Search

We adopted a combined geophysical-stratigraphic approach to identify grain size anomalies in sediment distribution of the Bagnoli coastal brownfield site. A large industrial plant occupied this area during most of the 20th Century. We used 18 core logs to identify macroscopic variation in sediment stratigraphy, and 72 supplemental cores to mark changes between sandy- and silt-dominated intervals. The stratigraphy evidenced the presence of anomalous lens of silt within a sandy coastal sector inside the Bagnoli industrial harbour. Cores description helped us to calibrate the interpretation of 4 subbottom profiles, that we used to obtain information on geometries of silty deposits. The spatial layout of sediments revealed that silt intervals are present in the area bounded by the old industrial wharfs. We suggest that these silty sediments are likely the result of uncontrolled discharge occurred during the last century. Once calibrated, high-resolution mono-channel seismic profiles helped us to define the shape as well as the real extent and thicknesses of silty deposits, resulted to be ca. 515.000 m(2), with an overall volume of 480.000 m(3). These results are a first attempt to define the amount of polluted sediments in the area facing the Bagnoli industrial harbour.

This paper presents new bathymetric data acquired around Linosa Island, in the Pelagie Archipelago, revealing the submarine extension of the volcanic edifice, more wide and complex than previously known. The seafloor of Linosa, from the coastal area to about 1000 m depth, was mapped with multibeam systems during the ‘Linosa 2016’ and ‘BioGeoLin 2017’ surveys. A bathymetric map of the surveyed area (about 298 km2) was drawn at the original 1:30,000 scale. Overall, the submarine portions of Linosa extend on a total area of about 159 km2 and are preferentially developed in a NW-SE direction, in agreement with the regional main tectonic trend in the area. The new bathymetric data allow to recognize different sectors in the submarine extension of the volcanic edifice where constructional (volcanic) activity alternates with erosive-depositional processes affecting the submarine flanks of the island.

reserved 8 no 1. Explorations of the Mediterranean deep sea using remotely operated vehicles have shown that the sea bed hosts rich habitats, supporting high biodiversity. However, there have been only a few studies dealing with the southern part of the basin, leading to limited protection and conservation efforts in this area. 2. ThisstudyaimedtoexploretheseabedoffLinosaIsland(SicilyChannel,southern Mediterranean Sea), which is considered a ‘sentinel area’ for alien species and global environmental changes owing to its geographic position, thus deserving special attention. 3. Remotely operated vehicle surveys, carried out in 2016 and 2017, were analysed to provide the first ecological characterization of benthic assemblages at depths −19 – −384 m around Linosa Island. 4. Communitiesweredominatedbythreepriorityhabitats,amountingto39%ofthe almost 5 km of the sea floor that was surveyed. These are represented in the euphotic zone by Posidonia oceanica meadows and, at greater depth, by newly discovered dense coral forests and extended rhodolith/maërl beds. Sixteen habitat-forming species included in the Red List of the International Union for Conservation of Nature (e.g. gorgonians Eunicella cavolini and Paramuricea clavata, and black corals Antipathella subpinnata and Leiopathes glaberrima) were recorded, as well as individuals of Sargassum sp. at −100 m depth. 5. The volcanic island of Linosa represents a small, naturally preserved area, with very limited human pressure, hosting rich marine benthic biodiversity. Given the high species and habitat richness, we recommend its inclusion in the Special Protected Areas of Mediterranean Importance project (United Nations Environment Programme) and suggest a redefinition of the existing marine protected area extension. mixed Romagnoli, Beatrice; Grasselli, Ferrante; Costantini, Federica; Abbiati, Marco; Romagnoli, Claudia; Innangi, Sara; Di Martino, Gabriella; Tonielli, Renato Romagnoli, Beatrice; Grasselli, Ferrante; Costantini, Federica; Abbiati, Marco; Romagnoli, Claudia; Innangi, Sara; Di Martino, Gabriella; Tonielli, Renato

We present a new seafloor sedimentological map of Bagnoli-Coroglio SIN (Sites of National Interest) in the Gulf of Pozzuoli (Napoli), Italy, based on the analysis of the acoustic backscatter, calibrated with grain size distribution of sampled surficial marine deposits. Geophysical and ground-truthing (geological) data were acquired during a series of marine surveys designed for a seafloor characterisation aimed at remediation of the marine environment offshore the dismissed industrial area of Bagnoli. This study describes the acquisition and processing of the multibeam echo-sounder (Reson SeaBat 7125 high-resolution) backscatter data recorded during geophysical survey and illustrates the approach followed in the construction of a high-resolution seafloor map of the Bagnoli-Coroglio offshore.

The southern Tyrrhenian continental margin is the product of Pliocene-Recent back-arc extension. An area of approximately 30 km of gentle (about 1.5°) lower slope of the last glacial outer shelf sedimentary wedge in water depths of between 200 and 300 m failed between 14 and 11 ka BP. We approached the landslide by multibeam and sub-bottom profiler surveying, high-resolution multichannel seismics, and coring for stratigraphic and geotechnical purposes. With regard to a slope-stability analysis, we carried out an assessment of the stratigraphic and structural setting of the area of the Licosa landslide. This analysis revealed that the landslide detached along a marker bed that was composed of the tephra layer Y-5 (c. 39 ka). Several previously unknown geological characteristics of the area are likely to have affected the slope stability. These are the basal erosion of the slope in the Licosa Channel, a high sedimentation rate in the sedimentary wedge, earthquake shaking, the volcanic ash nature of the detachment surface, subsurface gas/fluid migration, and lateral porewater flow from the depocentre of wedge to the base of the slope along the high-permeability ash layers. A newly discovered prominent structural discontinuity is identified as the fault whose activity may have triggered the landslide.

