Laura Cutroneo

The Ligurian Sea: present status, problems and perspectives

The Ligurian Sea is a deep basin in the northernmost sector of the western Mediterranean which shows peculiar hydrodynamic and meteo-oceanographic features. The coasts of the Ligurian Sea are among the most urbanised and industrialised along the Italian coastline: the main causes of disturbance being littoral urban development and harbour activities, the building of littoral rail- and highways, and the presence of several polluted discharges. This review, by evaluating the huge scientific output published in the last three decades, describes and discusses the most important geological, hydrological and biological characteristics of the Ligurian Sea. We show that this regional sea has largely been investigated in terms of its geological and structural evolution, as well as in terms of the sedimentation dynamics of the littoral and deep bottoms, with particular attention to the sedimentation balance of the beaches and their erosive processes. We report that the prevalent hydrodynamic and meteo-oceanographic conditions favour a continuous exchange of coastal water masses, and that the seasonal and interannual dynamics of water masses can effects the local climate, with direct and indirect consequences on fish and benthic communities documented in the last decade. We stress that although recent studies offer good knowledge of the distribution of coastal benthic communities, only scant information is available for the whole continental shelf, the submarine canyons and the rocky bathyal bottoms. Our meta-analysis reveals that significant fishing activities are monitored, but also that certain sectors of the biological resource are suffering, and suggests the set up of appropriate management measures. The Ligurian Sea hosts a number of Marine Protected Areas (MPAs) of high relevance, while the institution of the Whale Sanctuary completes the protection policy of the Regione Liguria. Our meta-analysis points out the need for long-term studies, based primarily on the analysis of those areas of the Ligurian Sea that have been little investigated to date. Finally, only properly addressed studies, using experimental approaches and along appropriate spatial and temporal scales, might allow us to understand the functioning of the Ligurian marine ecosystems, evaluate their health conditions and the dynamics of the main variables that affect the distribution of the single species (including species of high economic value) and benthic communities.

Technical and public approaches to involve dredging stakeholders and citizens in the development of a port area

The stakeholders involved in a dredging operation are many and varied, some specifically involved in the technical aspects (client and dredging operators, organisations involved in legislative matters and/or environmental monitoring), and others less so (general public).These different kinds of stakeholders need different information and consequently different kind of data need to be produced (description of dredging objectives and scope, technical dredges characteristics, related legislation, environmental monitoring data, work progress, etc.) that need to be managed to share dredging information and knowledge. Here, we illustrate two examples of communication strategy adopted in the case of the dredging of the Port of Genoa (Italy) to ensure the correct data dissemination among the project partners and to the public. The first realized with a WebGIS (MArine Coastal Information SysTEm—Port Section, MACISTE-PS), a technology composed of data handling tools for storage, recovery, management and analysis of spatial data, and the second with a set of different communication products (posters, article publications, congress participations, website, etc.). The adoption of these two strategies assures us the dissemination of dredging information to a broad spectrum of people.

Physical and sedimentological characterisation of dredged sediments

Port dredging operations inevitably create a turbid plume around the dredge and it is necessary to follow the movement of this to impede its diffusion into the surrounding environment and reduce any negative impacts. To characterise the extension and concentration of the plume induced by dredging it is necessary to study the physical properties of the water, the residence time of the sediments in the water column and the diffusion velocity of the water and sediments. It is also essential to characterise the area and determine the specifics of the port environment under so-called normal maritime-traffic conditions. During the initial stage of such a study it is necessary to obtain measurements under diverse wind–wave conditions to characterise the physical features of the water column of the port area, the turbidity, the quantity and dimension of the suspended particulate matter and the current dynamics. In this article we present a series of physico-sedimentological operations to characterise a zone to be dredged based upon our experience during pre-dredging work in the Port of Genoa (Italy).

Marine sediment contamination and dynamics at the mouth of a contaminated torrent: The case of the Gromolo Torrent (Sestri Levante, north-western Italy)

In this study we have examined the currents and hydrological characteristics of the water column off the mouth of the Gromolo Torrent (north-western Italy) in relation to the grain-size, mineralogical characteristics and metal distribution in the marine sediment sampled. Our purpose was to quantify and map the contamination that was carried out to sea from the abandoned Libiola Fe-Cu sulphide mine that has heavily impacted the torrent. Our results show high concentrations of Cu and Zn, and relatively high concentrations of Cd and Ni inside the bay into which the Gromolo Torrent flows. However, high concentrations of As, Cr, Hg, Mn, Pb, and V found in the northern and/or eastern parts of the study area originated from other sources. The subdivision of study stations in terms of metal and mineral contents in the bottom sediments highlighted the clear influence of the currents on their dispersion and distribution in the area.

Simulations of dredged sediment spreading on a Posidonia oceanica meadow off the Ligurian coast, Northwestern Mediterranean

The sandy deposits from dredging can have negative effects on the environment such as increase in suspended solids in the water column and their consequent transport. An experimental study was conducted to characterize water masses, dynamics, and sedimentation rates on the Ligurian continental shelf (Italy), where both a sand deposit, that could be used for beach nourishment, and a nearby Posidonia oceanica meadow coexist. The environmental plan provides a mathematical simulation of the sediment-dispersion to evaluate the possible impact on the meadow. It has been calculated that the dredging could double the concentration of suspended particles, but its scheduling will preclude a sediment accumulation. All the information obtained from this work will be used to study the environmental feasibility of the sand deposit exploitation and as starting point for drawing up the monitoring plan in case of dredging.

