Current observations from a looking down vertical V-ADCP: interaction with winds and tide? The case of Giglio Island (Tyrrhenian Sea, Italy)

Summary In the context of the environmental monitoring of the Concordia wreck removal project, measurements of currents, winds and sea level height were made along the eastern coast of the Giglio Island, Tyrrhenian Sea (Italy), during 2012–2013. The aim of the study was to investigate the effect of atmospheric forcing and periodic sea-level changes on the coastal currents. Normalised Cross-Correlation Function analysis allowed us to correlate these observations. A marked inter-seasonal variability was found in both current and local wind velocity observations but a significant level of correlation between the data was only found during strong wind events. Current and wind directions appeared to be uncorrelated and current measurements showed a predominant NW–SE direction, presumably linked to the shape and orientation of Giglio Island itself. During strong winds from the SSE, current flow was towards the NNW but it suddenly switched from the NNW to the SE at the end of wind events. The results show that, at Giglio Island, currents are principally dominated by the general cyclonic Tyrrhenian circulation, and, secondly, by strong wind events. The sea level had no effects on the current regime

Correction to: Microplastics in seawater: sampling strategies, laboratory methodologies, and identification techniques applied to port environment

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The nepheloid bottom layer and water masses at the shelf break of the Western Ross Sea.

In the austral summers of 2000/01 and 2002/03 the Italian CLIMA Project carried out two oceanographic cruises along the north-western margin of the Ross Sea, where the Antarctic Bottom Water forms. Here there is an interaction between the water masses on the sea floor of the outer shelf and slope with a consequent evolution of benthic nepheloid layers and an increase in Total Particulate Matter. We observed three different situations: (a) the presence of triads (bottom structures characterized by a concomitant jump in turbidity, temperature and salinity data) and high re-suspension phenomena related to the presence of the Circumpolar Deep Water and its mixing with cold, salty shelf waters associated with gravity currents; (b) the absence of triads with high re-suspension, implying that when the gravity currents are no longer active the benthic nepheloid layer may persist until the suspended participles settle to the sea floor, suggesting that the turbidity data can be used to study recent gravity current events; and (c) the absence of turbidity and sediment re-suspension phenomena supports the theory that a steady situation had been re-established and the current interaction no longer occurred or had finished some time before

Settling Velocity of Microplastics Exposed to Wave Action

International audienceMicroplastic (MP) debris is recognized to be one of the most serious threats to marine environments. They are found in all seas and oceanic basins worldwide, even in the most remote areas. This is further proof that the transport of MPs is very efficient. In the present study, we focus our attention on MPs’ transport owing to the Stokes drift generated by sea waves. Recent studies have shown that the interaction between heavy particles and Stokes drift leads to unexpected phenomena mostly related to inertial effects. We perform a series of laboratory experiments with the aim to directly measure MPs’ trajectories under different wave conditions. The main objective is to quantify the inertial effect and, ultimately, suggest a new analytical formulation for the net settling velocity. The latter formula might be implemented in a larger scale transport model in order to account for inertial effects in a simplified approach

Applicability of an empirical law to predict significant sea-wave heights from microseisms along the Western Ligurian Coast (Italy)

The use of microseisms with appropriate predictive laws is a reliable method for estimating such seawave parameters as period and significant height. Through the use of opportune predictive laws calibrated with measurements obtained from wave buoys, it is possible to determine the significant height of the wave as a function of the spectral energy-content of the microseism. In this paper we will present a procedure that utilises microseisms recorded by a micro network of five seismic stations to predict the significant height of waves, and its uncertainty, along the western Ligurian coast (Italy). The calibration and validation of the procedure was performed using wave measurements obtained from a wave buoy off Capo Mele (Imperia, Italy) over a two and a half year period. The differences between the significant heights measured by the wave buoy and the empirical predictions were less than 10 cm (corresponding to 10% of the mean measured value) for 47% of the data and less than 20 cm (corresponding to 20% of the mean measured value) for 72%

Multi-mycotoxin determination in plant-based meat alternatives and exposure assessment