The input flow of groundwater from the seabed to the coastal ocean, known as Submarine Groundwater Discharge (SGD), has been only recently recognized as an important component of continental margin systems. It potentially impacts physical, chemical and biological marine dynamics. Independently of its specific nature (seepage, submarine springs, etc.) or fluid chemical composition, a SGD is generally characterized by low flow rates, hence making its detection and quantification very difficult, and explaining why it has been somewhat neglected by the scientific community for a long time. Along with the growing interest for SGDs emerged the need for in-situ observations in order to characterize in details how these SGDs behave. In this work, we describe the morphology of a pockmark field, detected in the Southern Tyrrhenian Sea (Mediterranean Sea), and provide observational evidences of the presence of active submarine springs over the coastal shelf area. We describe the effect of the fluid seeps on the water column stratification close to the main plumes and in the neighbouring areas, providing quantitative estimates of the intensity of the turbulent mixing and discussing their potential impact on the seabed morphology and pockmark formation in the context of turbulent buoyant plumes analytical modelling.

Coastal ecosystems produce and store carbonate particles, which play a significant role in the carbonate dynamics of coastal areas and may contribute to the sediment budget of adjacent beaches. In the nearshore seabed of temperate zones (e.g. Mediterranean Sea and South Australia), marine biogenic carbonates are mainly produced inside seagrass meadows. This study quantifies the contribution of biogenic sediments, mainly produced in Posidonia oceanica seagrass meadows and secondarily in photophilic algal communities, to the sediment budget of a Mediterranean beach–dune system (San Giovanni beach, western Sardinia, western Mediterranean Sea). A set of geophysical, petrographic and sedimentological data was used to estimate the sediment volume and composition of the beach–dune system as a whole. The San Giovanni beach–dune system contains 3 797 000 ± 404 000 t of sediment, 83 % (3 137 000 ± 404 000 t) of which is located in the coastal wedge, 16 % (619 000 ± 88 000 t) in the dune fields and 1 % (41 000 ± 15 000 t) in the subaerial beach. The sediments are composed of mixed modern bioclastic and relict bioclastic and non-bioclastic grains from various sources. The system receives a large input of modern bioclastic grains, mainly composed of rhodophytes, molluscs and bryozoans, which derive from sediment production of present-day carbonate factories, particularly P. oceanica seagrass meadows. Radiocarbon dating of modern bioclastic grains indicated that they were produced during the last 4.37 kyr. This value was used to estimate the long-term deposition rates of modern bioclastic sediments in the various beach compartments. The total deposition rate of modern bioclastic grains is 46 000 ± 5000 t century−1, mainly deposited in the coastal wedge (39 000 ± 4 000 t century−1) and dunes (7000 ± 1000 t century−1), and 46 000 t represents ∼ 1.2 % of the total beach–dune sediment mass. Carbonate production from coastal ecosystems was estimated to be 132 000∕307 000 t century−1, 28 % (15 % ∕ 34 %) of which is transported to the beach–dune system, thus significantly contributing to the beach sediment budget. The contribution to the beach sediment budget represents a further ecosystem service, which our data can help quantify, provided by P. oceanica. The value of this sediment-supply service is in addition to the other important ecological services provided by seagrass meadows. The dependence of the beach sediment budget on carbonate production associated with coastal ecosystems has several implications for the adaptation of mixed and carbonate beaches to the loss of seagrass meadows due to local impacts and the changes expected to occur over the next few decades in coastal ecosystems following sea level rise.

Striped seagrass meadows are formed by narrow ribbons which are elevated over the seabed and separated by channels. Limited information on the genesis and development of this morphological pattern, including the adaptive responses of associated biota, is preventing holistic insight into the functioning of such protected ecosystems. This paper assessed the structural dynamics of a Posidonia oceanica striped meadow and the distribution and 3D orientation of the associated bivalve Pinna nobilis. Our analysis of the interaction between bedforms, bottom currents, and the distribution of P. nobilis revealed that the striped seascape is the result of a self-organisation process driven by feedback interactions among seagrass growth, sediment deposition, and hydrodynamics. The results suggest that the ribbon wall is the most suitable sub-habitat for this species, because it supports the highest density of P. nobilis, compared to the meadow top and bottom. Here, specimens can take advantage of the resuspension induced by hydrodynamics and open their shells towards the current, thus enhancing food intake. Therefore, our results show that self-organisation in striped seagrass meadow affects the distributional pattern of P. nobilis, providing new insights into the autoecology of this species beyond the conservation implications for its habitat.

Benthic foraminiferal assemblages from marine sediments of some selected areas off the Linosa Island (central Mediterranean) were investigated with the aim to examine their relationships with seafloor topography. Sediments were collected during different geophysical and biological surveys carried out in 2016 and 2017 around the Pelagie Islands. An integrative partial least squares approach (2B-PLS) attempted an interpretation of co-variance between seafloor morphology and benthic foraminiferal communities. We examined benthic foraminiferal assemblage characteristics (diversity and composition) in relation to seafloor topography and acoustic response (depth, backscatter, roughness, slope, aspect, topographic position index). Statistical analyses highlighted two principal groups of samples mainly distinguished by: different sampling devices (i.e. grab and box corer), depth, and sediment texture. 2B-PLS analysis suggested that roughness, slope, backscatter and depth were the main factors discriminating changes in the benthic foraminiferal assemblage beside differences in substratum type.

A previously unknown submerged volcanic field offshore western Sardinia (western Mediterranean Sea), has been identified based on swath bathymetric data collected in 2009, 2010 and 2013, and high-resolution seismic profiles collected in 2011 and 2013. About 40 conical-shaped volcanic edifices (maximum width of about 1600 m and maximum height of about 180 m) and several lava outcrops (up to 1,200 m wide) were recognized at 20 to 150 m water depth over an area of 800 km2. The volcanic edifices are mainly eruptive monogenic vents, mostly isolated with a rather distinct shape, or grouped to form a coalescent volcanic body in which single elements are often still recognizable. High-resolution seismics enabled identifying relationships between the volcanic bodies and continental margin successions. The edifices overlie a major erosional surface related to the margin exposure following the Messinian salinity crisis, and are overlain by or interbedded with an early Pliocene marine unit. This seismo-stratigraphic pattern dates the volcanic activity to the early Pliocene, in agreement with the radiometric age of the Catalano island lavas (4.7 Ma) reported in earlier studies. The morphometry of the volcanic bodies suggests that cone erosion was higher at shallow water depths. Indeed, most of the shallow edifices are strongly eroded and flattened at 125 to 130 m water depth, plausibly explained by recurrent sub-aerial exposure during Pleistocene sea-level lowstands, whereas cones in deeper water are much better preserved. Volcanic vents and lava deposits, hereafter named the Catalano volcanic field (CVF), are emplaced along lineaments corresponding to the main directions of the normal fault system, which lowered the Sinis Basin and the western Sardinia continental margin. The CVF represents a volumetrically relevant phase of the late Miocene – Quaternary anorogenic volcanic cycle of Sardinia, which is related to the first stage of the extensional tectonics affecting the island since the late Miocene.

