We present a major, trace and rare earth element characterization of single glass shards from fif... more We present a major, trace and rare earth element characterization of single glass shards from fifteen tephra layers found in the astronomically-tuned KC01B deep-sea core (Ionian Sea, Central Mediterranean-36 15.25 0 N, 17 34.44 0 E, 3642 m water depth). KC01B is considered a reference core for the Mediterranean area since it provides a new reliable astronomical tuned timescale for the last 1.112 My (Lourens, 2004). The studied deposits punctuate the marine record in a time span ranging from ca 16 ka to ca 191 ka B.P. encompassing the climatic zones Y, X, W and V. They are related to volcanic activity of the Campania Plain, Aeolian Islands, Mt. Etna and Pantelleria Island. Along with major main markers of the Central Mediterranean area such as Y-1, Y-5, and X-6, astronomically dated at 16.7 ka, 39.1 ka, and 110.5 ka, respectively, the succession contains a number of well preserved deposits which can represent useful inter-archive instruments of correlation. The Campania Plain, in particular, sourced at least nine compositionally homogeneous tephra layers prior to the Campanian Ignimbrite event. The data obtained in this work provide a new detailed analytical reference database for Ionian Sea tephrochronology and for proximal-distal correlation studies. They may help to unravel from the marine record the history of poorly known or unknown explosive activity on land since the middle Pleistocene along with chemical composition, size and dispersal of the products.
Journal of Volcanology and Geothermal Research, 2014
We present the first results of a multidisciplinary research aimed at the detection and mapping o... more We present the first results of a multidisciplinary research aimed at the detection and mapping of Active Fluid Vents (AFVs) at the seafloor of the Naples Bay, Italy. This segment of the Campania continental margin is characterised by severe Quaternary extension and intense volcanism at Ischia and Procida islands, the Campi Flegrei and Somma-Vesuvius volcanic complexes. High resolution hydroacoustic profilers were used to identify and localize fluid emission from the seafloor. ROV direct observation showed that each emission centre is generally composed by the coalescence of several emitting points. CTD probes showed that there are no significant gradients in temperature profiles. The results of this study include the detection and mapping of 54 fluid emission points all located in the −71/−158 m depth range, and spatially distributed into four main clusters. Three of the described clusters are located along the margin of a complex, toe-shaped seafloor morphology southwest of the Somma-Vesuvius, representing the shallow expression of partly buried, coalesced depositional features (namely, two flank collapses and one pyroclastic flow) associated with the Late Pleistocene activity of the volcano. The fourth AFV cluster was detected at the morphological -high, located about 8 km south of Naples (Banco della Montagna), represented by a field of volcaniclastic diapirs composed of massive pumiceous deposits originated from the Campi Flegrei intruding rising through the latest Quaternary-Holocene marine deposits. Our study suggests that the occurrence of AFV in this area could be genetically linked to the interaction between volcanic related seafloor morphologies and the main, NE striking faults present in the area, i.e. the Magnaghi-Sebeto line and the Vesuvian fault.
A comparative study was performed to identify differences in the amino acid composition of the ey... more A comparative study was performed to identify differences in the amino acid composition of the eyes from zebrafish (Danio rerio) and sardine (Sardina pilchardus) larvae and their link to the environmental adaption of the species. Amino acids in the acidic hydrolysates of eyes from 11 zebrafish and 12 sardine were determined with the use of high-performance liquid chromatography involving precolumn derivatization with ortho-phthalaldehyde. Differences in the content of most amino acids were detected between zebrafish and sardine. These amino acids were aspartate, glutamate, serine, glycine, threonine, arginine, methionine, valine, phenylalanine, isoleucine, leucine and lysine. Of particular note, the percentage of methionine in zebrafish eyes was much higher than that in sardine, whereas the opposite was observed for glutamate and glycine. These results indicate that zebrafish and sardine likely have experienced differences in adaptation to environmental changes. We suggest that the amino acid composition of eyes represents a powerful tool to discriminate between species characterized by different lifestyle and inhabiting different environments.
Here we investigate mercury concentrations in the blood (HgB), urine (HgU) and human hair (HgH) o... more Here we investigate mercury concentrations in the blood (HgB), urine (HgU) and human hair (HgH) of 224 individuals from a coastal area (Eastern Sicily, SE Italy) strongly affected by Hg contamination from one of the largest chlor-alkali plants in Europe. The factors affecting the distribution of Hg and the extent of the exposure of individuals have been explored with a multidisciplinary approach. Multiple regression analyses, together with evidence of high levels of HgB (exceeding the HBMI recommended levels in 50% of cases) and HgH (exceeding the EPA reference dose in 70% of cases), primarily suggest that the consumption of local fish is the main source of Hg for humans. no. significant exposure to inorganic mercury was identified. Toxicokinetic calculations produced a provisional tolerable weekly intake (PTWI) level that, in most cases, exceeds international recommendations, particularly for residents in the studied area.