The aim of this study was to fill in the gap regarding the occurrence of mycotoxins in plant-based meat alter-natives. Hence, a multi-mycotoxin method (aflatoxins, ochratoxin A, fumonisins, zearalenone, and mycotoxins from the Alternaria alternata genera) was developed followed by an exposure assessment for the Italian con-sumers' exposure to mycotoxins. A total of 13 meat alternatives samples based on soy, pea, chickpea, lupin, and seitan were analysed. With the exception of seitan, all of the remaining samples were contaminated with one mycotoxin or mixtures of up to seven mycotoxins. The level of contamination was as low as 0.2 mu g/kg alternariol methyl ether and as high as 66.9 mu g/kg fumonisin B1. To analyse the exposure to mycotoxins due to plant-based meat alternatives consumption we used the consumption meat data from the Food and Agriculture Organization for Italian adult consumers and simulated a full replacement of meat with plant-based meat alternatives. Based on our model, consumption of plant-based meat alternatives led to a non-tolerable exposure to alternariol (hazard index (HI) > 1) in pea-based burger and soy + wheat-based steak, while samples contaminated with aflatoxins, respectively ochratoxin A, indicated a health concern related to liver and renal cancer (margin of exposure (MOE) < 10,000). This is the first study that presents the co-occurrence of mycotoxins in multiple plant -based meat alternatives. Moreover, these results indicate that there is a need for policymakers to consider the regulation of mycotoxins in plant-based meat alternatives in order to ensure consumers' safety

Changes in the physical characteristics of the water column at the mouth of a torrent during an extreme rainfall event

The city of Genoa (Italy) was hit by a severe flash flood on the 4th November, 2011. The effects of this event on the water column at the mouth of the Polcevera Torrent, the main water course flowing into the Port of Genoa, are presented in this paper. The hydrological characteristics were measured with two conductivity\u2013temperature\u2013depth probes equipped with a turbidimeter, one fixed on the port breakwater and one used at mobile stations around the mouth of the torrent. The dynamics were measured with a horizontal acoustic Doppler current profiler (H-ADCP) fixed on the breakwater. Data collected before, during and after the flash flood were analysed to quantify the changes due to the event. The weather conditions during the event showed extremely heavy rain associated with strong weather instability, the convergence of a low-level southerly flow and the persistence of a squall line over a restricted area. The temperature, salinity, turbidity and dissolved oxygen measurements taken during the event showed the strong influence of the weather conditions and the fresh water input of the torrent itself on the water column at its mouth, an influence that dissipated during the following days. Instead, the dynamics measured at the mouth of the torrent were affected more by the strong south-easterly wind and the sea than the flow of fresh water

Benthic diatom community response to metal contamination from an abandoned Cu mine: Case study of the Gromolo Torrent (Italy)

Environmental contamination has become a global problem of increasing intensity due to the exponential growth of industrialization. One main debated issue is the metal contamination of rivers receiving Acid Mine Drainage (AMD) from active/abandoned mines. In order to assess the quality of lotic systems, diatoms are commonly used, as their assemblage modifies on the basis of changes in environmental parameters. Benthic diatom changes were analyzed along the metal-impacted Gromolo Torrent (Liguria, NW Italy) with the aim of understanding the effects of input from the abandoned Libiola Cu mine. The results support the hypothesis that metals from AMD lead to massive changes in diatoms, resulting in low biological diversity and in a shift of dominance, passing from the genera Cymbella and Cocconeis to more tolerant and opportunistic species, such as Achnanthidium minutissimum and Fragilaria rumpens. The high concentrations of labile metals, measured through Diffusion Gradients in Thin-films (DGT) immediately downstream of the two AMD inputs in the torrent, corresponded to a sudden decrease in the presence of diatoms, indicating the possible reaching of acute toxic levels. In particular, A. minutissimum dominated the mining area and was positively correlated with Cu and Zn; whereas F. rumpens bloomed downstream of this area, where the metal content was diluted, and was positively correlated with As and Pb. Finally, an important abundance of Nitzschia palea and teratological forms of A. minutissimum and F. rumpens were observed downstream from the mine, indicating that metals may have an important impact on diatoms up to the torrent mouth

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