Parity in bacterial communities and resistomes: Microplastic and natural organic particles in the Tyrrhenian Sea

Petroleum-based microplastic particles (MPs) are carriers of antimicrobial resistance genes (ARGs) in aquatic environments, influencing the selection and spread of antimicrobial resistance. This research characterized MP and natural organic particle (NOP) bacterial communities and resistomes in the Tyrrhenian Sea, a region impacted by plastic pollution and climate change. MP and NOP bacterial communities were similar but different from the free-living planktonic communities. Likewise, MP and NOP ARG abundances were similar but different (higher) from the planktonic communities. MP and NOP metagenome-assembled genomes contained ARGs associated with mobile genetic elements and exhibited co-occurrence with metal resistance genes. Overall, these findings show that MPs and NOPs harbor potential pathogenic and antimicrobial resistant bacteria, which can aid in the spread of antimicrobial resistance. Further, petroleum-based MPs do not represent novel ecological niches for allochthonous bacteria; rather, they synergize with NOPs, collectively facilitating the spread of antimicrobial resistance in marine ecosystems.

Zooplankton as an indicator of the status of contamination of the Mediterranean Sea and temporal trends

Zooplankton has been intensively used as bioindicators of water pollution at global level, however, only few comprehensive studies have been conducted from the Mediterranean Sea and manly dated back to the 1970s. To redress the urgent need for updated data, this study provides information on the presence and levels of contaminants in zooplankton from the Tyrrhenian Sea. Although banned, both PCBs (46.9 ± 37.2 ng g-1) and DDT (8.9 ± 10.7 ng g-1) are still present and widespread, but their contamination appears to be a local problem and to be declining over the past 50 years. Zooplankton accumulates high levels of certain TEs, including Zn (400 ± 388 ppm) and Pb (35.3 ± 45.5 ppm), but shows intermediate concentrations of other TEs, including Cd (1.6 ± 0.9 ppm) and Hg (0.1 ± 0.1 ppm), comparing with both strongly polluted and more pristine marine habitats, which may reflect a general improvement.

Mediterranean fish communities are struggling to adapt to global warming. Evidence from the western coast of Italy

Climate change has significant impacts on marine ecosystems, resulting in disruptions in biological interactions, shifts in community composition, and changes in the physiology of fish and other marine organisms. In this study conducted in the central Mediterranean Sea, the mean temperature of the catch (MTC) was employed as an indicator to investigate the climatological factors influencing the fish community. The MTC, which utilizes species-preferred temperatures, was calculated using bottom temperature (BT) data weighted against scientific catches. The estimated MTC increasing rates were 0.01 °C year-1 for the entire community, 0.017 °C year-1 for the shelf break, and 0.004 °C year-1 for the continental slope assemblage. We found that MTC is increasing at a lower rate compared to BT, suggesting a progressive under-adaptation of the fish community that seems not fully able to keep up with the ongoing pace of warming. The study identified sea surface temperature and bottom temperature as key drivers of changes in fish community composition. Notably, the fish community composition exhibited drastic changes over the studied period, and we suggest that the MTC can be a useful index to monitor such changes within the context of the EU's climate change adaptation strategy.

Numerical investigation of the three-dimensional paths of plastic polymers in the Gulf of Naples

The high-resolution Campania Regional Ocean Model (CROM), coupled with an online Lagrangian particle tracking algorithm, is used to investigate the horizontal and vertical behavior of different (in terms of size and density) plastic polymer types during February and August 2016 in the Gulf of Naples. The transport of passive particles is evaluated based on the three-dimensional Eulerian velocity fields provided by the ocean model. The virtual particles are released in several hot spot areas in the Gulf of Naples where most of the marine debris is supposed to come from. A sensitivity analysis on the vertical sinking for negatively buoyant particles is carried out. The sinking behavior is determined by the settling velocity, which depends on the physical properties of the individual litter item as well as on the hydrodynamical features of the marine environment. Different numerical experiments are carried out to evaluate the effect of marine dynamics on three-dimensional transport.

