Descrizione del GIS/database implementato: sito di Portoscuso

Una delle attività previste nella Fase II del progetto riguardava la costruzione di un database e di un GIS per i dati dei due siti selezionati nella Fase I: Oristano e Portoscuso [Muscas e Cau, 2000, Muscas et al., 2000]. Per il sito di Oristano tale attività è stata realizzata nella Fase II, mentre il ritardo con cui sono stati reperiti i dati relativi al sito di Portoscuso ha comportato lo slittamento di questo lavoro alla Fase III. Nel presente rapporto viene descritta l’implementazione del GIS/database del sito di Portoscuso. Anche per il sito di Portoscuso, come per Oristano, gli applicativi GIS utilizzati sono stati: ArcInfo e ArcView, entrambi della ESRI [Muscas e Cau, 2000]. In particolare ArcInfo è stato utilizzato per la correzione degli errori, costruzione della topologia e creazione ex novo di nuovi livelli informativi. Il GIS realizzato è stato invece organizzato in un progetto Arcview

Descrizione del GIS/database implementato: sito di Oristano

Sono ormai note le potenzialità dei sistemi informativi geografici GIS. La capacità di eseguire analisi spaziale rappresenta la parte fondamentale del GIS, ne motiva l’utilizzo e ne giustifica la sua grande diffusione. La seconda fase del progetto “Ambiente e territorio. Tecnologie avanzate per la gestione delle acque. Software per la modellistica ambientale" è stata dedicata alla formalizzazione degli algoritmi risolutivi e delle modifiche da introdurre ai modelli numerici e alla raccolta ed elaborazione dei dati necessari alla realizzazione del sistema informativo geografico. I siti individuati per la costruzione del GIS sono: l'area di Oristano (Sardegna centro occidentale) caratterizzata da un alto grado di vulnerabilità dell'acquifero dovuto presumibilmente a fenomeni di intrusione salina, e l'area di Portoscuso (Sardegna sud occidentale), sede di agglomerati industriali caratterizzata da inquinamento dovuto a metalli pesanti e fenomeni di intrusione salina nell'acquifero

Identificazione dei siti di studio e organizzazione del sistema GIS/database. Stato di avanzamento attività 3.2

Nel presente rapporto viene presentato lo stato di avanzamento dell'attività 3.2 ad un anno dall'inizio del progetto. Detta attività consiste nella realizzazione di un sistema informativo per ciascuno dei siti selezionati comprensivo di mappe, archivi, dati, etc. da utilizzare successivamente per le simulazioni. In questo contesto il lavoro è consistito nell'acquisizione, gestione e analisi di dati eterogenei provenienti da diverse fonti informative. Tali dati sono costituiti da rilievi in campo e/o in laboratorio, cartografia esistente e simulazioni eseguite con i modelli numerici di calcolo che in alcuni casi sono di tipo dinamico, cioè variabili nel tempo. Mediante l'uso di software GIS commerciali, i dati sono stati organizzati e convertiti in formati consistenti fra loro, e in seguito inseriti e elaborati all'interno del GIS stesso, in modo da arrivare ad un sistema dinamico per la gestione, l'analisi e la rappresentazione dei vari tipi di dati (alfanumerici, tabelle, raster, vettoriali; dati statici e dinamici; etc.). Operazioni di georeferenziazione e correzione in molti casi sono state particolarmente impegnative a causa della scarsa qualità dei dati stessi. Entrando in maggiore dettaglio sull`attività svolta durante il primo anno, si è fatto un primo “screening” su una serie di siti in Sardegna e non. Questi siti presentano problemi di inquinamento di una certa rilevanza e ad una prima analisi si sono dimostrati dei validi candidati per uno studio maggiormente approfondito. I siti considerati per lo studio preliminare vengono elencati qui di seguito: Ringe, Capoterra, Portoscuso, Muravera, Oristano. Viene data una descrizione di massima dei siti in studio e dei problemi di inquinamento a cui sono soggetti. Infine, sulla base di una serie di considerazioni viene descritta la scelta dei due siti su cui si focalizzerà il progetto

Marine macro-litter mass outweighs biomass in trawl catches along abyssal seafloors of Sardinia channel (Italy)

