The accumulation of drift organisms (Arribadas, constituted by benthic microalgae, macroalgae and bryozoans) on Central Beach in Balneário Camboriú (SC) has drawn attention since the early 2000s. However, historical surveys suggest an ancient phenomenon that has been increasing in intensity, promoted by urbanization and the eutrophication of the bay in recent years, leading to changes in the taxonomic composition. Previously, these Arribadas were comprised of two species of benthic microalgae (Amphitetras antediluviana and Biddulphia biddulphiana) and the bryozoan Arbocuspis ramosa. However, since 2019, a substantial increase in biomass has been observed on the beach and the dominance of the macroalgae Bryopsis plumosa strongly suggests an increase in the load of organic matter and nutrients in the bay. Recently (2022) the presence of a new invasive bryozoan species (Amathia alternata) was detected, highlighting the need to continue investigating the Arribadas to monitor the ecological evolution of this process.

Microplastics (MPs) are accessible for organisms with active filter feeding strategies, as are many marine molluscs, which live attached or semi-buried in sediments. In the present study, MPs (from 0.02 to 5 mm) concentration, morphology, and composition were determined in consumed mollusc species of the Catalan coast (NW Mediterranean Sea). Microplastic concentrations, morphologic characteristics and composition were studied according to species, catchment zones and depuration condition. Finally, human intake of MPs through molluscs' consumption was determined. >2300 individuals were analysed, being 1460 MPs extracted and their size, and polymeric composition registered. Big oysters and mussels showed the highest MPs concentration by individual, with levels of 22.8 ± 14.4 and 18.6 ± 23.0 MPs/individual, respectively. Mean annual MPs (≥20 μm) consumption for adult population was estimated in 8103 MPs/year, with a 95th percentile of 19,418 MPs/year. It suggests that the consumption of molluscs is an important route of MPs exposure for the Catalan population.

This study aimed to assess the combined effects of ocean acidification (OA) and pollution to the polychaete Syllis prolifera inhabiting the CO₂ vent system of the Castello Aragonese (Ischia Island, Italy). We investigated the basal activities of antioxidant enzymes in organisms from the acidified site and from an ambient-pH control site in two different periods of the year. Results showed a limited influence of acidified conditions on the functionality of the antioxidant system. We then investigated the responsiveness of individuals living inside the CO₂ vent compared to those from the control to face exposure to acetone and copper. Results highlighted a higher susceptibility of organisms from the vent to acetone and a different response of antioxidant enzymes in individuals from the two sites. Conversely, a higher tolerance to copper was observed in polychaetes from the acidified-site with respect to controls, but any significant oxidative stress was induced at sublethal concentrations.

A novel adsorbent, 3-phenyl-1-(2-pyridyl)thiourea (PPTU) was synthesized and its adsorption capabilities were studied for Cu(II), Cd(II), Ni(II), Pb(II) and Fe(II) cations in the waters such as tap and polluted seawaters. The kinetics, Langmuir and Freundlich isotherms were discussed related to the adsorptions. The adsorption capacities of PPTU were found 9.4; 12.6; 90.9; 57.1 and 30.4 mg g⁻¹ and preconcentration with PPTU including the FAAS step yielded the LOQ values 0.46; 2.65; 1.12; 2.65 and 1.72 ng mL⁻¹ for Cu(II), Cd(II), Ni(II), Pb(II) and Fe(II), respectively. The adsorbent after the elutions and washings could be reused three times in the next adsorptions. The interferences on the adsorptions arising from the major cations of the seawater and the usability of PPTU for interested metals in the seawater were discussed. The proposed method is simple with highly efficient and green preconcentration procedure for trace analysis of the target metal ions.

This study focuses on determination of quantity, shape, size and polymer types of microplastics in Pacific oysters (Crassostrea gigas) cultured in Danang Bay, Vietnam. Visual verification and chemical identification of microplastics was carried out by μFT-IR spectra using Nicolet iN10 MX Infrared Imaging Microscope. The average abundance of microplastic in oysters was 1.88 ± 1.58 particles/g (wet weight) and 18.54 ± 10.08 particles/individual. The prevalent shape of microplastics included three main forms as fragment, fiber and bead corresponding to 73.71; 25.84 and 0.45%, respectively. Additionally, the size of microplastics was a range of 22.4–1318.8 μm, and the most common size was less than 100 μm, accounted for 77.30%. Fifteen polymer types were detected while Nylon was the most abundant polymer type with 50.56%. In this study, microplastics accumulation with their abundance and polymeric structures could be considered as reliable evidence for further studies on assessment of their potential risk to human health.

We examined microplastics (MP) in two commercially important dried fish, Bombay duck (Harpadon nehereus) and ribbon fish (Trichiurus lepturus), collected from two sites on the Bay of Bengal (Cox's Bazar and Kuakata). The number of MP found in dried Bombay duck and ribbon fish from Kuakata was significantly higher (41.33 g⁻¹ and 46.00 g⁻¹, respectively) than the MP present in samples collected from Cox's Bazar (28.54 g⁻¹ and 34.17 g⁻¹, respectively). Fibers were the most common type of MP identified in all samples (41–64%), followed by fragments (22–34%), microbeads (9–16%), films (3–4%), foams (1–4%), and pellets (0–2%). ATR-FTIR analysis revealed three different types of MP polymer - polyethylene (35–45%), polystyrene (20–30%) and polyamide (30–45%) in the dried fish samples. The study confirms the presence of high MP loads in dried fish from the Bay of Bengal, with high potential of trophic transfer of MP to the human body.

