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The Gulf of Naples located in a high anthropized coastal area is subjected to an infrastructural intervention for the installation of a submarine power pipeline. In order to evaluate the distribution of contaminants in the seafloor sediments, a preliminary study has been conducted in the area using multivariate techniques. The statistic approach was performed to gain insights on the occurrence of organic and inorganic contaminants within the area, aiming to identify the relevant hot spots. Three geographical sub-areas influenced by different contaminant association were recognized: Torre Annunziata (TA), Capri (CA), and middle offshore (MO). TA and CA resulted marked by a severe contamination pattern due to anthropogenic pressures. In addition, the influence of the depositional basin in governing the contamination trend has been pointed out. The supervised technique PLS_DA resulted to be a powerful tool in addressing the complexity of the huge dataset acquired during the marine survey, highlighting the main trends in the variability of quality indicators, orienting thus the deeper investigations during follow-up monitoring activities., (© 2022. The Author(s).)

The effects of sediment resuspension on the fate of metals and polychlorinated biphenyls (PCBs) were studied by using a short-term small reactor. Sediments and water were collected nearby the most contaminated site of the Mar Piccolo of Taranto. Contaminant partitioning was calculated between the solid and water phases and, in the latter, between the dissolved and particulate phases and related to physical-chemical variables. Before and after resuspension, metal concentrations in sediments did not vary remarkably. Except for Cd, all the analyzed metals exceeded by many folds both threshold effect level (TEL) and probable effect level (PEL) SQGs. Igeo index values for Hg designated the sediment quality as extremely polluted for Pb, Cu and moderately polluted for Zn. In the dissolved phase, Mn increased of about 70 times, Fe of about 7 times and Hg and Zn of 4 and 3 times, respectively. PCBs in sediments before and after resuspension did not vary for more than 15 %. PCB concentrations exceeded for more than ten times PEL values. After resuspension, PCBs increased from 0.82 to 4.82 ng L(-1) in the dissolved phase and from 0.22 to 202.21 ng L(-1) in the particulate one. The dissolved phase was initially enriched in light- to mid-weight compounds. After resuspension, the particulate phase was enriched in heavier congeners. In particular, hexachlorobiphenyl-153, 149 and 138 together with heptachlorobiphenyl-180 and 187 accounted for 57 % of total PCBs. The dissolved organic carbon (DOC) that increased from 1.31 to 8.55 mg L(-1) likely influenced the fate of metals and PCBs in the dissolved and particulate phases. Despite that the residence time of the contaminated resuspended sediments in the water column is limited, they are still highly toxic for the pelagic trophic web.

In situ benthic flux experiments were conducted at two stations in the Mar Piccolo of Taranto (Italy), one of the most industrialised and contaminated coastal areas of the Mediterranean. Sediments of the two stations are notably different in their trace metal content, with a station closer to a Navy harbour showing higher mean concentrations of almost all investigated metals (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, V and Zn). Conversely, both stations are characterised by significant Hg contamination, compared to the local baseline. Results of a sequential extraction scheme on surface sediments suggest a relatively scarce mobility of the examined metals (Zn > Ni > Cr > As > Cu > Pb). A Hg-specific extraction procedure showed that most of the element (93.1 %) occurs in a fraction comprising Hg bound to Fe/Mn oxi-hydroxides. Reduction of these oxides may affect Hg remobilisation and redistribution. Porewater profiles of dissolved trace metals were quite similar in the two sites, although significant differences could be observed for Al, Cu, Fe and Hg. The highest diffusive fluxes were observed for As, Fe and Mn. Mobility rates of several trace elements (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, V and Zn) were directly measured at the sediment-water interface. Results from benthic in situ incubation experiments showed increasing dissolved metal concentrations with time, resulting in higher fluxes for Cu, Fe, Hg, V and Zn in the most contaminated site. Conversely, fluxes of Mn, Ni and Pb were comparable between the two stations. The estimated flux of Hg (97 μg m(-2) day(-1)) was the highest observed among similar experiments conducted in other highly contaminated Mediterranean coastal environments. Benthic fluxes could be partially explained by considering rates of organic matter remineralisation, dissolution of Fe/Mn oxy-hydroxides and metal speciation in sediments. Seasonal and spatial variation of biogeochemical parameters can influence metal remobilisation in the Mar Piccolo area. In particular, metals could be promptly remobilised as a consequence of oxygen depletion, posing a serious concern for the widespread fishing and mussel farming activities in the area.