: This study provides new insights onto spatial and temporal trends of seafloor macro-litter in the abyssal seafloor of Sardinian channel, in central western Mediterranean (Italy). Trawl surveys were conducted at depths between 884 and 1528 m, thus focusing on one of the least investigated marine environments. None of the considered sites was litter free, with plastics being numerically dominant (57% of items), followed by metal (11%) and glass (16%). Recorded densities and weight ranged between 49.9 and 499 items km-2 and 1.4 and 1052 kg km-2. In the most contaminated sites, the weight of the litter collected in nets represented up to nine times the biomass of benthic megafauna, and, overall, in 60% of hauls macro-litter mass outweighed the biomass collected. Moreover, we report that megafauna was observed to be more abundant in sites where macro-litter presence was more severe. More studies are needed to elucidate the nature of this correlation, with biota being more abundant in hotspots of accumulation of seafloor macro-litter

Onboard Scientific Observers Provide a Realistic Picture of Harvesting and Management Priorities for the Precious Red Coral (Corallium rubrum L.)

Mediterranean red coral Corallium rubrum is considered the most precious coral worldwide. Harvesting activities are performed by licensed scuba divers and managed through the recent pan-Mediterranean management plan issued by General Fisheries Commission for the Mediterranean (GFCM) along with measures locally enacted, imposing limits on licenses, harvesting season, minimum depth of dive, and size. The use of Remotely Operated Vehicles (ROVs) is prohibited, with the only exception being for scientific purposes. Despite measures already in force, the implementation of additional management tools has been recently recommended. This article reports results from the first monitoring campaign on C. rubrum harvesting based on ROVs for seabed exploration and Onboard Scientific Observers (OSOs), carried out from 2012 to 2015 along the coast of Sardinia (Mediterranean Sea—Western basin). More than 450 dives were monitored, confirming how ROV's support eases the scouting of exploitable banks, leading to increases in catches. OSOs reported the collection of colonies below the minimum reference size and catches/dive above limits. Onboard observers collected data also on colony diameter, which is crucial for the estimation of population size structure and exploitation status. OSOs proved to be valid tools in providing additional and reliable information on red coral harvesting, thus deserving to be included among mandatory measures for the sustainable exploitation of red coral in the Mediterranean Sea

Microplastics impair extracellular enzymatic activities and organic matter cycling in oligotrophic sandy marine sediments

Microplastics (MPs) are ubiquitous and constantly accumulating in the marine environment, especially sediments. Yet, it is not well clarified if and how their carbon backbone could interact with surrounding sediments, eventually impairing key benthic processes. We assessed the effects of a ‘pulse’ contamination event of MPs on sedimentary organic matter (OM) quantity, quality and extracellular enzymatic activities (EEAs), which are well established descriptors of benthic ecosystem functioning. Marine sediments were exposed for 30 days to environmentally relevant concentrations (∼0.2 % in weight) of naturally weathered particles (size range 70–210 μm) of polyurethane, polyethylene, and a mixture of the most common polymers that are documented to accumulate in marine sediments. Despite the low concentration, contaminated sediments showed significantly different composition of OM, showing a decrease in lipid content and increase in protein. Moreover, we document a significant decrease (over 25 %) in quantity of biopolymeric C already after 15 days of exposure, compared to controls. Contaminated sediments showed lower C degradation rates (up to −40 %) and altered EEAs, with alkaline phosphatase being ∼50 % enhanced and aminopeptidase being reduced over 35 % compared to control treatments. Overall, the effects generated by the mixture of polymers were smaller than those exerted by the same amount of a single polymer. Our results provide insights on how that MPs can significantly alter marine sedimentary biogeochemistry through altered benthic processes, that could cumulatively impair whole benthic trophic webs by enhancing the accumulation and possible longer-term storage of recalcitrant organic C in the seabed

Interplay of Staphylococcal and Host Proteases Promotes Skin Barrier Disruption in Netherton Syndrome.