Metal transport and remobilisation in a basin affected by acid mine drainage: the role of ochreous amorphous precipitates

Metal-polluted mine waters represent a major threat to the quality of waters and sediments in a downstream basin. At the confluence between acidic mine waters and the unpolluted waters of the Gromolo Torrent (Liguria, North-West Italy), the massive formation of an ochreous amorphous precipitate takes place. This precipitate forms a soft blanket that covers the torrent bed and can be observed down to its mouth in the sea. The aim of this work is to evaluate the dispersion of metals in the Gromolo Torrent basin from the abandoned Cu-Fe sulphide mine of Libiola to the Ligurian Sea and to assess the metal remobilisation from the amorphous precipitates. The mineralogy of the superficial sediments collected in the torrent bed and the concentrations of different elements of environmental concern (Cu, Zn, Cd, Co, Cr, Mn, Ni, Pb, As, and Sb) were therefore analysed. The results showed that the precipitates contain high concentration of Fe, Al, Cu, and Zn, significantly modifying the bulk chemistry of the Gromolo Torrent sediments. In order to evaluate the possible remobilisation of ecotoxic elements from the amorphous precipitates, bulk leaching tests were performed with both deionised and seawater. Bulk leaching tests with deionised water mobilised primarily high Pb amounts, but also relatively high concentrations of Fe, Al, Cu, and Zn are released in the leachate. In seawater tests, Fe, Al, Cu, and Zn were released in smaller amounts, while other elements like Mn, Cd, Co, and Ni increased in the released fraction. Pb was still strongly released as in deionised water experiments. The results show that the interaction of precipitates and seawater can remobilise high concentrations of metals, thus affecting the surrounding environment.

Environmental complexity of a port: Evidence from circulation of the water masses, and composition and contamination of bottom sediments

Ports are complex environments due to their complicated geometry (quays, channels, and piers), the presence of human activities (vessel traffic, shipyards, industries, and discharges), and natural factors (stream and torrent inputs, sea action, and currents). Taking these factors into consideration, we have examined the marine environment of a port from the point of view of the circulation of the water masses, hydrological characteristics, distribution of the sediment grain-size, mineralogical characteristics, and metal concentrations of the bottom sediments. Our results show that, in the case of the Port of Genoa (north-western Italy), the impact of human activities (such as a coal power-plant, oil depots, shipyards, dredging of the bottom sediments, etc.), natural processes (such as currents, fresh water and sediment inputs from the torrents), and the morphology of the basin, are important factors in the sediment, water, and metal distributions that have given rise to a complex environment.

Another possible risk for the Mediterranean Sea? Aspergillus sydowii discovered in the Port of Genoa (Ligurian Sea, Italy)

Aspergillus sydowii is a cosmopolitan fungus that has been responsible for the mass destruction of coral in the Caribbean Sea over the last 15years. To our knowledge, this study has found the first case of A. sydowii in the Mediterranean Sea, in marine-bottom sediments, water and calcareous shells of bivalve molluscs sampled during a campaign to characterise the mycobiota in the Port of Genoa (Italy). The area is characterised by adverse environmental conditions (high turbidity, organic pollution and high concentrations of phosphorus and nitrogen compounds). These parameters, in combination with a rising temperature, could contribute to A. sydowii bloom and dispersal. This fungal strain may have been imported into the Port of Genoa in the bilge water of vessels or by torrent input. This work represents the first step in the implementation of a monitoring programme to safeguard calcareous sponges and sea fan corals endemic in the Mediterranean Sea.

Evaluation of the boundary condition influence on PAH concentrations in the water column during the sediment dredging of a port

The mobilisation of sediments and related contaminants connected to dredging activities is one of the most critical issues to the environmental risk and exposure assessment of a dredging project. The aim of this paper was an investigation of the mobilisation of polycyclic aromatic hydrocarbons (PAHs) due to the dredging of the Port of Genoa (Italy) to identify the temporal and spatial extent of the contaminant transport, and the influence of the dredging and the boundary conditions on it. The results showed relatively low background PAH concentrations in the water column and confirmed the dredging as the primary rising factor of concentrations in the water column, but also showed a complex scenario in which the different environmental and dredging factors forced the concentrations at different levels and moments. The post dredging phase showed PAH values close to the background conditions and the concentrations remained relatively high only for a few PAHs.

Fungal characterisation of a contaminated marine environment: the case of the Port of Genoa (North-Western Italy)

ABSTRACT Nowadays, little information is available about how and if the contaminants may impact on the presence of marine fungi. Indeed, many environmental factors may facilitate the presence of specific fungal taxa. This paper deals with the mycodiversity of 22 stations characterised by contaminated seawaters of the Port of Genoa (North-Western Italy). Several substrates were taken into account and 319 vital strains were isolated belonging to 20 genera and 47 species. The most common genera were Aspergillus, Fusarium, Penicillium and Trichoderma. The fungal richness and mycodiversity were also evaluated and both appeared significantly high in most of these contaminated stations.