Occurrence, distribution, and potential ecological risks of ten organophosphate esters (OPEs) and nine synthetic musks (SMs) were investigated in sediments from the Yangtze River Estuary (YRE) and adjacent East China Sea (ECS). The total concentrations of OPEs in the surface sediments ranged from 0.977 to 19.0 ng/g dry weight (dw) with tris(2-chloro-propyl) phosphate being the dominant component. Total concentrations of SMs ranged from 0.176 to 7.25 ng/g dw, with 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta(g)-2-benzopyran and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene as the dominant SMs. Higher sedimentary concentrations of ΣOPEs and ΣSMs were found in the river mouths of the YRE, inter face of Hangzhou Bay, and mud area of the ECS; the results suggested that terrestrial discharge might be the main source of OPEs and SMs in the studied region. Risk assessment revealed that low ecological risks were posed by OPEs, and limited to low ecological risks were posed by SMs.

The increasing level of marine plastic pollution poses severe threats to the marine ecosystem and biodiversity. Open remote sensing data and advanced machine learning (ML) algorithms could be a cost-effective solution for identifying large plastic patches across the scale. The potential application of such resources in detecting and discriminating marine floating plastics (MFP) are not fully explored. Therefore, the present study attempted to explore the full functionality of open Sentinel satellite data and ML models for detecting and classifying the MFP in Mytilene (Greece), Limassol (Cyprus), Skala Loutron, Greece, Calabria (Italy), and Beirut (Lebanon). Two ML models, i.e. Support Vector Machine (SVM) and Random Forest (RF), were utilized to perform the classification analysis. In-situ plastic location data was collected from the control experiments conducted in Mytilene, Greece (in 2018 and 2019), Skala Loutron, Greece (2021), and Limassol, Cyprus (2018), and the same was considered for training the models. The accuracy and performances of the trained models were further tested on unseen new data collected from Calabria, Italy and Beirut, Lebanon. Both remote sensing bands and spectral indices were used for developing the ML models. A spectral signature profile for marine plastic was created for discriminating the floating plastic from other marine debris. A newly developed index, kernel Normalized Difference Vegetation Index (kNDVI), was incorporated into the modelling to examine its contribution to model performances. Both SVM and RF were performed well in five models and test case combinations. Among the two ML models, the highest performance was measured for the RF. The inclusion of kNDVI was found effective and increased the model performances, reflected by high balanced accuracy measured for model 2 (~89% to ~100% for SVM and ~92% to ~98% for RF). An automated floating plastic detection system was developed and tested in Calabria and Beirut using the best-performed model. The trained model had detected the floating plastic for both sites with ~80%–90%% accuracy. Among the six predictors, the Floating Debris Index (FDI) was the most important variable for detecting marine floating plastic. These findings collectively suggest that high-resolution remote sensing imagery and the automated ML models can be an effective alternative for the cost-effective detection of MFP. Future research will be directed toward collecting quality training data to develop robust automated models and prepare a spectral library for different plastic objects for discriminating plastic from other marine floating debris and advancing the marine plastic pollution research by taking full advantage of open-source data and technologies.

Health and safety of occupations entailing extensive skin contact with cinnabar-enriched sand in beaches of Friuli-Venezia Giulia (FVG) Region (North-eastern Italy) have been questioned for possible skin absorption of mercury (Hg). One hundred mg hair was collected from the occipital scalp of 50 male workers of Grado beach and 121 males from FVG general population. Factors associated with hair Hg content were investigated by multivariable logistic (considering Hg levels >1 vs ≤1 mg/kg) and log-transformed linear regression. The median hair concentration of Hg in male beach workers was 0.70 (IQR = 0.42; 1.34) mg/kg, lower than FVG general population's [1.29 (IQR = 0.87–2.06) mg/kg (p < 0.001)]. In both regression models the hair Hg increased with fish consumption, both among beach workers of Grado and FVG general population. The mean Hg levels in beach workers of Grado fell within an acceptable range, not requiring restrictions of their occupational activities.

This study firstly quantified the responses of seeds of Zostera marina to different planting times (22 September, 5 October, 23 October, 7 November and 20 November in 2015) through a field seed-planting experiment over a two year period. The suitable seed planting time required by the seeds of Z. marina was evaluated. The seedling establishment rate of Z. marina subjected to different planting times ranged from 7% to 55%, with the higher values attained on the treatments of 22 September and 5 October. New plant patches from seed were fully developed and well maintained on the planting time of 22 September, 5 October and 23 October after 2 years following planting. The shoot density under the three treatments ranged from 62 shoots per replicate to 72 shoots per replicate with an average of 67 shoots per replicate in September 2017. According to the propagation assessment and growth analysis, we found that the planting time from mid-September to mid-October may be the optimal time to plant seeds of Z. marina in our experimental site. Our results demonstrate that seed planting time has an important effect on the effectiveness of eelgrass restoration and provide data that could prove helpful in the development of successful eelgrass restoration.