The National Project RITMARE (la Ricerca ITaliana per il MARE-Italian Research for the sea) started from 1 January 2012. It is one of the national research programs funded by the Italian Ministry of University and Research. RITMARE is coordinated by the National Research Council (CNR) and involves an integrated effort of most of the scientific community working on marine and maritime issues. Within the project, different marine study areas of strategic importance for the Mediterranean have been identified: Among these, the coastal area of Taranto (Ionian Sea, Southern Italy) was chosen for its different industry settlements and the relative impact on the marine environment. In particular, the research has been concentrated on the Mar Piccolo of Taranto, a complex marine ecosystem model important in terms of ecological, social, and economic activities for the presence also of extensive mussel farms. The site has been selected also because the Mar Piccolo area is a characteristic "on field" laboratory suitable to investigate release and diffusion mechanisms of contaminants, evaluate chemical-ecological risks towards the marine ecosystem and human health, and suggest and test potential remediation strategies for contaminated sediments. In this context, within the project RITMARE, a task force of researchers has contributed to elaboration a functioning conceptual model with a multidisciplinary approach useful to identify anthropogenic forcings, its impacts, and solutions of environmental remediation. This paper describes in brief some of the environmental issues related to the Mar Piccolo basin.

Total mercury and methylmercury concentrations were measured in sediments and marine organisms from the Taranto Gulf to understand their distribution and partitioning. Sediment concentrations ranged from 0.036 to 7.730 mg/kg (mean: 2.777 mg/kg d.w.) and from 1 to 40 μg/kg (mean: 11 μg/kg d.w.) for total mercury (THg) and methylmercury (Me-Hg), respectively. In mollusks THg ranged from n.d. to 1870 μg/kg d.w. while in fish from 324 to 1740 μg/kg d.w. Me-Hg concentrations in fish ranged from 190 to 1040 μg/kg d.w. and from n.d. to 1321 μg/kg d.w. in mollusks. THg exceeded the maximum level fixed by the European Commission (0.5 mg/kg w.w.) only in gastropod Hexaplex t. The calculated weekly intake was in many cases over the Provisional Tolerable Weekly Intake established by EFSA for all edible species. These results seem to indicate that dietary consumption of this seafood implicates an appreciable risk for human health., (Copyright © 2011 Elsevier GmbH. All rights reserved.)

The goal of this study was to assess coastal marine pollution in the Mar Piccolo and Taranto Gulf (Ionian Sea, Southern Italy) by combining chemical and toxicological data in order to compare and integrate both approaches. Pollutants levels, traditionally, have limited ability to predict adverse effects on living resources. Moreover, in order to provide information on the ecological impact of sediment contamination on aquatic biota Numerical Sediment Quality Guidelines (SQGs) and sediment toxicity bioassays were carefully recommended. In this study ERL (effect range low)/ERM (effect range medium value) and TEL (threshold effect level)/PEL (probable effect level) guidelines have been used. Bioassays were performed with two species of amphipods Gammarus aequicauda and Corophium insidiosum, one species of isopod Idotea baltica and bivalve Mytilus galloprovincialis larvae. The TEL/PEL analysis suggested that, especially for stations 1 and 2, sediments in Mar Piccolo should contain acutely toxic concentrations of metals. In particular Hg content, in station 1, was about 17 times PEL value. 96 h LC(50) and 48 h EC(50) values were estimated for cadmium, copper and mercury in these species using the static acute toxicity test. M. galloprovincialis larvae was more sensitive than other species to all the reference toxicants tested (EC(50) determined for cadmium copper and mercury were of 0.59, 0.11 and 0.01 mg/l respectively). Significant differences in sensitivity of species tested to all reference toxicants (ANOVA p < 0.001) were recorded. Bioassays with these species allowed to estimated sediment toxicity from the different studied sites. On the basis of results obtained a good agreement was reported between chemical data and response of the biological endpoints tested.

Polychlorinated biphenyls (PCBs) and 17 parent polycyclic aromatic hydrocarbons (PAHs) were determined in surface sediments from nine stations in the Mar Piccolo of Taranto (Ionian Sea, Southern Italy). Total PAH concentrations ranged from 380 to 12,750 microg/kg d.w., while total PCB levels ranged from 2 to 1684 microg/kg d.w.; this values were higher than those found in others marine coastal areas of the Mediterranean Sea. For PAHs, low molecular weight/high molecular weight, phenanthrene/anthracene and fluoranthene/pyrene ratio were used for discriminating between pyrolitic and petroleum origin. Results showed that PAHs were mainly of pyrolitic origin. PCB and PAH levels in sediments were compared with Sediments Quality Guidelines (ERM-ERL, TEL-PEL indexes) for evaluation probable toxic effects on marine organism. Finally, ERM and PEL quotients were used to evaluate the degree to which chemicals exceed guidelines. Results suggest an ecotoxicological risk for benthic organisms mainly in the first inlet, where high concentrations of PCBs were found in sediments influenced by harbour activities.

