Tetrodotoxins (TTXs) are potent neurotoxins named after the Tetraodontidae fish family. The ingestion of TTX-contaminated flesh can cause neurotoxic symptoms and can lead to death. In 2017 symptoms ...the European Food Safety Authority (EFSA) recognized the threat to food safety resulting from TTX exposure via food consumption and, thus, proposed a safety limit of 44 μg/kg of TTX in marine gastropods and bivalves. To date, however, TTXs have not yet been included in the list of biotoxins to be monitored within the European Union, even though, in a few cases, levels of TTX found were higher than the EFSA limit. The origin of TTX production is debated and the roles of both biotic and abiotic factors on TTX-mediated toxic events remain unclear. In order to meet these knowledge requests the present study was aimed to investigate the role of seawater temperature, pH, water conductivity, and oxygen saturation, along with the marine phytoplankton community and the bacterial community of mussels and oysters on the accumulation of TTX and analogues in the bivalves. Abiotic parameters were measured by means of a multi-parametric probe, phytoplankton community was analyzed by optic microscopy while microbial community was described by amplicon metataxonomic sequencing, TTXs concentration in the collected matrices were measured by HILIC-MS/MS.
A possible role of seawater pH and temperature, among the investigated abiotic factors, in regulating the occurrence of TTXs was found. Regarding biotic variables, a possible influence of Vibrio, Shewanella and Flavobacteriaceae in the occurrence of TTXs was found. Concurrently, Prorocentrum cordatum cell numbers were correlated to the incidence of TTX in mussels. The results herein collected suggest that environmental variables play a consistent part in the occurrence of TTX in the edible bivalve habitats, and there are also indications of a potential role played by specific bacteria taxa in association with phytoplankton.
Display omitted
•Temperature and pH involved in the occurrence of tetrodotoxin in marine bivalves.•Vibrio, Shewanella and Flavobacteriaceae are potentially related to TTXs occurrence.•Prorocentrum cordatum still suspected to be involved in tetrodotoxin production.
Interaction and mobility have attracted much interest in research within scholarly fields as different as archaeology, history, and more broadly the humanities. Critically assessing some of the most ...widespread views on interaction and its social impact, this book proposes an innovative perspective which combines radical social theory and currently burgeoning network methodologies. Through an in-depth analysis of a wealth of data often difficult to access, and illustrated by many diagrams and maps, the book highlights connections and their social implications at different scales ranging from the individual settlement to the Mediterranean. The resulting diachronic narrative explores social and economic trajectories over some seven centuries and sheds new light on the broad historical trends affecting the life of people living around the Middle Sea.
The dynamics of hydrographic and biogeochemical properties in a Northwestern coastal area of the Adriatic Sea were investigated. The time series data from continuous observation (2007–2022) allowed ...the investigation of annual trends and seasonal cycles along a coastal transect influenced by local river discharge. Various statistical models were used to investigate water temperature, salinity, chlorophyll a, dissolved organic, inorganic and particulate nutrients, precipitation and river discharge. It was found that the local river discharge regime played an essential role in interannual, and seasonal biogeochemical dynamics associated with global climate change in the Mediterranean region. A significant trend towards oligotrophic conditions was detected, as evidenced by the downward trend in the river mouth and on the sea of chlorophyll a (−0.2 μg L−1 in the sea), dissolved organic and inorganic nitrogen and phosphorus (i.e., −0.43 μM yr−1 of DON in the sea and −6.67 of DIN μM yr−1 in the river mouth or −0.07 μM yr−1 of DOP and −0.02 μM yr−1 of DIP in the river mouth) and silicate (−2.47 μM yr−1 in the river mouth) concentrations. Salinity showed a long-term increase in the sea (0.08 yr−1), corresponding to a significant decrease in water discharge from the local river (−0.27 m3 s−1 yr−1) and precipitation (−0.06 mm yr−1). The dissolved organic and inorganic nutrients highlighted a different seasonal accumulation under the river runoff regime. The nutrient enrichment was predominantly driven by river contribution. Data analysis showed that the coastal biogeochemical properties dynamics were mostly influenced by river discharge and precipitation regimes, which in turn are driven by climate change variability in the North-western Adriatic Sea.
Display omitted
•Time series data allowed assessing variability of biogeochemical properties in coastal waters.•Role of the minor river inputs on interannual trend and seasonal cycles of biogeochemical properties.•Confirmed oligotrophic trends in NW Adriatic coastal waters of organic and inorganic N and P.•Organic N and P originate from river runoff input than regeneration production.•Runoff variability and climate changes as drivers of biogeochemical dynamics in Adriatic Sea.