In this work, the seabed mapping of the shallow-water areas of Lampedusa, Lampione and Linosa, belonging to the "Pelagie Islands" Marine Protected Area, is presented. Three surveys were carried out (namely "Lampedusa2015", "Linosa2016" and "BioGeoLin") to collect bathymetric and acoustic backscatter data through the use of a Reson SeaBat 7125 high-resolution multibeam system. Ground-truth data, in the form of grab samples and diver video-observations, were also collected during the surveys. Sediment samples were analyzed for grain size, while video images were analyzed and described revealing the acoustic seabed and other bio-physical characteristics. Three seabed classification maps, including sediment types and seagrass distribution, were produced using Remote Sensing Object Based Image Analysis by integrating information derived from backscatter data and bathy-morphological features, validated by ground-truth data. The seabed maps, including sediment types and habitat distribution, contribute to the knowledge of the peculiar marine ecosystem observed at the islands.

A closely spaced set of high-resolution Chirp-Sonar and Sparker profiles and swath bathymetric data was acquired in 2013 for the I-AMICA Project off the Volturno River mouth (Southern Tyrrhenian Sea) by the Istituto per l’Ambiente Marino Costiero (IAMC), National Research Council of Italy (CNR). The palaeo-topography of three key surfaces, represented by the bounding surfaces of the post-glacial lithosomes, was mapped by the interpolation of seismically detected reflectors. The morphology of the surface related to the Last Glacial Maximum (LGM) regression revealed the presence of fault linkages which defined a small-scale accommodation zone with an E–W trending interbasinal relative high. The observed set of oppositely dipping faults, NNW- and ENE-directed, locally controlled the deposition of the paralic/deltaic bodies during the post-glacial rise in sea level, as testified by their wedge-shaped geometries and shifting depocentres. The deformation may be linked to the Campi Flegrei caldera collapse following the Neapolitan Yellow Tuff (NYT) eruption and aged 15 ka BP. The relevant thickness of the Transgressive System Tract (TST) testifies to an increased sediment yield and intense reworking in coastal areas, probably driven by the high volcanoclastic supply during volcanic paroxysm, almost coeval with the post-glacial transgression. Fluid escape features linked to an E–W striking fluid front at the outer shelf suggest the presence of an hydrothermal system controlled by the predominant direction of normal to oblique Quaternary-active faults and by lithologic discontinuities across the sedimentary pile.

La Campagna Oceanografica BioGeoLin ha come obiettivo lo studio dei fondali delle Isole Pelagie mediante sistemi di indagine diretta ed indiretta. Il survey amplia il dataset acquisito dall'Istituto per l'Ambiente Marino Costiero (IAMC) del Consiglio Nazionale delle Ricerche durante la Campagna Linosa 2016, nel corso del quale sono stati individuati diversi coni vulcanici, strutture riconducibili a fenomeni erosivi e terrazzi deposizionali. Le campionature effettuate durante le precedente campagna hanno rivelato la presenza di una copertura di materiale bioclastico derivante dallo smantellamento di estese strutture coralligene, la cui presenza era confermata dalle immagini registrate mediante il ROV (Remotely Operated Vehicle)

The Malta Graben is a deep tectonic depression in the Sicily Channel, bounded by NW-SE normal faults and filled by thick Pliocene-Quaternary deposits. A previous analysis of a giant piston core (LC09) from the Malta Graben had revealed a wide range of sedimentary features (carbonate turbidites, bioturbated mud and scours), although the chronostratigraphic constraint of the stacking pattern has remained elusive. After establishing a reliable chronological framework based on seven radiocarbon dates for a shorter core from the Malta Graben (ANSIC03-735), a down-core analysis of planktonic foraminifer and coccolith abundance, stable isotopes and sediment grain size was carried out. Since the last glacial maximum, palaeoenvironmental conditions (surface fertility and deep chlorophyll maximum during the last glacial and the Younger Dryas; warm and oligotrophic water masses, with a deep nutricline and intense winter mixing during the Holocene) as well as selected calcareous plankton taxa trends and peaks seem to be similar to those reported for other central and western Mediterranean sites, possibly in spite of a unique response of these areas to late Quaternary climatic fluctuations. Four distinct layers, each tens of centimetres thick, are barren of foraminifers but not of coccoliths. Morphobathymetric data as well as new high-resolution and high-penetration seismic profiles show that prolonged contouritic activity has persisted on the western side of the Malta Graben. It is thus likely that layers barren of foraminifers are due to the overflow of fine-grained (clayey) material beyond drift channel dikes.

In this paper we present the seabed maps of the shallow-water areas of Lampedusa and Linosa, belonging to the Pelagie Islands Marine Protected Area. Two surveys were carried out (“Lampedusa 2015” and “Linosa 2016”) to collect bathymetric and acoustic backscatter data through the use of a Reson SeaBat 7125 high-resolution multibeam system. Ground-truth data, in the form of grab samples and diver video-observations, were also collected during both surveys. Sediment samples were analyzed for grain size, while video images were analyzed and described revealing the acoustic seabed and other bio-physical characteristics. A map of seabed classification, including sediment types and seagrass distribution, was produced using the tool Remote Sensing Object Based Image Analysis (RSOBIA) by integrating information derived from backscatter data and bathy-morphological features, validated by ground-truth data. This allows to create a first seabed maps (i.e. benthoscape classification), of Lampedusa and Linosa, at scale 1:20 000 and 1:32 000, respectively, that will be checked and implemented through further surveys. The results point out a very rich and largely variable marine ecosystem on the seabed surrounding the two islands, with the occurrence of priority habitats, and will be of support for a more comprehensive maritime spatial planning of the Marine Protected Area.