Journal of Volcanology and Geothermal Research, 2014
We present the first results of a multidisciplinary research aimed at the detection and mapping o... more We present the first results of a multidisciplinary research aimed at the detection and mapping of Active Fluid Vents (AFVs) at the seafloor of the Naples Bay, Italy. This segment of the Campania continental margin is characterised by severe Quaternary extension and intense volcanism at Ischia and Procida islands, the Campi Flegrei and Somma-Vesuvius volcanic complexes. High resolution hydroacoustic profilers were used to identify and localize fluid emission from the seafloor. ROV direct observation showed that each emission centre is generally composed by the coalescence of several emitting points. CTD probes showed that there are no significant gradients in temperature profiles. The results of this study include the detection and mapping of 54 fluid emission points all located in the −71/−158 m depth range, and spatially distributed into four main clusters. Three of the described clusters are located along the margin of a complex, toe-shaped seafloor morphology southwest of the Somma-Vesuvius, representing the shallow expression of partly buried, coalesced depositional features (namely, two flank collapses and one pyroclastic flow) associated with the Late Pleistocene activity of the volcano. The fourth AFV cluster was detected at the morphological -high, located about 8 km south of Naples (Banco della Montagna), represented by a field of volcaniclastic diapirs composed of massive pumiceous deposits originated from the Campi Flegrei intruding rising through the latest Quaternary-Holocene marine deposits. Our study suggests that the occurrence of AFV in this area could be genetically linked to the interaction between volcanic related seafloor morphologies and the main, NE striking faults present in the area, i.e. the Magnaghi-Sebeto line and the Vesuvian fault.
Sources of anthropogenic pollution were categorised by combining elemental and isotopic technique... more Sources of anthropogenic pollution were categorised by combining elemental and isotopic techniques (C/N ratios and d 13 C, d 15 N) 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 d 13 C and d 15 N 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 d 15 N values showed high sensitivity to discriminate sewage discharges (treated or untreated organic matter), clearly indicating the point of emissions. The d 13 C shows indirect capability of discriminating crude oil and petroleum products.
A number of scientific papers in the last few years singled out the influence of environmental co... more 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'.
ABSTRACT Five sperm whales (Physeter macrocephalus) stranded along the Italian coast between 2007... more ABSTRACT Five sperm whales (Physeter macrocephalus) stranded along the Italian coast between 2007 and 2009 were analysed for concentrations of trace elements in the muscle, liver, kidney, lung, heart and skin. Essential elements (Zn, Cu, Fe, Cr, As, V and Se) show ranges of variability comparable with the limited data reported in the literature on this species and a homeostatic physiological control. Very low concentrations of nonessential elements (Hg, Cd and Pb) were detected in all tissues, suggesting a minor impact of these pollutants on the sperm whale populations of the Mediterranean Sea. This finding possibly reflects the pelagic lifestyle and deep-sea cephalopod diet of this group of giant cetaceans. In addition, this finding contrasts with the high levels of nonessential elements measured in many other species of cetaceans (e.g. Stenella coeruleoalba, Tursiops truncatus) stranded along Mediterranean coasts and which reflects significant coastal anthropogenic effects. The main result of this work is the compiled dataset which provides a preliminary target for conceptual understanding of the potential effects of open marine pollution on the Mediterranean sperm whale population.
Geostatistical techniques were applied and a series of spatial indicators were calculated (occupa... more Geostatistical techniques were applied and a series of spatial indicators were calculated (occupation, aggregation, location, dispersion, spatial autocorrelation and overlap) to characterize the spatial distributions of European anchovy and sardine during summer. Two ecosystems were compared for this purpose, both located in the Mediterranean Sea: the Strait of Sicily (upwelling area) and the North Aegean Sea (continental shelf area, influenced by freshwater). Although the biomass of anchovy and sardine presented high interannual variability in both areas, the location of the centres of gravity and the main spatial patches of their populations were very similar between years. The size of the patches representing the dominant part of the abundance (80%) was mostly ecosystem- and species-specific. Occupation (area of presence) appears to be shaped by the extent of suitable habitats in each ecosystem whereas aggregation patterns (how the populations are distributed within the area of p...
A number of scientific papers in the last few years singled out the influence of environmental co... more 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'.
