Coastal lagoons are transitional areas between land and sea, particularly vulnerable to human impact. The aim of this work was to compare soft bottom macrozoobenthic communities in the Lagoon of ...Marano and Grado, before (past period: 1993 to 1995) and after the entry into force of the Water Framework Directive-WFD (present period: 2008 to 2021). In the present period higher richness, abundances, and diversity were observed, also considering each water type (euhaline, polihaline and mesohaline) and basin (Marano and Grado) separately. The multivariate analyses also showed differences among periods and water types. According to the AMBI index, most stations were slightly disturbed in all periods and water types, and biocoenotic affinity did not vary significantly. The frequency of echinoderms increased in all water types, whereas the frequency of the polychaete Hedistediversicolor decreased in eu- and polihaline water bodies. These changes can mainly be explained by a general increase in salinity, and therefore probably the result of a marinization process, a decreasing confinement of the lagoon. As the calculation of M-AMBI is derived from AMBI, diversity and richness, this process could lead to a better ecological status sensu WFD, but with the loss of the characteristics and ecological functions of this paralic ecosystem.
•Macrozoobenthos in lagoon before and after WFD application.•Richness, abundances, and diversity increased, stations mostly slightly disturbed (AMBI).•Echinoderms increased, the polychaete H. diversicolor decreased.•Likely result of marinization process.•Better ecological status but loss of ecological functions of paralic ecosystem.
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.
Tetrodotoxins are a potent neurotoxic class of toxins with potentially fatal effects if ingested by humans, and thus, these toxins are a dangerous threat for food safety. Tetrodotoxins are widely ...distributed among various organisms of different taxa, i.e. pufferfish, blue-ringed octopuses and marine gastropods. Lately the presence of these toxins has been reported in mussels (Mytilus sp.). Countries like the United Kingdom, Greece, the Netherlands, and Italy have increasingly notified the detection of tetrodotoxins in these bivalves, which are widely diffused in European shellfish farming. In this context we report, for the first time, the detection of substantial amounts of tetrodotoxins in Mytilus galloprovincialis collected in Italy in a single area of the Northern Adriatic Sea (Marano Lagoon). Tetrodotoxin-positive mussels were identified in samples collected from that geographic area at the end of May in the context of official monitoring programs both in 2017 and 2018. After the positive results were obtained by means of mouse bioassay screening, tetrodotoxins were detected and quantified by HILIC-MS/MS, revealing the bioaccumulation in the mussels of 541 and 216 μg/kg in 2017 and 2018 respectively, the highest amount ever found in mollusks in Europe. The presence of tetrodotoxins at the concentration of 413 μg/kg was further confirmed with Liquid Chromatography coupled to High Resolution Mass Spectrometry in the mussels sampled in 2017.
•Tetrodotoxins are neurotoxic and potentially fatal for humans•Tetrodotoxins were found in shellfishes collected in Northern Adriatic sea•The positive samples were from the same sampling point both in 2017 and 2018•The tetrodotoxin amount for one sample of 2017 was the highest recovered in Europe
An appropriate model for phytoplankton distribution patterns is critical for understanding biogeochemical cycles and trophic interactions in the oceans and seas. Because phytoplankton dynamics in ...coastal waters are more complex due to shallow depth and proximity to land, more accurate models applied to the correct spatial and temporal scales are needed. Our study investigates the role of the atmosphere and hydrosphere in pelagic habitat by modelling phytoplankton assemblages at two Long Term Ecological Research sites in the northern Adriatic Sea using niche-forming environmental variables (wind, temperature, salinity, river discharge, rain, and water column stratification). To study the synchronization between the phytoplankton community and these environmental variables at the two LTER sites, we applied current linear and nonlinear numerical methods for ecological modelling. The aim was to use periodic and/or non-periodic properties of the environmental variables to classify the phytoplankton assemblages at one LTER site (Gulf of Trieste - Slovenia) and then predict them at another LTER site 100 km away (Gulf of Venice - Italy). We found that periodicity played a role in the explanatory and predictive power of the environmental variables and that it was more important than non-periodic events in defining the common structure of the two pelagic habitats. The non-linear classification functions of the neural networks further increased the predictive power of these variables. We observed partial synchronization of communities at the mesoscale and differences between the original and predicted assemblages under similar environmental conditions. We conclude that mesoscale connectivity plays an important role in phytoplankton communities in the northern Adriatic. However, the loss of periodicity of niche-forming variables due to more frequent extreme meteorological and hydrological events could loosen these connections and affect the temporal succession of phytoplankton assemblages.