The Genome of Varunaivibrio sulfuroxidans Strain TC8T, a Metabolically Versatile Alphaproteobacterium from the Tor Caldara Gas Vents in the Tyrrhenian Sea

Varunaivibrio sulfuroxidans type strain TC8^T is a mesophilic, facultatively anaerobic, facultatively chemolithoautotrophic alphaproteobacterium isolated from a sulfidic shallow-water marine gas vent located at Tor Caldara, Tyrrhenian Sea, Italy. V. sulfuroxidans belongs to the family Thalassospiraceae within the Alphaproteobacteria, with Magnetovibrio blakemorei as its closest relative. The genome of V. sulfuroxidans encodes the genes involved in sulfur, thiosulfate and sulfide oxidation, as well as nitrate and oxygen respiration. The genome encodes the genes involved in carbon fixation via the Calvin-Benson-Bassham cycle, in addition to genes involved in glycolysis and the TCA cycle, indicating a mixotrophic lifestyle. Genes involved in the detoxification of mercury and arsenate are also present. The genome also encodes a complete flagellar complex, one intact prophage and one CRISPR, as well as a putative DNA uptake mechanism mediated by the type IVc (aka Tad pilus) secretion system. Overall, the genome of Varunaivibrio sulfuroxidans highlights the organism's metabolic versatility, a characteristic that makes this strain well-adapted to the dynamic environmental conditions of sulfidic gas vents.

The Lush Fucales Underwater Forests off the Cilento Coast: An Overlooked Mediterranean Biodiversity Hotspot

Fucales (Phaeophyceae) are ecosystem engineers and forest-forming macroalgae whose populations are declining dramatically. In the Mediterranean Sea, Cystoseira sensu lato (s.l.)-encompassing the genera Cystoseira sensu stricto, Ericaria, and Gongolaria-is the most diverse group, and many species have been shown to be locally extinct in many areas, resulting in a shift toward structurally less complex habitats with the consequent loss of ecosystem functions and services. In this study, we report on the extensive occurrence of healthy and dense marine forests formed by Fucales in the Santa Maria di Castellabate Marine Protected Area in Cilento, Italy (Tyrrhenian Sea, Mediterranean). On a total area of 129.45 ha, 10 Cystoseira s.l. taxa were detected using a combined morphological and molecular approach, with an average cover of more than 70%. One of these taxa has been sequenced for the first time. These findings underline the high ecological value of this area as a hotspot of benthic biodiversity and highlight the importance of marine protected area management and regional monitoring programs to ensure the conservation of these valuable yet fragile coastal ecosystems.

Dietary Preferences of Loggerhead Sea Turtles (Caretta caretta) in Two Mediterranean Feeding Grounds: Does Prey Selection Change with Habitat Use throughout Their Life Cycle?

According to their life stage, the loggerhead sea turtle (Caretta caretta) is found in a wide range of habitats, from neritic to more oceanic areas. Their feeding habits are expected to change as they develop, along with habitat use. Juvenile sea turtles are hypothesized to feed on pelagic species in oceanic areas, shifting to more benthic prey during the subadult and adult stages. We analyzed the gastrointestinal content from 150 loggerhead sea turtles stranded and/or bycaught along the Adriatic coast of the Abruzzo and Molise regions (n = 89) and the Tyrrhenian coast of the Lazio and Campania regions (n = 61) from 2018 to 2021. Food items were identified to the lowest taxonomic level, and the frequency of occurrence was calculated for each taxon and most recurrent species to assess changes in prey selection during the development. The marine litter was categorized, and the frequency of occurrence was calculated for the ingestion of litter. The most recurrent taxonomic prey group recorded in the Adriatic sample was Arthropoda (94%), followed by Mollusca (63%) and Chordata (34%). In the Tyrrhenian sample, loggerhead sea turtles fed mostly on Mollusca (84%), Arthropoda (38%), and Chordata (26%). Surprisingly, the Adriatic-Tyrrhenian sample groups showed similar feeding behavior between juveniles, subadults, and adults. A similar correlation has been observed concerning the ingestion of litter. Moreover, this study confirms the opportunistic feeding behavior of loggerhead sea turtles and their high adaptability.