The Augusta basin, located in SE Sicily (southern Italy), is a semi-enclosed marine area, labelle... more The Augusta basin, located in SE Sicily (southern Italy), is a semi-enclosed marine area, labelled as a highly contaminated site. The release of mercury into the harbour seawater and its dispersion to the blue water, make the Augusta basin a potential source of anthropogenic pollution for the Mediterranean Sea. A mass balance was implemented to calculate the HgT budget in the Augusta basin. Results suggest that an average of $0.073 kmol of HgT is released, by diffusion, on a yearly basis, from sediments to the seawater, with a consequent output of 0.162 kmol y À1 to coastal and offshore waters; this makes the Augusta area an important contributor of mercury to the Mediterranean Sea. Owing to the geographical location of the Augusta basin, its outflowing shelfwaters are immediately intercepted by the surface Atlantic Ionian Stream (AIS) and mixed with the main gyres of the eastern Mediterranean Sea, thus representing a risk for the large-scale marine system.
Here we show the results of two morpho-bathymetric surveys carried out on the underwater archaeol... more Here we show the results of two morpho-bathymetric surveys carried out on the underwater archaeological area of the Pozzuoli Bay (Naples, Italy). Such area is enclosed in the Campi Flegrei active volcanic complex, where bradyseism and recent volcanic activity strongly influenced the coastline shape over the last 2 Ka. The Digital Elevation Model (DTM) of the seafloor allowed to draw the main archaeological features of the Bay, that also include the military complex of Portus Iulius and the ancient thermal and villa complex of Baianus Lacus. The extraction of archaeological features from DTM was achieved thanks to the use of a GIS-derived tool based on the profile curvature algorithm. Thus, the Villa dei Pisoni (1st Century B.C.) and the thermal complex of Secca delle Fumose were investigated by using ultra-high resolution DTMs, that show the presence of Roman pilae for the protection of coastal buildings and also the inner planimetry of the Villa dei Pisoni complex. The observation of coastal engineering structures give also the opportunity to formulate some hypothesis on the evolution of morphology and of the sedimentary pattern of the area, while depth of archaeological remains allowed a rough computation of the rate of subsidence, resulted to be 2.55 (AE0.5) mm/y for the Eastern sector (Pozzuoli) and 2.90 (AE0.5) mm/y for the western (Baia).
We present a major, trace and rare earth element characterization of single glass shards from fif... more We present a major, trace and rare earth element characterization of single glass shards from fifteen tephra layers found in the astronomically-tuned KC01B deep-sea core (Ionian Sea, Central Mediterranean-36 15.25 0 N, 17 34.44 0 E, 3642 m water depth). KC01B is considered a reference core for the Mediterranean area since it provides a new reliable astronomical tuned timescale for the last 1.112 My (Lourens, 2004). The studied deposits punctuate the marine record in a time span ranging from ca 16 ka to ca 191 ka B.P. encompassing the climatic zones Y, X, W and V. They are related to volcanic activity of the Campania Plain, Aeolian Islands, Mt. Etna and Pantelleria Island. Along with major main markers of the Central Mediterranean area such as Y-1, Y-5, and X-6, astronomically dated at 16.7 ka, 39.1 ka, and 110.5 ka, respectively, the succession contains a number of well preserved deposits which can represent useful inter-archive instruments of correlation. The Campania Plain, in particular, sourced at least nine compositionally homogeneous tephra layers prior to the Campanian Ignimbrite event. The data obtained in this work provide a new detailed analytical reference database for Ionian Sea tephrochronology and for proximal-distal correlation studies. They may help to unravel from the marine record the history of poorly known or unknown explosive activity on land since the middle Pleistocene along with chemical composition, size and dispersal of the products.
Journal of Volcanology and Geothermal Research, 2014
We present the first results of a multidisciplinary research aimed at the detection and mapping o... more We present the first results of a multidisciplinary research aimed at the detection and mapping of Active Fluid Vents (AFVs) at the seafloor of the Naples Bay, Italy. This segment of the Campania continental margin is characterised by severe Quaternary extension and intense volcanism at Ischia and Procida islands, the Campi Flegrei and Somma-Vesuvius volcanic complexes. High resolution hydroacoustic profilers were used to identify and localize fluid emission from the seafloor. ROV direct observation showed that each emission centre is generally composed by the coalescence of several emitting points. CTD probes showed that there are no significant gradients in temperature profiles. The results of this study include the detection and mapping of 54 fluid emission points all located in the −71/−158 m depth range, and spatially distributed into four main clusters. Three of the described clusters are located along the margin of a complex, toe-shaped seafloor morphology southwest of the Somma-Vesuvius, representing the shallow expression of partly buried, coalesced depositional features (namely, two flank collapses and one pyroclastic flow) associated with the Late Pleistocene activity of the volcano. The fourth AFV cluster was detected at the morphological -high, located about 8 km south of Naples (Banco della Montagna), represented by a field of volcaniclastic diapirs composed of massive pumiceous deposits originated from the Campi Flegrei intruding rising through the latest Quaternary-Holocene marine deposits. Our study suggests that the occurrence of AFV in this area could be genetically linked to the interaction between volcanic related seafloor morphologies and the main, NE striking faults present in the area, i.e. the Magnaghi-Sebeto line and the Vesuvian fault.