Netherton syndrome (NS) is a monogenic skin disease resulting from loss of function of lymphoepithelial Kazal-type-related protease inhibitor (LEKTI-1). In this study we examine if bacteria residing on the skin are influenced by the loss of LEKTI-1 and if interaction between this human gene and resident bacteria contributes to skin disease. Shotgun sequencing of the skin microbiome demonstrates that lesional skin of NS subjects is dominated by Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). Isolates of either species from NS subjects are able to induce skin inflammation and barrier damage on mice. These microbes promote skin inflammation in the setting of LEKTI-1 deficiency due to excess proteolytic activity promoted by S. aureus phenol-soluble modulin α as well as increased bacterial proteases staphopain A and B from S. aureus or EcpA from S. epidermidis. These findings demonstrate the critical need for maintaining homeostasis of host and microbial proteases to prevent a human skin disease

Design, Test and Analysis of a Gyrotron Cavity Mock-Up Cooled Using Mini Channels

In 2016, we have designed, built and finally tested at the FE200 facility in Le Creusot (France) a planar mock-up mimicking the water-cooled cylindrical resonance cavity of the European 170 GHz, 1 MW gyrotron to be used for electron cyclotron plasma heating in ITER. The aim of the mock-up is the characterization of the cooling capability of the cavity. A Glidcop® target is heated with an electron beam gun with resulting peak heat fluxes relevant for the full-size cavity. Underneath the target surface, whose temperature is monitored by means of a pyrometer, a set of parallel semi-circular mini-channels, with diameter of 1.5 mm, allows the flow of pressurized water, entering the mockup at ~ 9 bar and 40 °C. Several thermocouples measure the target temperature, at different distances from the heated target surface. The experimental results show that the mock-up is capable to withstand a heat fluxes of 21 MW/m2, while the cooling system keeps the heated surface below ~ 400 °C, for flow conditions comparable to those of the full-size cavity. The test results are used to first calibrate the uncertain model parameters and then, with frozen parameters, to validate a previously developed CFD model, showing good agreement with the experiment. In view of its reliability, this model might eventually be a useful tool for the simulation of the full-size gyrotron cavity operation

On the presence of the Endangered white skate Rostroraja alba in Sardinian waters

The white skate Rostroraja alba is assessed by the International Union for Conservation of Nature as Endangered globally and is now considered rare in the Mediterranean. This species has never been recorded in Sardinian seas (central western Mediterranean), but an empty eggcase was collected on a sandy bottom off the western Sardinia coasts during the MEDiterranean International Trawl Survey (MEDITS) program in 2019. A morphometric and morphological description of the Sardinian eggcase, after a comparison with measurements from other Mediterranean and Atlantic specimens, showed it to be clearly ascribable to Rostroraja alba

Commercial sharks under scrutiny: baseline genetic distinctiveness supports structured populations of small-spotted catsharks in the Mediterranean Sea

The present study, based on microsatellite markers, describes a population genetic analysis of the small-spotted catshark Scyliorhinus canicula (Linnaeus, 1758), representing one of the most abundant and commonly caught cartilaginous fishes in the Mediterranean Sea and adjacent areas. The analyses were performed to unravel the genetic features (variability, connectivity, sex-biased dispersal) of their relative geographic populations, both at the small (around the coast of Sardinia, Western Mediterranean Sea) and at a larger spatial scale (pan-Mediterranean level and between the Atlantic Ocean and the Mediterranean Sea). Individual clustering, multivariate and variance analyses rejected the hypothesis of genetic homogeneity, with significant genetic differences between the Mediterranean and Atlantic, as well as within the Mediterranean area between the Western and Eastern basins. In details, our results seem to confirm that the Strait of Gibraltar could not represent a complete barrier to the exchange of individuals of small-spotted catshark between the Atlantic Ocean and the Mediterranean Sea. In the latter area, a complex genetic structuring for S. canicula was found. Apart from differences among the Western, Eastern and Adriatic sites, within the Western basin the small-spotted catsharks around Sardinian waters are strongly differentiated from all others (both from the eastern Tyrrhenian Sea and southernmost part of the Algerian basin) and are demographically stable. Several possible mechanisms, both biological and abiotic (e.g., migratory behavior, water fronts and oceanographic discontinuities), are discussed here to explain their peculiar characteristics. Overall, the genetic data presented, both at the local and regional level, could represent a baseline information, useful for the temporal monitoring of populations, and to assess the effects of present or future fishing/management/conservation measures