An integrated approach for coastal cliff susceptibility: The case study of Procida Island (southern Italy)

Procida Island, located in the Gulf of Naples (southern Italy), is characterized by steep cliffed coasts, articulated in a succession of headlands and small embayments with narrow pocket beaches, such as Ciraccio and Chiaia, often characterized by instability. In this study, a methodology for coastal cliff susceptibility assessment has been conceived based on hydraulic and geomorphological characteristics, which supported the construction of a Cliff Stability Index (CSI). The geomorphological characteristics are related to the whole cliff face, the cliff material resistance, and the cliff failure mechanisms. The hydraulic actions on the cliff are related to the wave impact which is exerted by the breaking waves once the wave run-up distance exceeds the beach width. The index takes into account the slope of the cliff, the rock strength, the wave energy at the cliff base produced by the broken wave and the presence of defence structures at the cliff base. The resulting index classification, obtained by addition of the partial sub-indices, has been compared with the observed coastal cliff evolution from 1954 to 2021.

Benthic litter in the continental slope of the Gulf of Naples (central-western Mediterranean Sea) hosts limited fouling communities but facilitates molluscan spawning

Seafloor pollution by benthic litter is an emerging phenomenon, although debris colonization by biota remains largely unexplored. We characterized the litter of the continental slope (~400-600 m) of the Gulf of Naples (Mediterranean) and investigated its fouling biota through integrative taxonomic approaches. Plastic pieces (82 %) with land-based origin (96 %) and limited sizes (10-20 cm) were the items most commonly encountered, suggesting a transfer to deep waters through floating and sinking. The majority of the items were not fouled, and the debris hosted an impoverished biota, leading to hypothesize that benthic litter supports wide communities only in shallow waters. Higher colonization rates were observed for gastropod and cephalopod eggs with no preference for materials and sizes, suggesting that even small pieces of soft plastic provide a spawning habitat for molluscs and affect species' connectivity in the deep-sea ecosystem. Holistic approaches are necessary to evaluate interactions between litter and biota.

Habitat heterogeneity: A confounding factor for the effect of pollutants on macrobenthic community in coastal waters

Discrepancies were found between Ecological Status of sediments evaluated though the analysis of macrobenthic community and chemical analyses along a heavily trafficked and contaminated maritime seaway in Tyrrhenian Sea. Chemical analyses showed some sites highly contaminated by PAHs and metals with values exceeding thresholds for Good Chemical status and representing potential toxicological risk for benthic animals. Conversely, macrobenthic communities were highly rich and diverse, with Ecological Status (through M-AMBI) Good and High at each site. Sampling depth, total organic carbon, and total nitrogen were the major factors influencing biotic indices (AMBI, M-AMBI, S, H), even if concentrations of PAHs and metals (V, As, and Fe) contributed in explaining a part of indices variability. Habitat heterogeneity of sampled sites is likely acting as a confounding factor for two reasons: (1) high variability of environmental parameters leads to high richness and diversity, to which M-AMBI is sensitive, and (2) environmental parameters explained part of the variability of indices, together with contaminants. Our results suggested the importance of considering natural variability as a fundamental step of environmental impact assessment, for the correct interpretation of biotic indices.

Signals from the deep-sea: Genetic structure, morphometric analysis, and ecological implications of Cyclothone braueri (Pisces, Gonostomatidae) early life stages in the Central Mediterranean Sea

Cyclothone braueri (Stomiiformes, Gonostomatidae) is a widely distributed fish inhabiting the mesopelagic zone of marine tropical and temperate waters. Constituting one of the largest biomasses of the ocean, C. braueri is a key element in most of the ecological processes occurring in the twilight layer. We focused on the ecological processes linked to early life stages in relation to marine pelagic environmental drivers (temperature, salinity, food availability and geostrophic currents) considering different regions of the Central Mediterranean Sea. A multivariate morphometric analysis was carried out using six parameters with the aim of discerning different larval morphotypes, while a fragment of 367 bp representing the 12S ribosomal RNA gene was used to perform molecular analyses aimed at determining the intraspecific genetic variability. Analysis highlighted two geographically distinct morphotypes not genetically discernible and related to the different nutritional conditions due to spatial heterogeneities in terms of temperature and food availability. The body depth (BD) emerged as an appropriate morphometric parameter to detect the larval condition in this species. Molecular analysis highlighted a moderate genetic divergence in the fish population, showing the recurrence of two phylogroups not geographically separated.