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•The response of marine phytoplankton to temporal changes in the environment was analysed.•Assemblages were a working model for describing the relationship between the environment and phytoplankton.•Periodicity explained a between 39 and 46 % of the variance in environmental parameters.•We predicted phytoplankton assemblages with more significant IndVal values using environmental periodic components.•The northern Adriatic Sea is a connected mesoscale habitat for the phytoplankton community during autumn and winter.
During the implementation of the INTERREG IT-HR project ECOMOBILITY, whose one of the goals was to estimate the impact of ship emissions on air quality in the port city of Rijeka (Croatia) and Venice ...(Italy), two particular weekly samples were collected in Rijeka, during the first and the thirteen weeks of sampling, i.e. S01 (16.10.-23.10.2018) and S13 (24.04.-30.04.2019.), respectively. Both samples have similarities regarding species characteristic for desert dust contribution, but HYSPLIT analyses excluded Saharan desert to be the source of the S01 sample. Unlike Saharan dust, this sample had a high contribution of fine and ultrafine particles (>50 % and 9.8 %, respectively), as well as secondary inorganic (sulfates, ammonium) and organic (water soluble organic compounds - WSOC) aerosols. Detailed synoptic situation and HYSPLIT backward trajectories pointed out the Syrian Desert as the source of this collected sample. The same source was proved by MERRA-2 reanalysis of the desert dust emission. Although the Saharan dust episodes, mostly in precipitation, are well known in the Northern Adriatic area, this is the first time to indicate Syrian Desert as a source of airborne particulates. This assumption was confirmed with chemical species characteristic for the Syrian Desert, i.e. higher content of potassium from K- feldspar and phosphates.
NOAA HYSPLIT MODEL, GDAS Meteorological data. Display omitted
•Desert dust episodes•Chemical characterization of particulate fractions•Meteorological analysis of dust sources (HYSPLIT)•The MERRA-2 reanalysis•Identification of Syrian desert as another desert source
Dynamics of the physical and biogeochemical properties in a temperate coastal area in the north-western Adriatic Sea were analyzed. Multi-year (1997–2019) continuous observations allowed assessing ...their trends at two sites directly influenced by the discharges of two minor rivers as well as by human activities and climate change. Statistical models were applied to investigate the temporal variability and trends of seawater temperature, salinity, chlorophyll a, nutrients, river discharges and precipitations. The analysis highlighted a role for the minor river inputs and for ecological processes on interannual and seasonal biogeochemical dynamics. We found a significant trend toward more oligotrophic conditions; in particular, chlorophyll a exhibited a long-term decline (−1.38% year−1 and - 1.5% year−1 at the two Foglia and Metauro river transects, respectively) that was largely determined by low phosphate and nitrate seawater concentrations as a result of a significant reduction in the phosphate and nitrate loadings of the two minor rivers (respectively mean values of −4.65% year−1 and -2.65% year−1). In contrast, salinity showed a long-term decrease of −0.24% year−1 and -0.19% year−1 at Foglia and Metauro, respectively, corresponding to a significant increase of the freshwater discharges of the two minor rivers (+1.86% and +1.57% year−1 at Foglia and Metauro, respectively) possibly due to precipitations. Data analysis highlighted the conditions of temperate coastal areas affected by freshwater discharges. Nutrient load management and climate conditions such as precipitation regimes appear to be the main factors driving physical and biogeochemical dynamics in the north-western Adriatic Sea.
•Data series allowed assessing changing biogeochemical coastal dynamics.•Role of the minor river inputs on interannual and seasonal biogeochemical dynamics.•Oligotrophic trends in NW Adriatic coastal waters by reduced P and N riverine inputs.•Nutrient load and climate changes as drivers of biogeochemical dynamics in Adriatic Sea.
Organotin compounds (OTC), tri-, di- and monobutyl tin, were determined in the tissues of marbled electric ray (Torpedo marmorata) in the Adriatic Sea. Marbled electric ray specimens were provided by ...local fishermen from three localities in the northern Adriatic: area close to the shipyard in Seča, the natural protected area Strunjan Nature Reserve and along the west Istrian coast. To assess the concentration of OTC in the environment, sediment samples were also analysed. After an adequate extraction of OTC from both matrices, their concentrations were determined by GC-ICP-MS.