Acoustic methods for seafloor mapping have been widely developed over the last decades. In particular, the development of swath bathymetry has allowed the creation of detailed maps of seabed topography and acoustic backscatter data; these data have been used to infer sediment and habitat types. In this paper the capability of Multi-Beam Echo Sounder (MBES) system data to distinguish different seabed types in a site in the Tyrrhenian Sea (Mediterranean) is evaluated; dataset used includes bathymetric data and backscatter intensity, with the support of sediment samples and scuba investigations. The Reson SeaBat 8125 MBES system provides bathymetric and backscatter data. The backscatter data are stored both as Sidescan-like data (intensity values produced by an averaging process) and Snippet data (a time-series of intensity values for each beam). The processing of these acoustic data belongs to a relatively new field of research: the aim of this paper is to show two different processing approaches, and discuss the produced output. The mosaic of images from the Sidescan-like and Snippet data are statistically analyzed, in order to highlight the resolution of the Snippet when dealing with acoustic facies and the correlation existing between granulometric features and the recognized facies. In conclusion, even if no signal appears to be better than the other, it is evident that both Sidescan-like and Snippet data are complementary to a correct interpretation of the seafloor features and can produce a highly detailed acoustic mosaic useful for several scientific areas, including habitat mapping. © 2014 Elsevier Ltd. All rights reserved.

Il presente documento descrive le attività svolte da ISMAR Napoli del CNR per la realizzazione della carta dei fondali dell'Isola di Linosa in relazione alla convenzione "Realizzazione di Attività di ricerca e Monitoraggio nell'Area Marina Protetta Isole Pelagie" - Prot. n° 0013232 del 28/12/2015, stipulata con l'Area Marina Protetta e il Comune di Lampedusa e Linosa.

Il presente documento descrive le attività svolte durante la Campagna Oceanografica "Linosa" dall'Istituto per l'Ambiente Marino Costiero IAMC-CNR di Napoli relativo alla Convenzione per la "Realizzazione di Attività di Ricerca e Monitoraggio nell'Area Marina Protetta "Isole Pelagie" (Prot. N° 0013232 del 28/12/2015)" tra il Comune di Lampedusa e Linosa, Ente Gestore dell'Area Marina Protetta - AMP "Isole Pelagie", e l'IAMC di Napoli. La Campagna Oceanografica "Linosa" è finalizzata allo studio degli habitat prioritari dell'isola di Linosa, ed in particolare alla fascia costiera in cui è distribuita la prateria a Posidonia oceanica. A tale scopo sono state effettuate acquisizioni morfo-batimetriche con ecoscandaglio multifascio (multibeam) tra i 10 e gli 900 metri di profondità, acquisizioni di sismica leggera con subbotom chirp profiler e sistema sparker; come verità mare, sono state effettuate sia campionature di fondo con benna Van Veen che transetti video con sistema ROV (Remotely Operated underwater Vehicle).

The submerged sill in the Strait of Messina, which is located today at a minimum depth of 81 m below sea level (bsl), represents the only land connection between Sicily and mainland Italy (and thus Europe) during the last lowstand when the sea level locally stood at about 126 m bsl. Today, the sea crossing to Sicily, although it is less than 4 km at the narrowest point, faces hazardous sea conditions, made famous by the myth of Scylla and Charybdis. Through a multidisciplinary research project, we document the timing and mode of emergence of this land connection during the last 40 kyr. The integrated analysis takes into consideration morphobathymetric and lithological data, and relative sea-level change (both isostatic and tectonic), resulting in the hypothesis that a continental land bridge lasted for at least 500 years between 21.5 and 20 cal ka BP. The emergence may have occurred over an even longer time span if one allows for seafloor erosion by marine currents that have lowered the seabed since the Last Glacial Maximum (LGM). Modelling of palaeotidal velocities shows that sea crossings when sea level was lower than present would have faced even stronger and more hazardous sea currents than today, supporting the hypothesis that earliest human entry into Sicily most probably took place on foot during the period when the sill emerged as dry land. This hypothesis is compared with an analysis of Pleistocene vertebrate faunas in Sicily and mainland Italy, including a new radiocarbon date on bone collagen of an Equus hydruntinus specimen from Grotta di San Teodoro (23-21 cal ka BP), the dispersal abilities of the various animal species involved, particularly their swimming abilities, and the Palaeolithic archaeological record, all of which support the hypothesis of a relatively late land-based colonization of Sicily by Homo sapiens. © The Geological Society of London 2016.

The Multi-Beam Echo Sounder (MBES) is a tool that allows getting information about bathymetric, morphological and compositional characteristics of the seabed surface. Although this is still one of the most important features in hydrography, MBES can now also discriminate the acoustic imaging of the water mass by recording sampled reflectivity measurements along each beam. In this paper, two MBES, namely the Kongsberg Simrad EM3002D (300 kHz) and the Reson Seabed8125-H (455 kHz), which are generally employed to study seafloor characteristics, have been used for the identification of fish schools in the water column at very high resolution. In particular, a methodology to identify and analyse fish schools through the Water Column Backscatter (WCB) is presented. This methodology made it possible to obtain a wide variety of fish schools shape in 3-D (in our case, anchovies and sardines), which allowed a first study on the ecological behaviour of the schools according to their shape. All data were collected along with Kongsberg Simrad EK60 scientific echo sounder, allowing also a comparison of different approaches to fish schools identification. The data presented in this paper were collected during two oceanographic surveys within the project MEDIAS (MEDiteranean International Acoustic Survey), Ancheva 2010 and Ancheva 2011. Beyond the mere visualization of school shapes, we also attempted to gain numerical values of the school volumes and to realize a more detailed study of anchovies and sardines school shapes. In line with the current literature, this study showed that there are three main factors influencing the shape of a school, namely the depth of the bottom, the time of the day when data are acquired and the density of individuals in the investigated area.