Cohabiting with litter: Fish and benthic assemblages in coastal habitats of a heavily urbanized area

Anthropogenic litter negatively impacts the marine environment and threatens biodiversity. At the same time, it represents a suitable substrate for the settlement of sessile species, thus potentially altering composition and structure of soft bottom benthic assemblages. By using a Remotely Operated Vehicle (ROV), we hereby investigated patterns of abundance, distribution, and origin of benthic litter in three subtidal habitats of a heavily urbanized area and tested whether litter distribution related to patterns of fish and mega- and macro-benthic diversity. Litter accumulation mostly occurred on soft bottoms, while rocky substrata were the least affected, albeit being particularly threatened by sea-based pollution. As expected, the highest biodiversity was observed on rocky bottoms, hosting notable biogenic formations (Cladocora caespitosa, Leptogorgia sarmentosa) despite the area is historically affected by anthropogenic activities. No correlation was found between biota and marine litter, suggesting that litter does not apparently influence biodiversity and distribution of the investigated assemblages.

New Parasite Records for the Sunfish Mola mola in the Mediterranean Sea and Their Potential Use as Biological Tags for Long-Distance Host Migration

Studies describing the parasite fauna of sunfish species from the Mediterranean Sea are to date limited, despite information gained through parasitological examination may reveal unknown ecological and biological aspects of both hosts and parasites. Moreover, recent molecular studies on sunfish taxonomy revealed the presence of two species belonging to the genus Mola in the Mediterranean basin, namely M. mola and M. alexandrini. These two fish taxa have long been synonymized or confused among them, which implies that the majority of the studies carried out so far reported the parasites infecting both species under a single host species, generally referred to as M. mola. We hereby investigated the parasite fauna of a 43 cm long M. mola specimen from the Mediterranean Sea, whose identification was confirmed by molecular tool, and provided the first evidence of the occurrence of the nematode Anisakis simplex (s.s.) and of the cestode Gymnorhynchus isuri in Mola species anywhere. The use of helminth species as biological tags for the sunfish is also discussed.

Spatial and temporal analysis of meso- and microplastic pollution in the Ligurian and Tyrrhenian Seas

Areas like the Mediterranean coastlines, which have high population density, represent locations of high pollution risk for surrounding environments. Thus, this study aims to compare data on the abundance, size, and composition of buoyant plastic particles collected during two weeks in 2019 in the Ligurian and Tyrrhenian Seas with data from 2018. The results from 2019 show average meso- and microplastic particle concentrations of 255,865 ± 841,221 particles km^-2, or 394.19 ± 760.87 g km^-2; values which differ significantly from those reported in 2018. Microplastic particles accounted for 88.7% of the sample; the majority of which had a size range being between 1 and 2.5 mm. These data are an important milestone for long-term monitoring of the highly variable plastic pollution levels within this region; showing overlaps in zones of pollutant accumulation in addition to increased overall concentrations of plastic particles compared to previous data.

Distribution and Characterization of Deep Rhodolith Beds off the Campania coast (SW Italy, Mediterranean Sea)

Rhodolith beds (RBs) are bioconstructions characterized by coralline algae, which provide habitat for several associated species. Mediterranean RBs are usually located in the mesophotic zone (below 40 m), and thus are frequently remote and unexplored. Recently, the importance and vulnerability of these habitats have been recognized by the European Community and more attention has been drawn to their investigation and conservation. This study reports the results of an extensive monitoring program, carried out within the Marine Strategy Framework Directive (2008/56/EC), in six sites off the Campania coast (Italy, Mediterranean Sea). New insights were given into the distribution, cover, vitality (i.e., live/dead rhodolith ratio), structural complexity, and coralline algae composition of RBs. Remotely operated vehicles (ROV) investigations allowed the description of several RBs, and the discovery of a RB with rhodolith cover >65% offshore the Capri Island. Only two sites (Secchitiello and Punta Campanella) showed a very low mean cover of live rhodoliths (<10%); hence, not being classifiable as RBs. The collected rhodoliths were mostly small pralines (~2 cm), spheroidal to ellipsoidal, with growth-forms ranging from encrusting/warty to fruticose/lumpy. Coralline algae identification revealed a high diversity within each bed, with a total of 13 identified taxa. The genus Lithothamnion dominated all sites, and Phymatolithon calcareum and Lithothamnion corallioides, protected by the Habitats Directive (92/43/EEC), were detected in all RBs.