Heavy metals concentrations (Cd, Cu, Hg, Pb, Sn and Zn) have been determined monthly in surface sediments from the Mar Piccolo in Taranto (Ionian Sea, Southern Italy. a semi-enclosed marine basin very important from a mussel-culture point of view. In sediments, sulphides, percentage of organic carbon and redox potential were also determined to show possible correlations between metals levels and redox characteristics of marine sediments. Analytical results, elaborated by multivariate statistical techniques, confirm that sediments collected in the first inlet of Mar Piccolo, where shipbuilding activities are present, have a contamination level greater than those collected in the second inlet. For each metal, the geoaccumulation index (Igeo) has been calculated as criterion to evaluate both pollution levels and metals enrichment in examined sediments: Igeo values confirm that the first inlet is an moderately polluted area from Hg and Pb. In any case, high sulphide concentrations and negative values of redox potentials bring to a conclusion that metals are present in sediments, mainly as insoluble sulphides and then as not bioavailable compounds for filter feeders organisms such as mussels.

Humic compounds were determined in sediments collected in an area of the Adriatic sea receiving fresh waters from the river Po. Sediment cores (10 cm) were sectioned into four layers which were analysed separately for redox potential (Eh), total phosphorus (TP), total organic carbon (TOC), humic (HA) and fulvic acid (FA) content. The structure of HA and FA was also investigated. The results showed that the TOC and TP content decreased from the coast to the open-sea stations. Humic and fulvic acid concentrations were also inversely correlated to the distance from the coast. Moreover, the humic and fulvic acids were closely correlated to the total organic content and to the total phosphorus content. The correlations found between humic substances (HS) and TOC and TP, respectively, could be explained both by an in situ formation due to the high content of nutrients and organic matter, and by a common source of HS, TOC and TP, namely the River Po discharge. The predominant presence of aliphatic carbon in the humic structures, the low degree of substitution and the high nitrogen content suggest that primarily humified compounds were formed in situ. Nevertheless, the River Po can act both as supplier of organic matter of which decomposition products lead to the formation of humic compound and as carrier of humified compounds.

Marine sediments from the Mar Grande and Gulf of Taranto were analysed for 17 parent PAHs, with molecular weight from 128 to 278 Daltons. The analyses were performed by gas chromatography coupled to mass spectrometry (GC-MS). Total PAHs content in sediments ranged from 464 to 12522 microg kg(-1) dry wt for Mar Grande and from 593 to 72275 microg kg(-1) dry wt for Gulf of Taranto. The analytical results were compared with the published results for other coastal areas in the Mediterranean Sea. PAHs levels in the Gulf of Taranto sediments were the highest in the Mediterranean sea, while PAHs concentrations in Mar Grande were higher than the ones reported in the Adriatic and Cretan Sea and with the same order of magnitude of the ones known for coastal areas of the Western and the Eastern Mediterranean Sea. PAHs concentration ratios were consistent with the main source of these compounds, in most areas, being pyrolysis. Based on the comparison of both the individual and the total PAHs concentrations with proposed sediment quality guidelines, the acute biological effects on the marine organisms were probable, especially for the Gulf of Taranto, in which almost all PAHs concentrations in sediments were higher than the guidelines limit values. The statistical analysis effected by HCA and PCA methods was used in order to classify sediment samples and to identify accumulation areas.

Concentrations of metals (Al, Fe, Ti, Ni, Mn, Cr, Zn, Cu, Pb) were determined in surface sediments from Taranto gulf (Ionian Sea, Southern Italy) in order to assess the distribution and the bioavailability of metals. Total metal content and speciation of Fe, Ni, Mn, Zn, Cu and Pb were determined. Sediment cores were also sampled in some stations of particular interest. The analytical results show that metals distribution does not show significant variations in relation to depth. Metal distribution in the Taranto gulf is mainly influenced by industrial wastes from Taranto town, by rivers of the Basilicata region and by prevailing anticlockwise marine currents. These factors cause an accumulation of metals in the sediments near to the coasts of Calabria. The statistical analysis, effected by HCA and PCA methods, can be considered a good starting point in order to classify sediment samples and to locate accumulation areas. Metal speciation shows that Fe, Ni and Zn are present in sediments mainly as sulphides, Mn is present principally in an ion-exchange form or bound to carbonate, while Cu and Pb are mainly present in the fraction bounds to humic acids.

The concentrations of 17 parent PAHs, with molecular weight from 128 to 278 Daltons, were determined in surface sediments from the Mar Piccolo of Taranto. The analytical results were compared with the published results for other coastal areas of the Mediterranean Sea. The analyses were performed by gas chromatography coupled to mass spectrometry (GC-MS). Total PAH content in sediments ranged from 380 to 12750 ng g(-1) dry weight. The levels of the PAHs was higher than the one reported for sediments of the Adriatic Sea and Cretan Sea and of the same order of magnitude of the one known for coastal areas of the western and the eastern Mediterranean Sea. The PAHs distribution showed similar patterns in all sediments analyzed, with compounds with three or more rings. These patterns of distribution and the ratios among low molecular weight PAHs/high molecular weight PAHs, phenanthrene/anthracene and fluoranthene/pyrene indicated that pyrogenic inputs are the main source of these compounds in the Mar Piccolo basin. Based on the comparison of both the individual and the total PAH concentrations with proposed sediment quality guidelines, the acute biological effects on the marine organisms should be negligible.