The results indicate that the accumulation of TBT (tributyltin) and DBT (dibutyltin) in the marbled electric ray is related to the possible pollution sources, since their total concentrations were significantly higher (p < 0.001) in the area close to the shipyard (up to 69 μg Sn kg−1, w.w.) in comparison to the other two areas less affected by direct pollution (up to 7 μg Sn kg−1, w.w.). TBT concentrations ranged from 2 to 42 μg Sn kg−1, w.w., DBT concentrations were in the range from 2 to 22 μg Sn kg−1, w.w., and MBT concentrations were mostly below the detection limit with the highest up to 4 μg Sn kg−1, w.w. The proportion of the three determined congener concentrations in sediment samples indicate a temporally older pollution with these compounds, with prevailing DBT and MBT concentrations up to 30 μg Sn kg−1, w.w., and much lower TBT concentrations up to 7 μg Sn kg−1, w.w.
According to our results, marbled electric ray could be considered as an ideal bioindicator of environmental pollution due to its ecological characteristics.
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•The first study on the OTC content of the marbled electric ray (Torpedo marmorata)•The accumulation of OTC is related to the possible sources of pollution.•Accumulation of OTC in the selected elasmobranch species is still significant.•Marbled electric ray could be an ideal bioindicator for environmental pollution.
Weathering indices are widely used in soil science and some other environmental disciplines for a variety of purposes (e. g. for soil classification, in soil formation studies, or in wider ...palaeoclimatic research). Two main categories of weathering indices have been developed: geochemical and mineralogical. In both cases, an approach is developed that takes into account the compositional nature of the geochemical data. To date, however, the most commonly used weathering indices are geochemical indices that do not consider the geochemical data as compositional. Although the compositional approach minimises possible statistical errors, the weathering indices developed in both approaches, i.e., compositional and classical, axiomatically assume two things that are inaccurate in some cases. First, that soil composition is invariant with respect to the preferential translocation of clay-sized particles, i.e. lessivage, and second, that the selective sorting of minerals during transport does not affect the values of weathering indices. As a result, in some cases bulk analyses of mineralogical and geochemical content are an unreliable tool for determining weathering rates of soil. To overcome these difficulties, this study proposes a new weathering index (Wp-min) based on the orthonormal log ratio (olr) transformation of quantitative mineral data derived from silt- to sand-sized allochthonous mineral assemblages. The size fraction used ensures that only the parent mineral assemblages, which are not prone to translocation, are analysed. In this paper, olr transformation is done using the concept of balances. This enabled the construction of variables, which essentially are various mineral log ratios, with the desired properties, i.e. transport invariance and sensitivity to selective dissolution. In this way, undesirable effects, i.e. selective sorting and lessivage, which ultimately affect bulk analyses, are avoided, allowing a more accurate estimation of weathering in the soil profiles studied. The new index was validated by comparison with the geochemical W index, which was modified by consulting the standardized variation matrix prior to element selection. Ultimately, compared to the geochemical index, the new index was better able to characterise weathering in soils where intense lessivage was detected. The study was conducted on terra rossa soils, which have common source, mostly of aeolian origin.
•The process of lessivage compromises conclusions about weathering•Modification of an existing geochemical index•Weathering rate derived from silt-sand sized fraction of parent minerals•Construction of a new weathering index
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.
•Model for coherent provenance analysis of soils based on heavy mineral assamblages.•Weathering pattern of heavy minerals suggests the parent material of terra rossa.•Recurrent supply of ...siliciclastic material from emerged shelf is crucial for terra rossa formation.
Coherent provenance studies of soils that take into account data processing and the limitations arising from the physiochemical properties of the source material are scarce. In this study, the provenance of four terra rossa soils on the Istrian peninsula and four terra rossa soils on the island of Susak is investigated based on the heavy mineral assemblages of the soils and their potential sources. The heavy mineral data are treated as compositional data, which means that the information is stored in the ratio between the components and not in absolute values. The provenance of the allochthonous soil components showed that they originated from the now submerged alluvial plain i.e., emerged Adriatic shelf, mainly fed by alpine material during low sea levels. In the case of Savudrija loess and red paleosol and partly Koreniki sections, the allochthonous material originated from the local Eocene flysch, also windblown from the emerged shelf. The degree of mineral weathering, which correlates with the Fed/Fet and the total portion of heavy minerals, shows that this allochthonous component is a parent material of the terra rossa soils, not an impurity. Thus, the main role of the carbonate rocks with which the terra rossa soils are associated is to maintain a specific and favorable conditions for their formation. The origin of the parent material is associated with sea level oscillations, i.e., in times of low sea level the material was windblown from the emerged shelf, onto the land, this recurrent process can probably be traced back to the Oligocene. During periods of high sea level, i.e., warmer periods, terra rossa formed. Thus, the formation of terra rossa soils in the northern Adriatic is a recurrent process that may have begun at least since the Miocene. Consequently, abundance of terra rossa on the eastern Adriatic coast is due to a large emerged shelf area that supplied the carbonate platform with siliciclastic material during low sea levels.
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