Plastics occurrence in juveniles of Engraulis encrasicolus and Sardina pilchardus in the Southern Tyrrhenian Sea

We report the presence of microplastics on the external surface and in the gastrointestinal tract of white late-larval and juvenile stages (fry) of clupeid fishes caught in the Southern Tyrrhenian Sea. The average highest number of plastics debris was recorded on Sardina pilchardus (0.53 items/specimen); a lower average number of items was observed for Engraulis encrasicolus (0.26 items/specimen). The plastics were characterized by fibers that differed in shape, colour and composition. Polyester, polypropylene, polyacrylonitrile, polyethylene, polyamide, nylon, rayon and polyurethane segments were detected by Raman and FTIR spectroscopies. Traces of organic components and dyes, compounds that are generally included in the polymer matrix to modify its base properties, were also identified on microplastics. Our results raise concerns for the potential transfer of synthetic materials through the marine food web and into humans, given the prominent role of S. pilchardus and E. encrasicolus within the food web as main food source for many marine species.

Types, occurrence and distribution of microplastics in sediments from the northern Tyrrhenian Sea

This is the first survey to investigate microplastic contamination in the Northern Tyrrhenian seafloor, along a 31 km-long transect from the port of Piombino (Tuscany) to the port of Portoferraio (Elba Island). Plastics extracted from 58 sediment samples were counted and identified by Fourier-transform infrared spectroscopy (FTIR). Plastic pollution occurred in sites closer to ports as well as in offshore stations. Microplastics (1-5 mm) accounted for over 80% of particles. For all samples, the dominant microplastic type was filaments, followed by fragments and films. Six polymers were identified: nylon, polyurethane, polyethylene, and polyethylene terephtalate were the most common. This part of the Tyrrhenian Sea is a busy shipping route connecting the mainland to the Elba Island, with thousands cargo and passenger ships passing by per year. Our data constitute a baseline for microplastic research in the Tyrrhenian seafloor.

The Mediterranean Mussel (Mytilus galloprovincialis) as Intermediate Host for the Anisakid Sulcascaris sulcata (Nematoda), a Pathogen Parasite of the Mediterranean Loggerhead Turtle (Caretta caretta)

Sulcascaris sulcata (Anisakidae), a pathogenic nematode of sea turtles, may cause ulcerous gastritis with different degrees of severity. Previous studies demonstrated a high prevalence of infection in the Mediterranean loggerhead turtle (Caretta caretta), although no data on the potential intermediate hosts of this nematode has been published thus far from the Mediterranean basin. Here, using molecular analyses, we demonstrated that the cross sections of nematode larvae observed histologically in Mediterranean mussels (Mytilus galloprovincialis) collected from a farm along the Tyrrhenian coast of southern Italy belong to S. sulcata. The BLAST analysis of sequences at the ITS2 region of rDNA and mtDNA cox2 gene loci here obtained from samples of two Mediterranean mussels containing nematode larvae showed 100% homology with those at the same gene loci from the adults of S. sulcata collected from the Mediterranean Sea and deposited in GenBank. To our knowledge, this study is the first to present data on a potential intermediate host of S. sulcata in the Mediterranean basin and to report a nematode parasite from the Mediterranean mussel.

Epidemiology of blood flukes (Digenea: Spirorchiidae) in sea turtles from Tyrrhenian and Adriatic Seas, off Italy

Background

The Spirorchiidae is a family of blood flukes parasitizing turtles. Spirorchiids may cause a wide range of inflammatory reactions in the vascular system of their host being frequently implicated with stranding and death of sea turtles worldwide. Recent studies revealed the presence of two spirorchiid species in the Mediterranean basin. Our study presents comparative epidemiological data of spirorchiid infections in loggerhead turtles (Caretta caretta) stranded during an eight-year period from Adriatic and Tyrrhenian Seas, and the first report of Neospirorchis Neogen-11 in a green turtle (Chelonia mydas).

Methods

We screened a total of 319 carcasses of loggerhead turtles stranded from January 2011 to December 2018 along the Tyrrhenian coast (n = 111) and the north-western Adriatic coast (n = 208) of Italy using traditional (copromicroscopy and histopathology) and molecular assays. Three green turtles from the Tyrrhenian coast were also included in the study.