We present a seabed map around Lampedusa, the largest island of the Pelagie Islands Marine Protected Area (Italy, western Mediterranean). The seafloor was mapped using bathymetry and backscatter multibeam systems along with an underwater camera for direct observations and ground truthing, from the coastal area to about 50 m depth. The map was produced to monitor the present-day distribution of the Posidonia oceanica meadows around the Island. P. oceanica is the most important endemic seagrass species of the Mediterranean Sea and it can form meadows or beds extending from the surface to 40–45 m depth. These meadows provide habitat for a large marine community, thus increasing biodiversity of the coastal zone, stabilizing sediments and reducing coastline erosion. The seagrass meadows are susceptible to regression in response to specific impacts, thus their presence and abundance is an indicator of the overall environmental quality of the coastal zone. Recently, within the Marine Strategy Framework Directive (2008/56/EC), P. oceanica has been selected as an indicator of the Good Environmental Status for marine areas. Consequently, the Pelagie Islands Marine Protected Area launched a project to assess the conservation status and map the distribution of P. oceanica meadows. The resulting 1:15,000 scale map includes information about the Mediterranean seagrass and the distribution of five acoustic facies reflecting hard lithologies and soft substrates. The Lampedusa seabed map provides new information, which contributes to the development of a detailed benthic habitat map and a more comprehensive maritime spatial planning of this Marine Protected Area.

The Bulgheria canyon-fan system in the eastern Tyrrhenian Sea displays well-developed, small-scale, fluvial- like features and has formed alongside the northern slope of the Sapri peri-Tyrrhenian basin. This study reveals, for the first time, the morphology and course of the present-day system as well as the buried elements based on a Digital Terrain Model and high-resolution seismic profiles interpretation. Two adjacent canyons (Infreschi and Luna) originate in the Cilento outer shelf at a short distance from each other and feed an intraslope basin fan through two main sub-parallel channels that run about 12 and 8 km, respectively. Channel and levee development seems to be controlled primarily by the local slope gradient and by Coriolis forces that induce a faster vertical growth of the right-side features, as is often observed in the Northern Hemisphere. Centrifugal forces, on the other hand, have induced episodic flow-stripping at the meander loops and bends, causing local destruction of the main channel levees rather than new levee growth at the outer bends. Overbank deposits are associated with overspill turbidite deposition in the mid fan where a topographic constraint occurs, whereas large-sediment, low-angle wave fields are mainly developed on the outer fan. Buried features and relict morphologies suggest that the Infreschi channel experienced at least two phases of re-incision since the final stages of the middle Pleistocene. Local re-adjustment of outer lobe growth due to channel avulsion and meander abandonment is possibly a consequence of relative baselevel fluctuations. The sedimentary record of the mid and outer fan includes outrun mass wasting deposits from extensive failures of the Sapri slope. Indeed, a marked scar is present on the eastern side of the modern outer lobe that indicates the persistency of mass flow passages up to recent times. In addition to the environmental factors that are currently considered to cause canyon formation on the shelf margin, this study proposes the possibility that the head canyon branch close to the mainland was incised by massive and persistent underground freshwater flow from the adjacent aquifer when the sea-level was lower than at present.

The use of data, including bathymetry, backscatter intensity and the angular response of backscatter intensity, collected using multibeam sonar (MBS) systems to recognise seabed types was evaluated in the inner shelf of central western Sardinia (western Mediterranean sea), a site characterised by a complex seabed including sandy and gravelly sediments, Posidonia oceanica seagrass beds growing on hardgrounds (i.e. biogenic carbonates) and sedimentary substrates. A MBS survey was carried out in order to collect bathymetric and acoustic backscatter data. Ground-truth data in the form of grab samples and diver observations were collected at 57 stations, 41 of which were in non-vegetated sedimentary substrate and 16 of which were in P. oceanica beds. Sediment samples were analysed for grain size. Statistical comparison between MBS backscatter and grain size data showed that backscatter intensity is strongly affected by sediment grain size, being directly correlated to the weight percent of the coarse fraction (1–16 mm) and inversely correlated to weight percent of the finer sediments (0.016–0.5 mm). Factor analysis of grain size and acoustic data identified three sedimentary facies: sandy gravels (SG), gravelly sands (GS) and slightly gravelly muddy sands (SGMS). Each facies showed different acoustic responses in terms of backscatter intensity and shape of the angular response curves. Differences in backscatter intensity among five seabed types, including the three sediment types identified by factor analysis and P. oceanica beds, growing on hardgrounds and sedimentary substrates, were tested by analysis of variance. P. oceanica on hardgrounds, P. oceanica on sedimentary substrates and GS exhibited values of relative backscatter intensity within the same range and, consequently, it was not possible to distinguish Posidonia beds and gravelly sands only on the basis of backscatter data. The similarity of backscatter intensity from P. oceanica growing on different substrates suggests that the acoustic response is mainly linked to the leaf canopy rather than the substrate it is growing on. A map of seabed classification, including sediment types and seagrass distribution was produced through a combination of information derived from backscatter data and morphological features derived from multibeam bathymetry, which were validated by ground-truth data.