A comparative study was performed to identify differences in the amino acid composition of the ey... more A comparative study was performed to identify differences in the amino acid composition of the eyes from zebrafish (Danio rerio) and sardine (Sardina pilchardus) larvae and their link to the environmental adaption of the species. Amino acids in the acidic hydrolysates of eyes from 11 zebrafish and 12 sardine were determined with the use of high-performance liquid chromatography involving precolumn derivatization with ortho-phthalaldehyde. Differences in the content of most amino acids were detected between zebrafish and sardine. These amino acids were aspartate, glutamate, serine, glycine, threonine, arginine, methionine, valine, phenylalanine, isoleucine, leucine and lysine. Of particular note, the percentage of methionine in zebrafish eyes was much higher than that in sardine, whereas the opposite was observed for glutamate and glycine. These results indicate that zebrafish and sardine likely have experienced differences in adaptation to environmental changes. We suggest that the amino acid composition of eyes represents a powerful tool to discriminate between species characterized by different lifestyle and inhabiting different environments.
Here we investigate mercury concentrations in the blood (HgB), urine (HgU) and human hair (HgH) o... more Here we investigate mercury concentrations in the blood (HgB), urine (HgU) and human hair (HgH) of 224 individuals from a coastal area (Eastern Sicily, SE Italy) strongly affected by Hg contamination from one of the largest chlor-alkali plants in Europe. The factors affecting the distribution of Hg and the extent of the exposure of individuals have been explored with a multidisciplinary approach. Multiple regression analyses, together with evidence of high levels of HgB (exceeding the HBMI recommended levels in 50% of cases) and HgH (exceeding the EPA reference dose in 70% of cases), primarily suggest that the consumption of local fish is the main source of Hg for humans. no. significant exposure to inorganic mercury was identified. Toxicokinetic calculations produced a provisional tolerable weekly intake (PTWI) level that, in most cases, exceeds international recommendations, particularly for residents in the studied area.
Journal of Volcanology and Geothermal Research, 2014
We present the first results of a multidisciplinary research aimed at the detection and mapping o... more We present the first results of a multidisciplinary research aimed at the detection and mapping of Active Fluid Vents (AFVs) at the seafloor of the Naples Bay, Italy. This segment of the Campania continental margin is characterised by severe Quaternary extension and intense volcanism at Ischia and Procida islands, the Campi Flegrei and Somma-Vesuvius volcanic complexes. High resolution hydroacoustic profilers were used to identify and localize fluid emission from the seafloor. ROV direct observation showed that each emission centre is generally composed by the coalescence of several emitting points. CTD probes showed that there are no significant gradients in temperature profiles. The results of this study include the detection and mapping of 54 fluid emission points all located in the −71/−158 m depth range, and spatially distributed into four main clusters. Three of the described clusters are located along the margin of a complex, toe-shaped seafloor morphology southwest of the Somma-Vesuvius, representing the shallow expression of partly buried, coalesced depositional features (namely, two flank collapses and one pyroclastic flow) associated with the Late Pleistocene activity of the volcano. The fourth AFV cluster was detected at the morphological -high, located about 8 km south of Naples (Banco della Montagna), represented by a field of volcaniclastic diapirs composed of massive pumiceous deposits originated from the Campi Flegrei intruding rising through the latest Quaternary-Holocene marine deposits. Our study suggests that the occurrence of AFV in this area could be genetically linked to the interaction between volcanic related seafloor morphologies and the main, NE striking faults present in the area, i.e. the Magnaghi-Sebeto line and the Vesuvian fault.
Sources of anthropogenic pollution were categorised by combining elemental and isotopic technique... more Sources of anthropogenic pollution were categorised by combining elemental and isotopic techniques (C/N ratios and d 13 C, d 15 N) 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 d 13 C and d 15 N 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 d 15 N values showed high sensitivity to discriminate sewage discharges (treated or untreated organic matter), clearly indicating the point of emissions. The d 13 C shows indirect capability of discriminating crude oil and petroleum products.