Results

A total of 56 (17.5%) loggerhead turtles and one green turtle (33.3%) were found to be infected with spirorchiid flukes. Amplification, sequencing of the ITS2 region of the ribosomal RNA gene cluster and BLAST analysis confirmed the presence of Hapalotrema mistroides and Neospirorchis Neogen-11 in 51 (16.0%) and 24 (7.5%) loggerhead turtles, respectively, and Neospirorchis Neogen-11 in an infected green turtle. Differences in prevalence of infection between the two sampling areas were found.

Conclusions

The risk of spirorchiid infection in the Tyrrhenian Sea is lower than in the Adriatic Sea and in general the risk of infection in the Mediterranean is lower than in other geographical locations. Differences in the prevalence of infection between the two sampling areas were related to the differences of regional habitats supporting different abundance of spirorchiid intermediate hosts. A systematic monitoring to evaluate the progress of the infection is recommended, as well as studies on the occurrence and distribution of spirorchiid species from other Mediterranean areas.

First record of 'plasticrusts' and 'pyroplastic' from the Mediterranean Sea

We report the presence of 'plasticrusts' and 'pyroplastic' from coastal habitats in Giglio island, Tyrrhenian Sea, Italy. These novel plastic debris types have only recently been described for the first time from Madeira island (NE Atlantic Ocean) and the United Kingdom, respectively. While 'plasticrusts' are generated by sea waves smashing plastic debris against intertidal rocks, 'pyroplastic' derives from (un)deliberately burnt plastic waste. Using Fourier-transform infrared (FTIR) spectroscopy, we identified the 'plasticrust' material as polyethylene (PE) and the 'pyroplastic' material as polyethylene terephthalate (PET). These polymers are widely used in everyday products and, therefore, contribute heavily to plastic pollution in aquatic and terrestrial environments worldwide. Furthermore, our field surveys suggest that 'plasticrust' abundance is related to wave-exposure and that the 'pyroplastic' derived from beverage bottles which we frequently found along the Giglio coast. Overall, our findings corroborate the notion that 'plasticrusts' and 'pyroplastic' are common debris types in marine coastal habitats.

First record of microplastics ingestion by European hake MERLUCCIUS MERLUCCIUS from the Tyrrhenian Sicilian coast (Central Mediterranean Sea)

A sample of 67 European hake Merluccius merluccius were examined to highlight the ingestion of microplastics in the Tyrrhenian Sea. In all samples, 31 black fibres were found in the stomach contents corresponding to 46.3% of the specimens. The data presented here could be important for the implementation of the EU Marine Strategy Framework Directive in Mediterranean waters.

Pathways of inorganic and organic contaminants from land to deep sea: The case study of the Gulf of Cagliari (W Tyrrhenian Sea)

In continental margins, canyons appear to act as natural conduits of sediments and organic matter from the shelf to deep basins, providing an efficient physical pathway for transport and accumulation of particles with their associated land-produced contaminants. However, these mechanisms have not been yet sufficiently explored by geochemical markers. The continental slope of the south Sardinia has been used as a natural laboratory for investigating mechanisms and times of transfer dynamics of contaminants from land to sea and from shelf to deep sea through an articulated system of submarine canyons. Here, dynamics of contaminants have been investigated in a pilot area of the central Mediterranean basin (Gulf of Cagliari, S Sardinia) where important industrial plants are sited since beginning of the last century. Five sediment cores dated by ²¹⁰Pb and ¹³⁷Cs reveal: i) a complex dynamics of organic and inorganic contaminants from point source areas on land to the deep sea and ii) a crucial role played by canyons and bottom morphology as primary pathway conveying sediments and associated contaminants from sources to very far deep sea environments. In particular, this study provides new integrated tools to properly understand mechanisms of connection between coastal sectors and deep sea. This is challenging mostly in regions where coastal pollution could represent critical threats for larger areas of the Mediterranean Sea.