The fan mussel Pinna nobilis is the largest bivalve of the Mediterranean Sea, declared protected since 1992. It is a sessile suspension feeder endemic of this basin which lives mainly on soft sediments colonized by seagrass meadows. This study considers a population living within a Posidonia oceanica bed in the Gulf of Oristano (W Sardinia, Italy), a site included within a Marine Protected Area and in two Sites of Community Importance. Based on field surveys conducted in 2007, 2009 and 2014 differences in density, size, and shell burial level of P. nobilis were investigated in relation to meadow's distribution and characteristics. Moreover, the spatial differences in density and orientation of P. nobilis were related to hydrological features. P. nobilis showed a mean density of 4.06±1.13 ind./100 m2 and a significant increase in population size was observed between 2009 and 2014. A high-resolution multibeam survey revealed that the P. oceanica bed was characterized by a striped structure. Toward the inner sheltered sector of Gulf, the meadow became hill-shaped. A comparison between meadow structure and P. nobilis distribution showed that specimens are mainly located at the edge of the channels within the striped meadow, whereas the edge effect resulted less noticeable within the hill-shaped meadow. The compactness of the seabed influences the shell stability: the burial level decreased with the increasing of fine sediments. Bottom current direction and speed are the main factors influencing shell orientation, whereas wave action is negligible. Where bottom current speed exceeded 0.07 m/s specimens resulted in line with the prevalent current direction with the ventral side exposed to incoming flow. These features suggest that feeding strategy is an important factor in determining shell orientation, possibly in addition to drag. Food availability could be the driving force in determining the patchiness distribution of P. nobilis population with higher values in those sites close to the mouth of the lagoons, in sedimentation area or in the meadow channels where the water flow is conveyed. These findings contribute to increase the knowledge on the P. nobilis-P. oceanica association and provide useful information for improving conservation measures.

Multibeam echosounder data collected along the shelf of the western Sardinia margin (western Mediterranean Sea) revealed the occurrence of isolated dunes at a water depth of 35-40. m, linear and crescent-shaped sorted bedforms in the depth range of 43-70. m and crescent and irregular-shaped dunes at deeper sectors of the shelf, at a 73-87. m depth range.The morphodynamics of the seabed was analyzed by coupling multibeam backscatter data calibrated with ground truth sediment samples. The linear and crescent-shaped sorted bedforms in the depth range of 43-70. m are formed by a sequence of slight depressions characterized by coarse-grained sediments which alternated with elongated bodies, composed of finer sand, spaced ten to hundred meters apart and . 70. m, wave energy is not strong enough to transport sediments and mud deposition prevails.We proposed an evolutionary model of the formation of prograding wedges and sorted bedforms off the western Sardinia shelf during the last sea-level rise. The landward migration of the shoreline subsequent to pulses of sea-level rise caused the deposition of prograding sandy wedges at different depths. Based on the present-day depth distribution, we can infer that the formation of persistent sorted bedforms over the edges of the terraces started after the sea level rose to a depth of 40. m over the seafloor where these bedforms occur.

We present a seafloor map of the summit of Palinuro Seamount, an E–W elongated volcanic ridge located in the Eastern Tyrrhenian Sea. The seafloor was mapped using multibeam backscatter and seafloor samples collected between 80 and 1000 m below the sea level. The high-resolution imaging of the Palinuro seafloor was obtained by merging a Digital Terrain Model with a 2.5 m-sized grid and a backscatter mosaic with 2.5 m pixel. The resulting 1:20,000 scale map includes six main facies recognized based on their backscatter properties. These six facies reflect different lithologies. The Palinuro seafloor map represents a useful tool for morphological and geological studies of the Palinuro volcanic ridge.

The morphodynamic evolution, during Holocene, of a wave dominated, starved shelf is presented This shelf sector is characterized by the occurrence of wide bedrock outcrops, transgressive sedimentary bodies formed by submerged depositional terraces (SDT) associated to sorted bedforms and drowned barrier-lagoon systems (BLS). The formation of transgressive depositional bodies was first controlled by the inherited topography, which influenced the accommodation space with the subsequent formation of depositional terraces, barriers and back-barrier lagoonal-deltaic deposits. This wave-dominate shelf shows a rapid adaptation to sea-level rise, with the formation of coastal morphosedimentary features over a short time periods. The STD where formed in a time range of 2 ka and the BLS in a time range of 1 ka, with a sea level rise rate in the order of 10-15 mm y-1.

L'Area Marina Protetta delle Isole Pelagie svolge, fra le sue attività, il monitoraggio di specie di grande interesse per la biodiversità. In questo progetto, oltre ad alcune nuove metodologie per la caratterizzazione biologica dei fondali, l'AMP ha inserito una valutazione dello stato di conservazione della prateria a Posidonia oceanica che rappresenta un'area di interesse biologico notevole. Per effettuare il monitoraggio di questo settore di fondale, oltre ad un'analisi lineare in situ con una valutazione dello stato di conservazione, si è deciso di utilizzare le tecnologie geofisiche che permettono una ricostruzione areale di queste bio-facies. Il Laboratorio di acquisizione e processing di dati Multibeam della sede di Napoli ha quindi messo a disposizione il suo expertise per realizzare questa valutazione attraverso indagini indirette ed osservazioni dirette puntuali. Il dataset acquisito permette una valutazione dello stato di sviluppo attuale della prateria a Posidonia o., ed il confronto con i dati pregressi in possesso dell'AMP.

The morphology and stratigraphic features of a well-preserved drowned barrier system, located on the western coast of Sardinia (Mediterranean Sea), are presented here. The barriers were mapped using a multibeam echosounder. The Digital Terrain Model of the seabed revealed five sub-parallel barriers in a depth range of 18-37. m, with a distance of ~. 300. m between each single barrier. Direct inspection by scuba diving, revealed that the barriers consist of beachrocks, topped by seagrass meadows growing on a biogenic hardground. The inner-most barrier is limited landward by a steep cliff, 10. m high, bordering the back-barrier area. About 200. km of seismic lines were collected along the barrier system using a 0.4-1.0. kJ sparker source and a 3.5. kHz Chirp Subbottom profiler. The seismic data, calibrated with vibrocores, allowed us to recognize the subaerial topographic surface of the last glacial maximum as well as several seismic units interpreted as the Pliocene marine sediments, the pre-Holocene deposits and the Holocene barrier-lagoon complex composed of shoreface, barrier, lagoonal/deltaic and beach deposits.Despite the relatively high seabed gradient (0.3°-0.4°) and the relatively low rate of sea-level rise (10-15mmy-1), the barriers were well preserved due to the early diagenetic processes which led to a rapid cementation with the formation of beachrocks, and the subsequent overstepping with the rise of the sea level. The development of the overstepping barrier system is strictly related to the antecedent subaerial topography which is, in turn, related to the tectonic setting of the area. The Pliocene seismic unit was lowered by a direct fault at the entrance of the gulf forming a depression filled by sediments. The overstepping barrier system developed following the increase of the seabed gradient and was limited landward by the above-mentioned depression which increased the accommodation space. Following the sea-level rise and the barrier formation, this depression was filled by lagoonal sediments, washover fans and sediments coming from the rivers.The age model of barrier evolution, based on previous sea-level-rise curves during the Holocene, supported by radiocarbon data, highlighted that the whole system evolved over a time period of 1. ka; while the time elapsed from this formation to the drowning of single barriers was estimated to be in the order of magnitude of centuries.Scenarios of short-term evolution of modern barrier-lagoon systems of the adjacent coastal sector, under conditions of accelerated sea-level rise, according to Church et al. (2013) (2013 IPCC report) and Rahmstorf (2007) projections, were elaborated. The study of this ancient analogue suggests that the processes of adaptation of coastal systems to the rising sea level would require times evaluable from centuries to millennia. © 2015 Elsevier B.V.

