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Morpho-bathymetric data have been analyzed in order to provide new geological evidence on the Gulf of Naples, i.e., on the southern Ischia slope, on the Naples canyons and on the Capri–Sorrento slope, representing main morphological and depositional domains of the Gulf of Naples through shaded relief and slope maps constructed through multibeam bathymetric data resulting in a newly constructed digital elevation model of the bay. A slope gradient map has allowed for the identification of the main slope classes on the offshore of Naples town and their correlation with regional morpho-structural lineaments in both the offshore of Naples and Ischia. A high slope map is herein shown in order to individuate the areas potentially prone to slide. The cluster of the slope gradients distribution and the consequent re-classification process have allowed us to define six slope classes, resulting in a thematic map of the seabed morphological structures and in further detail, in a map of the structure classes of the Naples canyons. Three districts have been distinguished from high gradients on the slope map, suggesting a high geologic hazard of submarine features (southern Ischia slope, Naples canyons, southern Capri–Sorrento slope). Detailed geomorphological maps of these districts have been assembled based on the geological interpretation of morpho-bathymetry and the structure classes defined by the Bathymetric Position Index. These maps could provide a useful tool for planning and management of coastal zones in the submarine portions of the Naples Bay. [ABSTRACT FROM AUTHOR]

We present a high-resolution bathymetric map of the Gulf of Naples (Italy), which is surrounded by the two main volcanic complexes of Mt. Somma-Vesuvius and Phlegrean Fields. The morphology is obtained from swath bathymetric in a Digital Terrain Model with a 5 m grid cell size. Bathymetric data display the main seafloor morphologies with a resolution never obtained before. These morphologies include the Ammontatura and Dohrn Canyons, the Penta Palummo, Nisida, Miseno and Banco della Montagna banks, and the bathymetric features of the submerged sector of the Somma-Vesuvius volcano. Overall, a prevailing volcanic nature characterizes the seafloor morphologies located in the northern sector, while the southern one is dominated by sedimentary features. The Final Map could be useful for the evaluation of the volcano-related hazards in the area. [ABSTRACT FROM AUTHOR]

Submarine canyons are geomorphologic lineaments engraving the slope/outer shelf of continental margins. These features are often associated with significant geologic hazard when they develop close to densely populated coastal zones. The seafloor of Naples Bay is deeply cut by two incisions characterized by a dense network of gullies, namely the Dohrn and Magnaghi canyons, which develop from the shelf break of the Campania margin, down to the peripheral rise of the Eastern Tyrrhenian bathyal plain. Seismic-stratigraphic interpretation of multichannel seismic reflection profiles has shown that quaternary tectonics and recent to active volcanism have exerted a significant control on the morphological evolution and source-to sink depositional processes of the Dohrn and Magnaghi submarine canyons. The Dohrn canyon is characterized by relatively steep walls hundreds of meters high, which incise a Middle-Late Pleistocene prograding wedge, formed by clastic and volcaniclastic deposits associated with the paleo-Sarno river system during the Mid-Late Pleistocene. The formation of the Dohrn canyon predates the onset of the volcanic eruption of the Neapolitan Yellow Tuff (NYT), an ignimbrite deposit of ca. 15 ka that represents the bedrock on which the town of Napoli is built. Integrated stratigraphic analysis of high-resolution seismic profiles and marine gravity core data (C74_12) collected along the flanks of the eastern bifurcation of the head of Dohrn Canyon suggests that depositional processes along the canyon flanks are dominated by gravity flows (e.g., fine-grained turbidites, debris flows) and sediment mass transport associated with slope instability and failure. [ABSTRACT FROM AUTHOR]

The aim of the present work is to demonstrate the practical importance of a multidisciplinary approach and weighted criteria to synthesize and integrate different typologies of data (or lines of evidence, LOEs), including chemical levels in marine sediments, their bioavailability to specific indicator species, ecotoxicological effects measured through subcellular biomarkers and batteries of bioassays, and potential impacts of pollution on local benthic communities. The area of Bagnoli (Gulf of Naples, Southern Italy) was selected as a model case-study, as it is a coastal area chronically impacted by massive industrial contamination (trace metals and hydrocarbons), and dismissed decades ago without any subsequent remediation or habitat restoration. The results of each LOE were elaborated to provide specific hazard indices before their overall integration in a weight of evidence (WOE) evaluation. Levels of some trace metals and PAHs revealed a severe contamination in the entire study area. Bioavailability of hydrocarbons was evident particularly for high molecular weight PAHs, which also caused significant variations of cellular biomarkers, such as cytochrome P450 metabolization in fish, lysosomal membrane destabilization in mussels, genotoxic effects both in fish and molluscs. The results of a battery of bioassays indicated less marked responses compared to those obtained from chemical and biomarkers analyses, with acute toxicity still present in sediments close to the source of contamination. The analysis of benthic assemblages showed limited evidence of impact in the whole area, indicating a good functioning of local ecosystems at chronic contamination. Overall, the results of this study confirm the need of combining chemical and biological data, the quantitative characterization of various typologies of hazard and the importance of assessing an integrated environmental WOE risk, to orientate specific and scientifically-supported management options in industrialized areas. • Extremely high levels of some metals and PAHs occur in sediments. • HMW-PAHs are bioavailable to local sentinel species. • Biomarkers reveal subtle adverse effects of PAHs. • Ecotoxicological bioassays indicate less marked acute effects. • WOE provides an integrated assessment of environmental health status. [ABSTRACT FROM AUTHOR]