Ecological Succession of Sulfur-Oxidizing Epsilon- and Gammaproteobacteria During Colonization of a Shallow-Water Gas Vent

In this study, we integrated geochemical measurements, microbial diversity surveys and physiological characterization of laboratory strains to investigate substrate-attached filamentous microbial biofilms at Tor Caldara, a shallow-water gas vent in the Tyrrhenian Sea. At this site, the venting gases are mainly composed of CO₂ and H₂S and the temperature at the emissions is the same as that of the surrounding water. To investigate the composition of the total and active fraction of the Tor Caldara biofilm communities, we collected established and newly formed filaments and we sequenced the 16S rRNA genes (DNA) and the 16S rRNA transcripts (cDNA). Chemoautotrophic sulfur-oxidizing members of the Gammaproteobacteria (predominantly Thiotrichales) dominate the active fraction of the established microbial filaments, while Epsilonproteobacteria (predominantly Sulfurovum spp.) are more prevalent in the young filaments. This indicates a succession of the two communities, possibly in response to age, sulfide and oxygen concentrations. Growth experiments with representative laboratory strains in sulfide gradient medium revealed that Sulfurovum riftiae (Epsilonproteobacteria) grew closer to the sulfide source than Thiomicrospira sp. (Gammaproteobacteria, Thiotrichales). Overall, our findings show that sulfur-oxidizing Epsilonproteobacteria are the dominant pioneer colonizers of the Tor Caldara biofilm communities and that Gammaproteobacteria become prevalent once the community is established. This succession pattern appears to be driven - among other factors - by the adaptation of Epsilon- and Gammaproteobacteria to different sulfide concentrations.

Plastic levels in sediments closed to Cecina river estuary (Tuscany, Italy)

This study focuses on plastic distribution levels (shape, size, colour, type) in sediments from the coastal area of Cecina (Tuscany, Italy). Samples are collected in three sampling stations along six transect settled randomly along the shoreline and along the final tract of the Cecina river. Recorded plastic size ranges within 62.51-13,462 μm (average values 1591 ± 837 μm). Microplastics (<5000 μm) represent over than 97% of the total even if mesoplastics (5000-25,000 μm) are also recorded (2%). Over than 60% of recorded plastic items are higher than 500 μm. Measured levels range within 72 (ST2)-191 (ST4) items/kg d.w. Fragment > Fiber > Granule in each of the tested sampling site. Plastic litter levels recorded in study evidence low pollution compared to the existing literature supporting the occurrence of good environmental levels in Cecina coastline for the "Marine litter" descriptor.

Underwater noise assessment outside harbor areas: The case of Port of Civitavecchia, northern Tyrrhenian Sea, Italy

Underwater noise assessment is particularly important in coastal areas where a wide range of natural and anthropogenic sounds generate complex and variable soundscapes. In the last century, the number and size of noise sources has increased significantly, thereby increasing the ocean's background noise. Shipping is the main source of lower-frequency underwater noises (<500 Hz). This research aimed to provide an initial assessment of underwater noise levels in a coastal area of the northern Tyrrhenian Sea (Italy) using short-term recordings. Spatial and temporal variations in the noise level, and the type and number of ships sailing through the port were recorded. A significant correlation was found between ferry boats and sound pressure levels, indicating their role as a prevalent source of low frequency underwater noise in the project area. This research could provide the baseline for implementation of distribution and point-source underwater noise models that are required for sustainable coastal management.

Seasonal Trend of PAHs Concentrations in Farmed Mussels from the Coastal Areas of the Naples, Italy

This paper reports on the results about the chemical pollution pressure in the Gulf of Naples and nearby coastal areas. Farmed mussels were analysed for the presence of polycyclic aromatic hydrocarbons (PAHs). The results documented a decreasing trend in the PAHs levels respect to the past years. The Bay of Pozzuoli remains as the most contaminated site within the Lucrino area with the highest reported number of samples exceeding the benzo(a)pyrene and PAHs sum limits. All the samples with concentrations above the European regulatory limit were collected in the winter period illustrating a seasonal trend of PAHs distribution in mussels during the 4 years investigated.

Plastic litter in sediments from the coasts of south Tuscany (Tyrrhenian Sea)

This study estimated the total loads of plastic litter (macro-meso- and micro-plastics) in sediments from a wide stretch of marine and coastal environment of Tyrrhenian Sea. The prevailing category of debris was microplastic. The results obtained, in terms of average amount of microplastic per kilogram of dry sediment, are in agreement with data reported by various Authors internationally. The study area resulted to be uniform for plastic items levels. Particularly evident was the influence of a flood, occurred in November 2012 in Talamone, on sediments collected at the harbour of this locality: in this area, a difference in levels and quality of plastic debris, attributable to periods before and after the flood, was observed in sediments. In addition to focusing on the effect of this phenomenon, this study gives an important overview, for what concerns the presence of plastic litter, of a significant naturalistic area.

