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.
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•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 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.
The main strategy was to maintain the sea route from the northernmost point of the Adriatic to the Levant, and to introduce the necessary legal, commercial, and administrative practices modelled upon ...its own. During the 13th and 14th centuries Venice worked on gaining military and economic control over the Eastern Adriatic and “prepared the ground” for its later long dominance in that area. In this period, from Venetian perspective, the cities were primarily strategic and exchange points – and were increasingly perceived as the natural hub of connections between the Mediterranean and Central Europe or the West and the Levant. The infrastructures that supported the Venetian long-distance trade in the 13th and 14th centuries were related to security, equipment, and the possibility of transit, as well as supplying enough manpower on the way.
High-resolution stable-isotope ratio data (δ18O, δ13C) were used to study growth strategies of two bivalve species, Pecten jacobaeus (calcitic shell) and Glycymeris pilosa (aragonitic shell) from the ...North Adriatic Sea. The principal objectives of this study were to identify the period of the year when the growth line is formed in the shell of two target species, to identify the main growing season of these two species, to identify the environmental drivers of shell growth, and to evaluate the potential applicability of δ18O and δ13C values for the reconstruction of environmental variability. Samples were collected from the North Adriatic Sea by commercial bean trawl (P. jacobaeus, December 2013 and January 2014, N=4) and SCUBA diver (Glycymeris pilosa, March 2016, N=3). Samples for the oxygen (δ18O) and carbon (δ13C) isotope composition of the calcium carbonate were collected by drilling the outer shell layer across several annual cycles. Temporal and spatial temperature and salinity values inside the investigated area were simulated using the 3D numerical ocean model - ROMS. The δ18O cycles corresponded to the number of seasonal growth marks observed on the external shell surface of both target species, thereby confirming the annual periodicity of these growth patterns. In February 2012, extreme cooling of the water column accompanied by dense water formation occurred in the Adriatic Sea - an event recorded by P. jacobaeus shells. This study indicates that P. jacobaeus and G. pilosa have contrasting shell growth strategies. Pecten jacobaeus grows during winter and slows shell growth during the warmest part of the year, and thereby may be an interesting archive for winter conditions. Due to its longevity and continuous growth during the warmest part of the year, G. pilosa is a promising archive for the reconstruction of summer seawater temperatures.
•Pecten jacobaeus and Glycymeris pilosa from the North Adriatic have contrasting growth strategies•Growth slowdown of P. jacobaeus occurred during summer while G. pilosa grew at slowest rates during winter•Both species formed growth lines in fall, indicating that sea temperature is not the only factor regulating shell growth•Studied species can be used as archives of environmental variability in the Adriatic and Mediterranean Seas
SUMMARY
The present-day sea-level variations and vertical movements in the northern Adriatic Sea and in the highly vulnerable Venetian Lagoon result from a number of simultaneously operating ...contributions. These include Glacial Isostatic Adjustment (GIA), the global, long-term process arising from interactions between the cryosphere, the solid Earth and the oceans in response to the melting of continental ice sheets. Although the GIA contribution in northern Adriatic Sea has been the subject of various investigations so far, significant uncertainties still exist, especially related to the extent and chronology of the Würm Alpine ice sheet and to the rheological profile of the mantle. Here, taking advantage of the recent publication of updated deglaciation chronologies for the far field late-Pleistocene ice sheets and for the near-field alpine ice complex, we produce up-to-date estimates of the present-day rates of GIA-induced relative sea-level variations and vertical displacements in the Venetian Lagoon and in the northern Adriatic Sea, which are compared with GNSS and tide-gauge observations. From high-resolution numerical simulations, we find that GIA is responsible for a complex pattern of geodetic signals across the Po plain and the northern Adriatic Sea. The modeled GIA rates are of the order of fractions of mm yr−1, generally small – but not negligible – compared to the signals observed at local tide gauges and at GNSS sites in the Po plain and facing the Venetian Lagoon. Our results indicate that, while GIA represents a relatively small component among those responsible for present-day land movements and relative sea-level variations in the northern Adriatic Sea, its contribution needs to be taken into account for a correct interpretation of the observed geodetic variations.
Knowledge about the crustal thickness is one of the key elements in the reconstruction of the regional tectonic history. The Dinaric mountain belt is one of the most enigmatic segments of the ...Alpine‐Mediterranean collision zone, characterized by large variations in crustal thickness and not studied sufficiently. We present a new Moho depth map for the wider Dinarides region which was created using teleseismic earthquake recordings from 87 permanent and temporary seismic stations in the region. Teleseismic data were analyzed using the receiver function method to extract converted P to S waves.
The resulting Moho topography fits well within a structural framework comprising a thicker crust under the Dinarides, which gradually becomes thinner toward the Pannonian and Adriatic domains. The profiles crossing the northwestern Dinarides are marked by a relatively sharp decrease in crustal thickness north of the main thrust front. This transition is followed by significant crustal thinning toward the Pannonian basin. The Mohorovičić discontinuity lies the deepest in the central and southern Dinarides, at depths of over 55 km. Here similarly to the northwestern segment we observe a jump in the crustal thickness when transitioning toward the Internal Dinarides, which hints at possible underthrusting (or subduction) of the Adria plate in this region. Moho depths in the transition zone toward the Pannonian basin and in the Pannonian basin proper vary between 25 and 35 km. In the Adriatic domain, we find crustal thickness ranging from 30 km to more than 45 km around the Central Adriatic islands.
Key Points
New crustal thickness map of the Dinarides and surrounding areas
Thicker crust in the central Adriatic, a deep crustal root in the south Dinarides and a tightly constrained transition from the deep Dinaric to the shallower Pannonian Moho
Jump in the crustal thickness when transitioning toward the Internal Dinarides, which hints at possible underthrusting of the Adria plate in this region
•The mechanism and implications of the BiOS are reported.•BiOS links the deep thermohaline cell to the circulation of the North Ionian Gyre.•The inversions of the North Ionian Gyre affects the ...properties of the Mediterranean Sea.
Over the past four decades, the understanding of Mediterranean oceanography has evolved considerably. From a purely stationary view, there has been a shift to a concept that considers the Mediterranean as a highly dynamic sea in which ocean-typical processes occur on smaller spatial and temporal scales. The recent discovery of the mechanism called BiOS (Adriatic-Ionian Bimodal Oscillating System) has further highlighted the highly variable nature of Mediterranean oceanography and the interconnectedness of its sub-basins.
The BiOS is a mechanism by which the deep thermohaline cell of the eastern Mediterranean, originating in the southern Adriatic, is connected to the upper circulation of the Northern Ionian Gyre via positive feedback, causing a decadal circulation change that leads to a redistribution of salt throughout the Mediterranean.
The effects of this variability are manifold: decadal modulations of the intensity of winter convection in the southern Adriatic, with variations in the volume and thermohaline properties of the dense water produced; variations in preconditioning in the eastern Mediterranean, affecting the salinity of the intermediate Levantine waters; influence on biodiversity in the Adriatic due to the import of Lessepsian organisms or those of western Mediterranean and Atlantic origin; variations of the trophic regime in the Ionian Sea due to the different vertical dynamics of the nutricline during the cyclonic or anticyclonic circulation of the Northern Ionian Gyre; significant contribution to the preconditioning of the northwestern Mediterranean Sea by the salinity variability of the Levantine Intermediate Water.
In this study, the BiOS mechanism, the underlying theory, and the implications for the oceanographic features of the Mediterranean Sea are presented, based on the extensive literature published in the last three decades and some new analyses.
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.
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•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.
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