastal upwelling along the western coast of Sardinia is then described for the first time. The upwelling, especially evident in the southern part of Sardinia, constitutes the main surface temperature signal of the modeled SST anomalies. A significant correlation was found with both wind directions and current intensity, suggesting that both mechanisms (current and wind driven upwelling) participate to precondition and enhance (respectively) upwelling. SST satellite imagery support such a pattern found in the model results. [Copyright &y& Elsevier]

Abstract: Oil spill is a serious threat for all marine and coastal environments. This is even more true for areas having high environmental, social and/or touristic value. A serious and scientifically rigorous identification of the hazard and risk related to oil slicks is becoming mandatory, in order to reduce or mitigate the impact of oil dispersal at sea and its stranding. A new model based method for evaluating hazard of oil slicks contact with shorelines of the Archipelago of La Maddalena (Strait of Bonifacio, Sardinia, Italy) has been developed and applied. The core of the methodology is a coastal 3D finite elements model, able to simulate hydrodynamics and waves of the strait of Bonifacio and, through a Lagrangian module, the physical/chemical fate of the oil at sea. In order to estimate the hazard due to oil slicks for the Archipelago and Northern Sardinia shorelines, a two-years interannual experiment has been conducted. An hazard index, given by the ratio between the oil concentration reaching each predefined coastal cell and the maximum stranded concentration, has been computed and mapped by using geostatistic tools in GIS environment. Temporal and spatial variability as well as the climatological distribution of the hazard index were therefore described: this can be an useful information for local authorities in order to efficiently manage oil slick emergencies. A significant temporal and spatial variability has been observed in the distribution of the hazard index, showing highest values for winter months, in agreement with stronger wind-induced currents. Large hazard values were found mainly along westerly exposed shorelines, as expected considering the prevalence of westerly winds blowing through the Strait. In order to assess the risk, such a hazard index can be easily combined with quali-quantitative factors of vulnerability of the coastal environment, assuming the risk is the product of hazard and vulnerability. Two of the most important factors of vulnerability have been combined with the hazard index: the shores geomorphology and the level of environmental protection (proxy for the environmental value). The southern side of Spargi Island shows the highest risk values, because of coincident presence of large hazard index values, beaches presenting last classes of geomorphological vulnerability and a moderate/high level of protection. [Copyright &y& Elsevier]

The distribution of deep-water rose shrimp (Parapenaeus longirostris , FAO 3 alpha code DPS), the main target species of demersal fisheries in the Strait of Sicily, is investigated in relation to surface parameters and biogeochemical processes. Such processes are known to influence sea bottom habitats and may be particularly relevant to the Strait of Sicily because of its relative shallowness and high surface primary production. Shrimp abundances recorded during multi-annual and seasonal trawl surveys (2004–2008) are analyzed. A GAMM and GAM model analysis is performed comparing juvenile abundances to monthly mean spatial patterns of remotely-sensed sea surface temperature (SST) and surface chlorophyll (chl), as well as their frontal structures, with a time-lag of one month, given the pelagic behavior of DPS early life stages preceding settlement. Juvenile and total shrimp abundances are also compared to the flux of particulate organic carbon (POC) to the seabed. The POC flux is computed via 1-D and 3-D models simulating sinking, re-mineralization and horizontal advection and diffusion of surface POC. The latter is derived from surface primary production maps obtained from ocean color data. Results show that the abundance of the juvenile fraction of DPS is significantly correlated with depth, distance to SST fronts and the intensity of chl fronts (correlation R 2 = 80%). Furthermore, results strongly suggest the significant role of bottom POC flux in conditioning the distribution of DPS abundance, indicating that ecological processes occurring in surface waters influence food availability near the seabed in the investigated area. • Influence of environmental parameters on deep-water rose shrimp (DPS) abundance in the Strait of Sicily (Mediterranean Sea). • DPS abundance was recorded during multi-annual and seasonal trawl surveys (2004–2008). • GAMM modelling DPS juvenile abundances in relation to surface temperature and chlorophyll and their frontal structures. • DPS abundance compared to bottom POC flux via sinking, remineralization and horizontal diffusion models. • Results show significant relationships between DPS abundance and surface frontal parameters and bottom POC flux patterns. [ABSTRACT FROM AUTHOR]

This study compiles information on the size distribution and reproductive patterns of five chondrichthyans and 10 bony species dwelling on the continental slope of the Central-Western Mediterranean (south-eastern Sardinian waters, depth 720–1890 m). The abundance of the relatively less numerous chondrichthyans was found to decrease with depth. Almost all chondrichthyan species had a long reproductive period throughout the year at all depths. In bony fishes, the upper bathymetric stratum (<1100 m) was dominated by species with continuous and seasonal (autumn-winter) spawning cycles. At intermediate and lower depths (>1100 m), continuous reproduction was the most common pattern. Both chondrichthyans and bony fishes exhibited large sizes at maturity and at first maturity (>75% and >60% of their maximum body length, respectively), supporting the hypothesis that most deep-sea fish populations are characterized by a delayed maturity, which makes them highly vulnerable to fishing pressure and over-exploitation. In some sharks, population partitioning was observed, according to life stage as a function of depth: adult/mature females occupied deeper habitats than males and juveniles. Conversely, Dipturus nidarosiensis female and male juveniles (>1100 m) were segregated from the adult/mature population, dwelling between 1000 and 1100 m. In four of the 10 bony fishes examined, we found a clear and significant predominance of females, particularly pronounced in Alepocephalus rostratus , which is clearly related to their K-reproductive strategy. The four key-selected species (Galeus melastomus , A. rostratus , Bathypterois mediterraneus and Trachyrincus scabrus), characterized by different reproductive strategies/modalities and feeding behaviours, were differently affected by depth and fluxes of organic matter (Particulate Organic Carbon concentration) from the photic zone towards the sea-bottom as a function of sex and life -stage. • The numbers and densities of chondrichthyans were lower than those of bony fishes and decreased with depth. • A continuous breeding cycle in chondrichthyans and a spawning duration increasing with depth in bony fishes were observed. • The seasonal reproduction in autumn and winter was related to POC concentration at surface. • A delayed size at maturity, in chondrichthyans >75% and in bony fishes >60% of their maximum length, was reported. • Population partitioning according to sex and life stage was showed both in chondrichthyans and bony fishes. [ABSTRACT FROM AUTHOR]