The sustainability of most Mediterranean fisheries is heavily compromised, suggesting the need for an effective policy response to preserve both profitability of fleets and fish stocks in the long ...run. This study focuses on the Italian small pelagic fleet in the Adriatic Sea. More specifically, we focus on anchovies and sardines' stocks, which account for most of the total catches in the area in terms of landed weight. We build an optimization model aimed at estimating the discounted Maximum Economic Yield (MEY) of this fishery under selected policy scenarios ranging from effort limitations to total allowable catch (TAC) management. The model allows us to compare the bioeconomic performances of the fishery over a time span of 10 years. The results outline a trade-off between biological and economic policy targets, as well as an efficiency gap among fishing gears. This gap ultimately leads to an uneven distribution of economic benefits under restrictive policy scenarios.
•Different fishing gear efficiency levels cause unequitable distribution of profits.•Effort limitation policies enable higher profitability of the fishery.•Total allowable catches allow higher biomass levels.•A trade-off exists between biological and economic policy targets.
•Strong plant influence on (elevated) 226Ra and 238U activities in soil.•Weak plant influence on 40K and 232Th activities in soil.•Distance from TPP + wind direction the most influential for 40K, ...232Th, 226Ra, 238U.•Strongest plant impact up to 1 km distance from the plant.•Plant impact probable up to 10 km distance or more, but relatively weak.
Massic activities of 40K, 226Ra, 232Th, 238U, and 137Cs were determined by gamma-spectrometry in soil samples collected around Plomin thermal power plant (TPP) at three radial distances from the plant, along the profile in the prevailing wind direction within 1 km distance from the plant, and at three soil depths. Spatial distribution of radionuclides in topsoil and subsoil around Plomin TPP and its dependence on distance from the plant, soil depth, and wind direction were studied. The purpose was to determine the influence of fly ash, bottom ash, and coal from Plomin TPP on surrounding soil and to establish a baseline for radionuclides’ activities around the plant. Strong plant impact on 226Ra and 238U (elevated) activities in soil was determined. Probable impact on 40K and 232Th was also determined, but it was relatively weak. The strongest impact is generally within 1 km distance from the plant, but it may reach the distances of 10 km or more although with much weaker intensity. The strongest impact is recorded in areas SW and NW from the plant, respectively. The most influential parameters for distribution of 40K, 226Ra, 232Th, and 238U were distance from the plant and wind direction. The most influential parameters for 137Cs distribution were soil depth and precipitation pattern. NE wind (bora) and SE wind (sirocco) influence the most on deposition of particles from the plant on the surrounding soil.
We depict the relative sea-level rise scenarios for the year 2100 from four areas of the Italian peninsula. Our estimates are based on the Rahmstorf (2007) and IPCC-AR5 reports 2013 for the RCP-8.5 ...scenarios (www.ipcc.ch) of climate change, adjusted for the rates of vertical land movements (isostasy and tectonics). These latter are inferred from the elevation of MIS 5.5 deposits and from late Holocene sea-level indicators, matched against sea-level predictions for the same periods using the glacio-hydro-isostatic model of Lambeck et al. (2011). We focus on a variety of tectonic settings: the subsiding North Adriatic coast (including the Venice lagoon), two tectonically stable Sardinia coastal plains (Oristano and Cagliari), and the slightly uplifting Taranto coastal plain, in Apulia. Maps of flooding scenarios are shown on high-resolution Digital Terrain Models mostly based on Lidar data. The expected relative sea-level rise by 2100 will change dramatically the present-day morphology, potentially flooding up to about 5500 km2 of coastal plains at elevations close to present-day sea level.
The subsequent loss of land will impact the environment and local infrastructures, suggesting land planners and decision makers to take into account these scenarios for a cognizant coastal management. Our method developed for the Italian coast can be applied worldwide in other coastal areas expected to be affected by marine ingression due to global climate change.
Recreational boats are a dominant source of underwater noise in coastal areas, but reliable boat noise assessment is generally lacking. Here the Underwater Radiated Noise (URN) of seven recreational ...and small fishing boats moving at two different speeds was measured in the shallow waters of the Cres-Lošinj Natura 2000 SCI (Croatia). Measurements were undertaken considering the internationally recognized standards and published guidelines for shallow waters. URN was provided in 1/3 octave band spectra and in narrow band spectra, to highlight the tonal components. Engine power and type rather than the boat length and design result to be more predictive of URN. Highest speeds induce highest noise levels only in a very limited frequency range and different boats with similar speed but different engines show a shift in the spectra. Relevance of the achieved results for the tested area is further discussed.
•Underwater Radiated Noise of seven boat types was measured in a shallow environment.•Underwater Radiated Noise was provided as 1/3 octave and narrow band spectra.•The spectra show strong tonal components.•Boats with similar speed but different engines show different noise emissions.•Highest speed induces highest noise levels only in a very limited frequency range.
