Mercury (Hg) is a global pollutant capable of bioaccumulates/biomagnifies along the trophic chain and posing concerns for organisms and humans. The historical mining in Idrija (NW Slovenia) and the ...more recent activity of a chlor-alkali plant (CAP) sited in Torviscosa (NE Italy) causes diffuse Hg contamination in the Marano and Grado Lagoon (MGL, northern Adriatic Sea, Italy). Despite the importance of fishing and aquaculture for local inhabitants, knowledge of the Hg content of MGL fish is still scarce and fragmentary. This paper reports the results obtained from the collection of sediments, water, and biota during the implementation of the WFD/2000/60/CE. The solid phase is characterised by high Hg concentrations (up to 7.4 mg kg−1) with a net positive gradient moving eastward, but chemical speciation suggests the prevalence of cinnabar (not mobile) species. The scarce mobility of Hg is attested to by the low concentrations found in surface waters. Hg in fish often exceeds the limit set for commercialization (0.5 mg kg−1 ww), especially in the Grado basin, but its content is variable depending on the size and habits of species. Although there was a significant linear relationship between THg content in sediment and tissues of Chelon auratus, the values of the biota sediment accumulation factor (BSAF), which were always less than one, suggest that the Hg bioavailable for transfer from sediment to biota is low. Additionally, the Target Hazard Quotient (THQ) calculated on C. auratus’s daily consumption showed that adverse effects on human health are out of the question at least for the Marano basin.
•We report spatial distribution of PAHs.•PAHs ranged from <lod to 1056ngg−1.•Pyrolitic sources are predominant.•Environmental quality standards application suggests a negligible biological risk.
The ...Marano and Grado Lagoon is one of the best conserved transitional environment in the whole Mediterranean area. On the other hand, it suffers from industrial, agricultural and fisheries activities, which could have an important impact on its environmental quality. With the application of the WFD, the sediment chemical status was investigated. In this work, 16 polycyclic aromatic hydrocarbons included by the US EPA within the priority pollutants were considered. PAHs values ranged from non-detectable to 1056ngg−1 showing the highest contamination close to the Aussa-Corno River mouth, which received the industrial inputs. The contamination level was comparable to that observed in low contaminated sites of the Mediterranean region, and lower than the adjacent Gulf of Trieste. The ratios of selected PAHs congeners pointed out the prevalence of pyrolitic sources. Moreover, the application of the ERL/ERM displayed an environment, which should not have a potential biological impact.
The Marano and Grado Lagoon (Adriatic Sea, Italy) is an important transitional environment that furnishes numerous ecosystem services and is under protection as Site of Community Importance. It ...suffers from an excess of nutrients, especially nitrate (NO3−), and has been designated as a nitrate vulnerable zone. In this work, sixteen water bodies were seasonally monitored for physicochemical parameters and nutrients, to elucidate the trophic state of the lagoon and to check the occurrence of significant temporal trends in a time series from 2011 to 2021. Steep gradients of spatial and seasonal distribution were observed for all parameters with elevated concentration of N-NO3− (up to 360 µM) in the western sector. The whole lagoon was in phosphorous limitation (P-PO43− mean ± s.d. = 0.15 ± 0.22 µM) with a mean Redfield ratio of 1130. The concentration of nutrients was significantly correlated with the degree of both freshwater inputs and precipitation. The calculation of trophic indices shows that the lagoon is in an oligotrophic to hypertrophic condition (i.e., TRIX 1.9–6.8). The analysis of the temporal series showed that despite some significant trends, the time span considered is too short to detect significant changes in the trophic state of this dynamic environment.
In the northern Adriatic Sea, rocky outcrops called “trezze” or “tegnúe” are known as biodiversity hotspots. A total of 45 rocky outcrops were studied by using non-destructive photographic sampling ...during SCUBA diving. Ten invertebrate phyla with 196 taxa were recorded, 86% of which were determined at species level. Among them, 65% of the taxa were sessile, primarily represented by the phyla Porifera and Chordata. The aims of the study were: to characterize the species richness and composition of epifaunal invertebrates living on rocky outcrops; to test the efficiency of using the outcrop area as a predictor of epifauna richness, using the Arrhenius Species-Area Relationship (SAR) model; and to compare the expected richness resulting from the SAR model with the richness observed from the analysis of random photo-squares. Our results show that the SAR model describes the relationship between epibenthic species richness and outcrop size well and may have important practical applications for biodiversity estimations and nature conservation implications. It provides a useful tool, also in terms of economy and speed, to estimate the species richness of the benthic epifauna of the numerous outcrops that remain unsurveyed, based on their size.
Mercury (Hg) and its bioaccumulation are important in evaluating the health risk through fish consumption. In the Marano and Grado Lagoon a historical contamination originating from both mining and ...industrial sources is present.
In this study the Hg levels in the grass goby and the protective effect of selenium (Se) were determined as a function of size, sex, sampling sites and season.
