Sediment

The assessment and characterization of pollutants load in the sediments represent a critical step for the evaluation of the environmental status of marine coastal areas.
The principal organohalogen compounds present in the Mediterranean coastal waters and sediments are polychlorinated biphenyls (PCBs);
dichlorodiphenyltrichloroethane (DDT) and its metabolites dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD); hexachlorocyclohexane (HCHs) and hexachlorobenzene (HCB).
The principal transport routes of these compounds into the marine and coastal environment include atmospheric deposition and surface run-off (UNEP, 1996). Human activities had led to the background concentration of these anthropogenic compounds.
We investigated concentration and distribution of POPs in a pilot study of a coastal area along the Tuscany coast, near the mouth of the
Ombrone River. The area is located between the Argentario Promontory and the Gulf of Follonica (Central Italy), south of the Ombrone delta.
The basin is characterised by natural processes of transport and the morphology of the coast is dominated by the Ombrone River delta.
The analytical results were treated with Principal Component Analysis (PCA)
in order to investigate the relationship among selected variables as well as to assess the spatial distribution of POPs in the studied area. The PCA results were confirmed by applying the Pearson’s correlation coefficient.

The coast of the Gulf of Orosei (Sardinia, Italy) consists of impressive cliffs set up on dolostones and limestones characterized by wide karst systems connected to the sea. Marine caves, which are part of these system flooded by seawater through marine entrances, may be considered as extreme environments because of wide spatial and temporal environmental variability due to changing marine and terrestrial contributions. This study presents the results of the third survey carried out in summer 2016 in the Bue Marino cave, as part of a research project started in 2014 aimed at the application of Benthic Foraminifera (BF) as ecological indicators in Mediterranean marine caves for the identification of different habitats and their environmental interpretation. Sediment and water samples were collected from a total of 25 stations from two distinct sectors of the cave (North Branch and Middle Branch); sediments were analysed for living and dead BF and grain size, while Temperature, Salinity, pH and Dissolved Oxygen were measured in water samples collected close to sediment water interface. Two main foraminiferal assemblages, with distinct characteristics with respect to the typical Mediterranean shallow-water ones, were recognized by means of Hierarchical Cluster Analysis and Non-metric Multidimensional Scaling, and a Canonical Correspondence Analysis deduced their environmental significance. A well oxygenated, less saline environment with coarse bottom sediment, correlated with a mixed calcareous-agglutinated assemblage (Gavelinopsis praegeri, Rosalina spp., Eggerelloides advenus and Reophax dentaliniformis) with high species diversity (H-index 2.32-3.57) and low foraminiferal density, was exclusive of the North Branch. A scarcely oxygenated, more saline environment with fine bottom sediment enriched in vegetal debris was related to a prevalently agglutinated assemblage characterized by low species diversity (H-index 1.60-2.68), with high dominance of E. advenus (up to 83.6%) associated to Ammonia tepida, and high foraminiferal density, recognized in the Middle Branch. These different environments were interpreted considering the different modes of feeding the karst systems of the two branches. They also corresponded to two distinct ecozones, Entrance and Confluence, already recognized in earlier studies. The environmental significance of the foraminiferal ecozones recognized in this study and their comparison with the ones identified in the previous years, helped to consider the ecological zonation as a tool for detecting seasonal and, possibly, long term annual environmental variability in the marine system. considered as natural laboratories where studying the response of such organisms to environmental variability, improving scientific knowledge on the effects of global changes. Several habitats may be recognized as extreme environments in the marine realm; they range from transitional zone to deep sea and include the intertidal belt, marshes and lagoons, hydrothermal vents, marine blue holes, but also extremely oligotrophic,

Book of the 18 International Conference on Heavy Metals in the Environment, 12 to 15 September 2016, Ghent, Belgium This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. – 159 – 18th International Conference on avy Metals in the Environment 12 to 15 September 2016, Ghent, Belgium ICHMET 2016 Proceedings of the 18 International Confer nce on Heavy Metals in the Environment, 12 to 15 September 2016, Ghent, Belgium

Marine caves are characterized by wide environmental variability for the interaction between marine and continental processes. Their conditions may be defined as extreme for inhabiting organisms due to the enclosed morphology, lack of light, and scarcity of nutrients. Therefore, it is necessary to identify reliable ecological indicators for describing and assessing environmental conditions in these habitats even more than elsewhere. This review aims to provide the state of art related to the application of benthic foraminifera as proxies in the (paleo)ecological characterization of different habitats of marine caves. Special attention was addressed to a research project focused on Mediterranean marine caves with different characteristics, such as extent, morphology, freshwater influence, salinity, sediment type, oxygenation, and organic matter supply. This review aims to illustrate the reliability of foraminifera as an ecological and paleoecological indicator in these habitats. They...