IntroductionIn the Horseshoe chain, mainly com-prising volcanic seamounts, the Gor-ringe Bank (36 N, 11 W; hereafterreferred to as GB) is an exception,because it consists of suboceanic man-tle peridotites and gabbros. The otherpeculiarity of this seamount is thegreat bathymetric gradient betweenthe summit of the bank, at )30 m,and the surrounding abyssal plains,Tagus and Horseshoe at )5000 m(Fig. 1). The GB is a N60 -trendingridge, 200 km long and 80 km wide,with two summits, the Gettysburg inthe south-west and the Ormonde inthe north-east (Beauzart et al., 1979).The two summits, separated by a deep(800 m) saddle, consist of igneousrock outcrops with very thin or absentsedimentary cover.The first exploration of the GB wasmade by the Glomar Challenger in1970 (120 DSDP sites; Ryan et al.,1973). This and some subsequentexplorations with manned submersi-bles along the flanks of the ridge in the0–3000 m bathymetric range (Auzen-de et al., 1978; Lagabrielle andAuzende, 1982), and more recently atgreater depths (Girardeau et al.,1998), have indicated that the GBrepresents a remarkable example of aseamount comprising lower oceaniccrust⁄upper mantle rocks.In December 2002 to January 2003duringtheGorringe_2003 expedition,on board R⁄V Urania (NationalResearch Council, Italy), swath bathy-metry, seismo-magnetic survey, exten-sive bottom samplings and some ROV(remotely operating vehicle) dives overthe top of the GB were carried out (deAlteriis et al., 2004). A further aim ofthe cruise was to study the bioclasticsediments recorded during previousexpeditions (Auzende et al., 1978; Gir-ardeau et al., 1998) at shallow depths.The location and physiography of theGB guaranteed that these sedimentswere totally autochthonous anduncontaminated by other sources.The only previous analyses availablefromthesesedimentswereprovidedbyAvila and Malaquias (2003).Geological and stratigraphic resultsThe multibeam and geophysical sur-vey, extended to 500 m depth overboth summits, revealed that Gettys-burg seamount has an almost subcir-cular summit, elongated N–S for8–10 km. The shelf area is somewhatconvex from )60 to )175 m. At thecentre of the summit the igneousbasement crops out between depthsof )29 and )60 m. The rocky outcropconsists of roughly N–S-trending rid-ges consisting of foliated serpentinitesand gabbros completely surroundedby a blanket of bioclastic sands andgravels down to )140 m, where a cleardepositional shelf break appears(Figs 1 and 2). Pockets of these sandsare also hosted in the inter ridgedepressions. Sands consist of skeletalcalcareous algae, forams, bryozoansand molluscs. The heterozoan associ-ation (James, 1997) is dominated byForamol facies (Lees and Buller,1972) over the entire shelf area withthe typical absence of allochthonousnon-skeletal grains. Some exhumedEarly Pliocene foraminifers, Globoro-talia margaritae (Bolli & Bermudez),are also present in the fine fraction.Lithoclasts are generally rare andmainly consist of serpentinized ultra-mafics and gabbros.Samplings and ROV observationsconfirm that modern bioclastic mate-rial is continually produced by thebenthic ecosystem that characterizesthis and other Atlantic seamountsas temperate carbonate factories.Detailed bathymetry and subbottomprofiling allow us to establish that theaverage thickness of this material doesnot exceed a few metres in the shelfareas and in the pockets. TheseABSTRACT

High resolution swath bathymetry of shallow water (< 200 m) oceanic seamounts is a relatively rare issue. During the recent Gorringe_2003 cruise over the Gorringe Bank (Eastern Atlantic) we collected multibeam bathymetry on the bank’s two shallow summits, Gettysburg and Ormonde in the –25/–400m depth range at a resolution rarely achieved over an oceanic seamount. We also carried out bottom samplings and ROV dives in the same bathymetric interval. The acquisition parameters and the characteristics of the echosounder employed allowed to generate a Digital Terrain Model (DTM) with metric spatial resolution upto 75–100 m depths. To ensure proper tidal corrections a tide-gauge was deployed at sea-bottom during the survey. DTM reveals for the Gettysburg Seamount an almost perfectly circular summit resulting from the blanket of bioclastic sediments over an igneous ‘core’ consisting of sheared and foliated serpentinites. The core is dissecated by N 10° W trending ridges elevating some tens of metres and filled in between by bioclastic sands. Both foliation and ridge patterns seem related to primary igneous fabric rather than later structural deformation. The overall circular shape confirms the origin of the seamount as a mantle serpentinite diapir in analogy with similar, but subduction-related, circular seamounts observed in the Bonin Trench (western Pacific). In contrast the Ormonde elongated summit follows the regional tectonic trend with a N 60° E active (seismogenic?) fault on its southeastern flank. Its basement morphology corresponds to the outcrops of igneous rocks chiefly consisting of gabbros, volcanic rocks and dyke intrusions. On both seamounts topographic profiles show that the ‘shelf’ area is somewhat convex rather than flat like that of ‘Pacific type’ guyots and is bordered by a depositional, locally erosional shelf break, located between –170 and –130 m. Various terraced surfaces and some geological evidence confirm previous observations and indicate relative sea-level oscillations with partial emersion of the two summits that seem occurred during the last glacial cycle (past 120 ka).

