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.

Eutrophication represents one of the most impacting threats for the ecological status and related ecosystem services of transitional waters; hence, its assessment plays a key role in the management of these ecosystems. A new multi-index method for eutrophication assessment, based on the ecological index MaQI (Macrophyte Quality Index), the trophic index TWQI (Transitional Water Quality Index), and physicochemical quality elements (sensu Dir. 2000/60/EC), was developed including both driver and impact indicators. The study presents a large-scale implementation of the method, which included more than 100 Italian lagoon sites, covering a wide variability of lagoon typologies and conditions. Overall, 35% of sites resulted in eutrophic status, 45% in mesotrophic, and 25% in oligotrophic status.

Mercury (Hg) is a global pollutant, being highly persistent in the atmosphere, in particular gaseous elemental mercury (GEM), which can easily be emitted and then transported over long distances. In the Gulf of Trieste (northern Adriatic Sea, Italy), contamination by Hg is well characterised but little is known regarding the concentrations, sources and fate of GEM in the atmosphere. In this work, discrete measurements of GEM were recorded from several sites at different times of the year. The database is consistent with temporal night-day variations monitored using a continuous real-time device. The meteorological conditions were collected as ancillary parameters. GEM levels varied from <LOD (2.0 ng m⁻³) to 48.5 ng m⁻³ (mean 2.7 ng m⁻³), with no significant differences found among sites. A clear daily pattern emerged, with maximum values reached just after sunset. Air temperature, relative humidity, wind speed and direction were identified as the main micrometeorological factors influencing both the spatial and temporal variation of GEM. Our results show that average atmospheric GEM values are higher than the natural background of the Northern Hemisphere and will be useful in future selection regarding the most suitable sites to monitor atmospheric Hg depositions and fluxes from soil and water.