The Kvarner area is located in the Northern Adriatic Sea, between the south-east Istrian Swell, the Rijeka coast and the Croatian sea boundary. It includes several islands, representing the ...outcropping parts of anticlines produced by the compressional/transpressional deformation of the External Dinaric Chain. An extensive 2D seismic dataset, acquired for hydrocarbon exploration and calibrated by wells, allowed us to reconstruct the time structural maps in Kvarner and unravel its regional fault pattern. The Dinaric compressional phase affected the area in the Late Cretaceous, with both thin- and thick-skinned tectonics related to Adriatic Carbonate Platform (AdCP) succession rigidity. Structural highs facing the Kvarner offshore from the Istrian inland continue through the Kvarner and Rijeka bays and outcrop in the islands. These anticlines, originating from the pre-Messinian Dinaric thrust system, were reactivated by the post-Messinian transpression, as testified by flower structures. Several sharp valleys represent two main low structural lineaments, developed between the anticlines and partially incised during the Messinian. They were observed throughout the entire studied area, specifically in the western part of the bays, where the lineament continues through the valleys and penetrates the SW-Istria land. Data show that the Messinian erosional effect and sedimentation patterns were influenced and driven by the morphology of older structures produced by the Dinaric compressional phase.
•Thin-and thick-skinned tectonics is present in the External Dinarides.•Structures of Kvarner Islands continue in the Istrian peninsula through Kvarner offshore.•Sharp valleys are filled by a prograding clinoform system bounded by two major unconformities.•Older tectonic structures played an important role in recent geodynamics of External Dinarides.
This is the first survey to investigate the occurrence and extent of microplastic contamination in sediments collected along a coast-open sea 140km-long transect in the Central Adriatic Sea. Plastic ...debris extracted from 64 samples of sediments were counted, weighted and identified by Fourier-transform infrared spectroscopy (FT-IR). Several types of plastic particles were observed in 100% of the stations. Plastic particles ranged from 1 to 30mm in length. The primary shape types by number were filaments (69.3%), followed by fragments (16.4%), and film (14.3%). Microplastics (1–5mm) accounted for 65.1% of debris, mesoplastics (5–20mm) made up 30.3% of total amount, while macro debris (>20mm) accounted for 4.6% of total plastics collected. Identification through FT-IR spectroscopy evidenced the presence of 6 polymer types: the majority of plastic debris were nylon, polyethylene and ethylene vinyl alcohol copolymer. Our data are a baseline for microplastic research in the Adriatic Sea.
•Sediments of the Adriatic Sea were sampled in 2015 to assess plastics quantity and type.•Microplastics (1–5mm) accounted for 65.1% % of debris•The primary shape types by number were filaments (69.3%).•FT-IR spectroscopy evidenced the presence of 6 plastic types.•The most common materials were nylon and polyethylene.
The transport of a variety of pollutants from agricultural, industrial and urbanised areas makes rivers major contributors to the contamination of coastal marine environments. Too little is known of ...their role in carrying pathogens to the coast. We used DNA-based metabarcoding data to describe the microbial community composition in seawater and sediment collected in front of the estuary of the Tronto, the Chienti and the Esino, three Italian rivers with different pollution levels that empty into the north-central Adriatic Sea, and to detect and measure within these communities the relative abundance of microbial pollutants, including traditional faecal indicators and alternative faecal and sewage-associated pollutants. We then applied the FORENSIC algorithm to distinguish human from non-human sources of microbial pollution and FAPROTAX to map prokaryotic clades to established metabolic or other ecologically relevant functions. Finally, we searched the dataset for other common pathogenic taxa. Seawater and sediment contained numerous potentially pathogenic bacteria, mainly faecal and sewage-associated. The samples collected in front of the Tronto estuary showed the highest level of contamination, likely sewage-associated. The pathogenic signature showed a weak but positive correlation with some nutrients and strong correlations with some polycyclic aromatic hydrocarbons. This study confirms that rivers transport pathogenic bacteria to the coastal sea and highlights the value of expanding the use of HTS data, source tracking and functional identification tools to detect microbial pollutants and identify their sources with a view to gaining a better understanding of the pathways of sewage-associated discharges to the sea.
Display omitted
•Rivers can be major contributors to the pollution of coastal marine environments.•The role of rivers in transporting pathogens to the coast still remain unanswered.•Traditional, alternative and sewage-related faecal pollutants were found.•Both seawater and sediment were presumptively contaminated by potential pathogens.•Correlations between pathogenic signature and anthropogenic impact were found.
Faecal and sewage-associated bacteria released by coastal rivers make these waterways a source of potentially pathogenic bacteria in the coastal sea.
PDF