Intensive exploitation of base metal deposits in the Sulcis-Iglesiente district (Sardinia, Italy), lasted from the 1850s to the 1990s, determined a high environmental impact on the coastal area, but the effects on marine environment have never been investigated. A marine sediment core, dated with (14)C, was characterized for grain size, chemical and mineralogical composition, in order to reconstruct the sedimentary history of the area and to assess the environmental impact of mining. The comparison of chemical and mineralogical characteristics of recent sediments with those of pre-industrial age allowed discriminating the real anthropogenic impact from the natural metal enrichment. The correspondence, in the upper core, of anthropogenic trace metal enrichment with the presence of mine waste minerals is attributed to the exploiting over industrial scale; the still high metal enrichment in sediment surface levels suggests a still existing impact due to mine dumps and tailings weathering.

Many studies finalised to a reclamation project of the industrial area were carried out on the industrial site of Bagnoli (Naples). Among these studies, the sedimentological, chemical, and ecological characteristics of marine sediments were analysed. Seven short cores, located in the proximity of a steel plant, were analysed for grain-size, polychlorobiphenyls, polycyclic aromatic hydrocarbons and heavy metals. As well, benthic foraminiferal assemblages were investigated. Sediment pollution was mainly due to heavy metals; in particular, copper, mercury and cadmium showed a ‘spot’ (site-specific) distribution, while iron, lead, zinc and manganese showed a diffuse distribution, with a gradual decrease of concentration from coast to open sea. Heavy metals pollution seems to explain some of the variation in the foraminiferal abundance. The combined copper and iron contamination might be the cause for the complete absence of foraminifera in the four shallower cores. Moreover, the ratio b...

The present article explain how potentially contaminated sediment thickness in Augusta harbour was estimated by using a multisource dataset characterized by a variable accuracy. Inequalities constrains on the sediment thickness are extracted from the sediment sampling stations and seismic profiles in which the hard irregular sub-bottom was out of detection range (soft data). It utilized the kriging-withinequalities method that belongs to the data transformation group. The method considers the inequalities constraints as data themselves and, after a transformation, their use together with the exact hard data to estimate the thickness of the sediment layer. The results show the usefulness of an approach that permitted to extract the maximum information from multisource data, collected for different purposes, in order to assess the 3D spatial domain of recent contaminated sediment and reduce the cost of management.

From the early 1950s until the late 1970s, Augusta Bay (Sicily, Italy) served as a major European (petro) chemical hub. It thereafter began a progressive decline as several crude oil refining and industrial plants closed due to the transfer of production cycles to other sites around the globe. As a result of the rapid and relatively uncontrolled post-WWII development of the site, several environmental studies identified significant contamination in sediments around the southernmost sector of the bay. The pollution was mainly due to barium (Ba) and mercury (Hg), attributable to the former chlor-alkali plant (1958-2003), and polychlorobiphenyls (PCBs) and hexachlorobenzene (HCB). The present study focuses on understanding the broad legacy of pollution across the whole harbour by systematically analysing 10 sediment cores collected in 2008 for contaminant concentration profiles of Hg, Ba, PCBs, HCB and grain-size variations. Pre-industrial environmental geochemical background conditions were identified using data from the deeper parts of cores. The results show that contamination has affected the entire harbour area to varying degrees, and this has allowed identifying contamination transfer, based on decreasing concentrations and related depths in the sediment cores from the southernmost sector to the central and northern area. A recent finding by the current researchers is that the construction of the dam/breakwater in the early 1960s, that largely coincided with the start of industrial inputs, led to the trapping of fine terrestrial sediment inside the harbour, particularly in the central and northern area. This trapped sediment provides a granulometric time marker in those cores. The presence of highly contaminated sediments inside the harbour represents a significant future liability unless remedial action is applied to remove the worst of the polluted sediment.