The results of the geological and geomorphological survey of the Naples Bay carried out by the IAMC-CNR Institute of Naples on behalf of the National Geological Survey of Italy (now ISPRA) and by the Geological Survey of the Campania Region are here presented. The geological maps produced through the marine geological survey (at scales varying from 1:50.000 to 1:10.000) are: n. 446-447 "Napoli", n. 464 "Ischia", n. 465 "Procida", n. 466 "Sorrento nord" and n. 484 "Capri". The geological survey consisted in the acquisition of multibeam and single-beam bathymetric data, Sidescan Sonar acoustic imagery, reflection seismics, sea bottom samples and piston cores. A detailed marine geological survey, at the scale 1:10.000, has also been merged with underwater geological survey (up to the - 30 m of water depth), based on a direct sampling of both rocky outcrops and mobile sea bottoms, allowing to draw key geologic and morpho-stratigraphic sections. The physiographic domains, representative of tectono-sedimentary and/or volcanic processes, include the continental shelf, the abrasional or depositional marine platforms, often in correspondence to coastal cliffs, the relic or preserved morphologies of monogenic volcanic edifices, the hummocky chaotic deposits, accumulated as a consequence of gravity instability processes. Moreover, the continental slope appears deeply incised by canyons evolving downslope to tributary channels. The CARG-MARE Project has evidenced the regional geological structure of the Naples Bay, located along the western margin of the southern Apenninic chain and representing a Pleistocenic half-graben, similarly to the peri-tyrrhenian basins, which form the seaward prolongation of the coastal plains of the Campania Region (Campania Plain and Volturno Plain).

The effects of incorrect sound speed values on multibeam survey accuracy are well-documented. Typical artifacts appear in the logged data such as "ripples" when the Sound Velocity Profile (SVP) is overestimated (frowning) or undervalued (smiling). These events can be caused by a fresh-water runoff or upwelling; it is possible to re-compute bathymetric data in post-processing by generating an equivalent SVP that can be applied to the raw data. During the last ten years the Coastal Marine Environment Institute of the National Research Council (I.A.M.C. - C.N.R, Naples, Italy) has developed national and regional research programs on morpho-bathymetric mapping. The Regional Geological Cartography (CARG) Project was carried out to study the Campanian continental shelf, from 3 meters to 200 meters depth. Multibeam data collected in shallow water during the CARG were often suffering from smiling or frowning because of the fresh water run-off produced by rivers along the Campanian coasts. In this paper the method used to correct these data and the use of these fixes for tracking unreported underwater springs are described.

We present a high resolution DTM of the Palinuro Seamount (PS, Tyrrhenian Sea, Italy) resulting from the processing of multibeam swath bathymetry records acquired during the second leg of the "Aeolian 2007" cruise. PS consists of several superimposed volcanoes aligned along a N100°E strike and measures 55 × 25 km. The western and the central sectors result from the coalescence of collapse structures (calderas) with younger volcanic cones. The eastern sector reveals a more complex and articulated structure. In the central sector, a volcanic crater with a well-preserved rim not obliterated by erosional events suggests a volcanological rejuvenation of this sector. The presence of flat surfaces on the top of the seamount may be due to the formation of marine terraces during the last sea-level lowering. Lateral collapses on the northern and southern flanks of the seamount are probably related to slope instability, as suggested by the presence of steep slopes (25-40°). The main fault affecting PS strikes N65°E and shows a right lateral component of movement. E-W and N10°E striking faults are also present. Assuming that the N100°E deep-seated fault, which is responsible for the emplacement of PS, moved with sinistral slips, we interpret the N65°E and the N10°E faults as right-lateral (second order) shear and left-lateral (third order) shear, respectively. Due to the particular location of the Palinuro Seamount, the data presented here allow us to better understand the volcanism and the geodynamic processes of the Tyrrhenian Sea. © 2009 Elsevier B.V. All rights reserved.

A quantitative analysis of planktonic foraminifera, coupled with petrophysical and paleomagnetic measurements and 14 C-AMS calibrations, was carried out on a deep core recovered in the Sardinia Channel (Western Mediterranean Sea), during the CIESM Sub2 survey, providing an integrated stratigraphic time-framework over the last 80 kyr. Significant changes in the quantitative distribution of planktonic foraminifera allowed the identification of several eco-bioevents useful to accurately mark the boundaries of the eco-biozones widely recognized in the Western Mediterranean records and used for large-scale correlations. Namely, 10 eco-biozones were identified based on the relative abundance of selected climate-sensitive planktonic foraminiferal species. Sixteen codified eco-bioevents were correlated with Alboran Sea planktonic foraminiferal data and several climatic global events (Sapropel S1, Younger Dryas, Greenland Isotope Interstadial 1, Greenland Isotope Stadial 2, Heinrich event H1–H6) were recognized. The eco-bioevents together with the 14 C-AMS calibrations allowed us to define an accurate age model, spanning between 2 and 83 kyr. The reliability of the age model was confirmed by comparing the colour reflectance (550 nm%) data of the studied record with the astronomically tuned record from the Ionian Sea (ODP-Site 964). A mean sedimentation rate of about 7 cm/kyr included three turbidite event beds that were chronologically constrained within the relative low stand and regressive sea-level phases of MIS 4 and 3. The deep-sea sedimentary record includes a distinct tephra occurring at the base of the core that dates 78 ka cal. BP. The paleomagnetic data provide a well-defined record of the characteristic remanent magnetization that may be used to reconstruct the geomagnetic paleosecular variation for the Mediterranean back to 83 kyr.