A number of scientific papers in the last few years singled out the influence of environmental co... more 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'.
ABSTRACT Five sperm whales (Physeter macrocephalus) stranded along the Italian coast between 2007... more ABSTRACT Five sperm whales (Physeter macrocephalus) stranded along the Italian coast between 2007 and 2009 were analysed for concentrations of trace elements in the muscle, liver, kidney, lung, heart and skin. Essential elements (Zn, Cu, Fe, Cr, As, V and Se) show ranges of variability comparable with the limited data reported in the literature on this species and a homeostatic physiological control. Very low concentrations of nonessential elements (Hg, Cd and Pb) were detected in all tissues, suggesting a minor impact of these pollutants on the sperm whale populations of the Mediterranean Sea. This finding possibly reflects the pelagic lifestyle and deep-sea cephalopod diet of this group of giant cetaceans. In addition, this finding contrasts with the high levels of nonessential elements measured in many other species of cetaceans (e.g. Stenella coeruleoalba, Tursiops truncatus) stranded along Mediterranean coasts and which reflects significant coastal anthropogenic effects. The main result of this work is the compiled dataset which provides a preliminary target for conceptual understanding of the potential effects of open marine pollution on the Mediterranean sperm whale population.
Geostatistical techniques were applied and a series of spatial indicators were calculated (occupa... more Geostatistical techniques were applied and a series of spatial indicators were calculated (occupation, aggregation, location, dispersion, spatial autocorrelation and overlap) to characterize the spatial distributions of European anchovy and sardine during summer. Two ecosystems were compared for this purpose, both located in the Mediterranean Sea: the Strait of Sicily (upwelling area) and the North Aegean Sea (continental shelf area, influenced by freshwater). Although the biomass of anchovy and sardine presented high interannual variability in both areas, the location of the centres of gravity and the main spatial patches of their populations were very similar between years. The size of the patches representing the dominant part of the abundance (80%) was mostly ecosystem- and species-specific. Occupation (area of presence) appears to be shaped by the extent of suitable habitats in each ecosystem whereas aggregation patterns (how the populations are distributed within the area of p...
A number of scientific papers in the last few years singled out the influence of environmental co... more 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'.
The Augusta basin, located in SE Sicily (southern Italy), is a semi-enclosed marine area, labelle... more The Augusta basin, located in SE Sicily (southern Italy), is a semi-enclosed marine area, labelled as a highly contaminated site. The release of mercury into the harbour seawater and its dispersion to the blue water, make the Augusta basin a potential source of anthropogenic pollution for the Mediterranean Sea. A mass balance was implemented to calculate the HgT budget in the Augusta basin. Results suggest that an average of $0.073 kmol of HgT is released, by diffusion, on a yearly basis, from sediments to the seawater, with a consequent output of 0.162 kmol y À1 to coastal and offshore waters; this makes the Augusta area an important contributor of mercury to the Mediterranean Sea. Owing to the geographical location of the Augusta basin, its outflowing shelfwaters are immediately intercepted by the surface Atlantic Ionian Stream (AIS) and mixed with the main gyres of the eastern Mediterranean Sea, thus representing a risk for the large-scale marine system.
Here we show the results of two morpho-bathymetric surveys carried out on the underwater archaeol... more Here we show the results of two morpho-bathymetric surveys carried out on the underwater archaeological area of the Pozzuoli Bay (Naples, Italy). Such area is enclosed in the Campi Flegrei active volcanic complex, where bradyseism and recent volcanic activity strongly influenced the coastline shape over the last 2 Ka. The Digital Elevation Model (DTM) of the seafloor allowed to draw the main archaeological features of the Bay, that also include the military complex of Portus Iulius and the ancient thermal and villa complex of Baianus Lacus. The extraction of archaeological features from DTM was achieved thanks to the use of a GIS-derived tool based on the profile curvature algorithm. Thus, the Villa dei Pisoni (1st Century B.C.) and the thermal complex of Secca delle Fumose were investigated by using ultra-high resolution DTMs, that show the presence of Roman pilae for the protection of coastal buildings and also the inner planimetry of the Villa dei Pisoni complex. The observation of coastal engineering structures give also the opportunity to formulate some hypothesis on the evolution of morphology and of the sedimentary pattern of the area, while depth of archaeological remains allowed a rough computation of the rate of subsidence, resulted to be 2.55 (AE0.5) mm/y for the Eastern sector (Pozzuoli) and 2.90 (AE0.5) mm/y for the western (Baia).
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Papers by Marco Barra