Spatial variations in feeding habits and trophic levels of two small pelagic fish species in the central Mediterranean Sea

Trophic ecology of adults of European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) was examined and compared among various regions of central Mediterranean Sea. Carbon and nitrogen stable isotope analyses (δ(13)C and δ(15)N) were adopted as a tool to determine changes in feeding behaviour of adults of sardines and anchovies. In the study period (summer) a clear geographical pattern was recognized in the isotopic composition of both species, with an increasing trend northward. The highest variations in isotopic signal were linked to the geographical positions of the samples and, especially, between pairs of areas: South Sicily/South Campania and Gulf of Gaeta/South Elba. Higher isotope values were found in the anchovies and sardines caught in northern Tyrrhenian Sea, while lower values were mostly estimated in the southern region. Higher carbon and nitrogen isotopes may reflect a more coastal behaviour of both species, being (13)C-enriched source from benthic primary producers in addition to phytoplankton. Variations in the nitrogen isotope ratio may reflect not only differences in the trophic level of prey species, but also variations in the baseline level of food webs. Our results support the hypothesis that feeding behaviour of both species is directly or indirectly influenced by local factors, or by resource partitioning based on zooplankton size. Findings can supply knowledge needed for improving fish stock management and promoting plans able to take into account also local ecosystem analysis.

Relationships between trace elements in Posidonia oceanica shoots and in sediment fractions along Latium coasts (northwestern Mediterranean Sea)

The Mediterranean endemic seagrass Posidonia oceanica is widely used as a sensitive bioindicator of trace elements (TEs) in the coastal environment. Therefore, a bulk of data exist on TE levels from impacted versus unpolluted sites while only recent studies started comparing TE accumulation in plant compartments versus both water column and sediment characteristics. In this study, six TEs (As, Cd, Cr, Cu, Ni, Pb) were analyzed in P. oceanica shoots related to depth (-10 and -20 m) and to TE concentrations in the different grain size fractions of the sediment, from two Sites of Community interest (SIC) in the central Tyrrhenian Sea. TE concentrations in both shoots and sediment were generally low, except for Cr. Cu was the only element showing significantly different concentrations at the two sites while As differed significantly between samples taken at different depths. TE concentrations in the unsieved sediment were found uncorrelated to TEs in shoots except for the important nutrient Cu (positive correlation). The finest sediment fractions were enriched in TEs and significantly correlated to Cd, Cr, Cu, and Ni concentrations in the shoots.

The "one-out, all-out" principle entails the risk of imposing unnecessary restoration costs: a study case in two Mediterranean coastal lakes

The Water Framework Directive uses the "one-out, all-out" principle in assessing water bodies (i.e., the worst status of the elements used in the assessment determines the final status of the water body). In this study, we assessed the ecological status of two coastal lakes in Italy. Indices for all biological quality elements used in transitional waters from the Italian legislation and other European countries were employed and compared. Based on our analyses, the two lakes require restoration, despite the lush harbor seagrass beds, articulated macrobenthic communities and rich fish fauna. The "one-out, all-out" principle tends to inflate Type I errors, i.e., concludes that a water body is below the "good" status even if the water body actually has a "good" status. This may cause additional restoration costs where they are not necessarily needed. The results from this study strongly support the need for alternative approaches to the "one-out, all-out" principle.

Presence of plastic debris in loggerhead turtle stranded along the Tuscany coasts of the Pelagos Sanctuary for Mediterranean Marine Mammals (Italy)

This work evaluated the presence and the frequency of occurrence of marine litter in the gastrointestinal tract of 31 Caretta caretta found stranded or accidentally bycaught in the North Tyrrhenian Sea. Marine debris were present in 71% of specimens and were subdivided in different categories according to Fulmar Protocol (OSPAR 2008). The main type of marine debris found was user plastic, with the main occurrence of sheetlike user plastic. The small juveniles showed a mean±SD of marine debris items of 19.00±23.84, while the adult specimens showed higher values of marine litter if compared with the juveniles (26.87±35.85). The occurrence of marine debris observed in this work confirms the high impact of marine debris in the Mediterranean Sea in respect to other seas and oceans, and highlights the importance of Caretta caretta as good indicator for marine litter in the Marine Strategy Framework Directive (MSFD) of European Union.