Mercury often exceeded the limit for commercialisation, whereas Se was mostly constant being homeostatically regulated.
The mean Se/Hg molar ratio showed about 40% of data >1.0 and the HBVSe index was on average equal to 0.0. Thus, grass goby of this area is not a Se source food indicated for pregnant and/or breastfeeding women, but its occasional consumption would appear to have no contraindications if integrated with other Se rich foods: the ingestion of about 10 fish fillets per week can be safely consumed by adults.
•The Marano and Grado Lagoon is historically contaminated with mercury;•Zosterisessor ophiocephalus is an active bioaccumulator of Hg, sometimes exceeding the limit for commercialisation;•Bioaccumulation is enhanced in female specimens during the reproductive season;•The Se incomplete protection against Hg must be supported with an appropriate supply in the diet;•A weekly ingestion of about 150 g of fillet is safe for adults.
Dissolved oxygen (DO) is a key element for the survival of marine organisms and is a supporting element in the current Water Framework Directive (WFD). DO deficiency is a common event that occurs in ...coastal environments such as estuaries and lagoons, but a long-term DO database that helps detect daily and seasonal oscillations is difficult to obtain with commonly used sampling and analytical procedures. In this work, a network of multi-parametric probes was deployed in the Marano and Grado Lagoon (northern Adriatic Sea, Italy) in order to obtain a dataset from the continuous monitoring of DO and complementary parameters. DO showed a high degree of variability both in terms of spatial and seasonal distribution and was dependent on solar radiation and water temperature. During the summer and in areas characterised by scarce water renewal, DO was below the threshold set as the minimum requirement for aquatic life, thus some water bodies (WBs) were classified as moderate sensu WFD. The inputs of freshwater discharge from inland and marine waters during tides are, however, able to well oxygenate most of the lagoon. These results will be useful in supporting the management and protection of this vulnerable environment.
Since August 2015, an increasing number of Blue Crabs, Callinectes sapidus Rathbun, 1896, have been reported in the Marano and Grado Lagoon, Gulf of Trieste, in the northern Adriatic Sea. This ...species is not a new introduction and in fact the first record of C. sapidus in Italy and the entire Adriatic Sea dates back to 1949 in the Grado Lagoon. Interestingly, no other records of C. sapidus have been reported since the first record. Here, we note the re-appearance of C. sapidus in the Gulf of Trieste.
Dvajsetega junija 2023 so ribici v trislojno mrezo ujeli primerek kostanjevke Brama brama (Bonnaterre, 1788) (Bramidae) na 5 m giobine v Trzaskem zalivu. B. brama je pelaska neriticna oceanodromna ...vrsta, ki se pojavlja povsod v zmernih in toplih morjih v globinskem razponu med 0 in 1000 m giobine, obcasno pa se pribliza obali. V vzhodnem Sredozemskem morju in jadranskem morju jo smatrajo za redko vrsto. Pricujoci zapis je najnovejsi v Trzaskem zalivu, so pa znani zgodovinski zapisi, katerih primerki so shranjeni V Trzaskem prirodoslovnem muzeju.
Transitional environments have great ecological value and high productivity, and many species can benefit from their sheltered conditions and food resources. In this study, we performed for the first ...time a fish-targeted eDNA metabarcoding of the 12S rRNA gene at 16 sites broadly covering the different water bodies of the Marano and Grado Lagoon (northern Adriatic Sea) in two seasons. The eDNA was collected at the same time as the beach seine net, allowing a direct comparison of the two approaches.
With eDNA we detected 34 species, covering all the functional guilds occurring in the lagoon. Species of regional interest, that uses the area as a nursery and feeding ground, and diadromous species, highlighting the ecological connectivity between freshwater and marine habitats, were found. While some species were constantly present (e.g. Atherina boyeri, Sparus aurata), others (Squalius cephalus, Platichthys flesus) were influenced by salinity (higher in Grado and lower in Marano), which was confirmed as the main ecological driver in this environment. The comparison with traditional methods, which identified 18 species (11 of which were detected with both approaches), showed that eDNA is very sensitive in detecting most of the biodiversity in the lagoon with a limited sampling effort. Few relevant species (Chelon saliens, Knipowitschia panizzae) lacked reference sequences, which need to be implemented in the databases. Our study represents a significant advance in the understanding of lagoon fish biodiversity and ecological dynamics and contributes to the improvement of management strategies in these ecologically sensitive habitats.
•eDNA detected a great richness of fish species, across different functional groups•The molecular approach (eDNA) was more sensitive than the traditional one (seine net)•Reference databases still lack sequences of relevant lagoon fish species
The long discussion on the identity of the large Eunice species from the Adriatic and Mediterranean Seas is a result of the broader discussion on the identity and synonymy of Eunice roussaei and ...Eunice aphroditois. Here we show that the species occurring in the Adriatic Sea is Eunice roussaei and how this species can be differentiated from Eunice aphroditois; we also characterize the Mediterranean Eunice roussaei.
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