Search Results (186)

This study investigated the presence and distribution of macrolitter along four beach sites on the Ferrara coast, North-eastern Italy. At each site, monitoring campaigns were conducted from summer 2023 to summer 2024 to assess seasonal and cross-shore fluctuations of litter items and their relations with local geomorphological features. Following the Marine Strategy Framework Directive, 5627 litter items were collected, with an average density of 0.61 ± 0.23 items/m². Plastic was the dominant material, representing 94% of the total. The Clean Coast Index (CCI) was applied to evaluate beach cleanliness, seasonal patterns, and cross-shore litter distribution. Although the sites were generally classified as “Clean”, CCI values revealed a progressive decline in cleanliness from summer to spring. Litter was especially accumulated in the upper backshore and at the dune foot. All macrolitter items were classified by material, typology, and usage category to identify potential sources of release, following the Joint List of Litter Categories for Marine Macrolitter Monitoring. The “Top 10” of the most collected items was compiled per each site, season, and geomorphological zone. The results underscore the relevance of high-resolution monitoring programs to support the development of targeted management strategies for effective beach litter mitigation. Full article

The Atlantic blue crab (Callinectes sapidus) has rapidly expanded across the Mediterranean, raising concerns over its ecological and economic impacts. This study examines the morphometric characteristics and environmental influences on C. sapidus populations in the Palud-Palù swamp (western Istrian coast) from 2022 to 2024. A total of 203 specimens were analyzed for carapace width, length, depth, and body mass, alongside monthly measurements of temperature, salinity, oxygen saturation, and pH. Statistical analyses (t-tests, ANOVA, PCA, and RDA) revealed pronounced sexual dimorphism, with males consistently larger than females. Interannual differences in size distribution showed larger individuals in 2022, followed by a decline in 2023 and 2024, likely due to environmental stressors (e.g., salinity, temperature, hypoxia) and increased anthropogenic pressures (e.g., trapping and illegal harvesting). RDA identified temperature, oxygen saturation, and pH as key abiotic drivers of morphometric variation. These findings suggest that while C. sapidus demonstrates physiological plasticity, enabling its persistence in estuarine environments, its growth and invasive potential may be constrained under extreme or suboptimal local conditions. This study highlights the importance of long-term monitoring and integrated management to mitigate ecological disruption in sensitive coastal ecosystems. Full article

Accurately hindcasting waves in semi-enclosed, fetch-limited basins remains challenging for reanalysis models, which tend to underestimate storm peaks near the coast. We developed interpretable ML models for Rijeka Bay (northern Adriatic) using only wind observations from two land-based wind stations to predict buoy H_m0 measurements spanning 2009–2011 (testing) and 2019–2021 (training and validation). The tested tree-based models included Random Forest, XGBoost, and Explainable Boosting Machine. This study introduces a novel approach in the literature by employing weighted schemes and feature engineering to enhance the predictive performance of interpretable, low-complexity machine learning models in hindcasting waves. Representing wind direction as sine–cosine components generally reduced RMSE and BIAS relative to traditional speed–direction inputs, while an exponential sample weight scheme that emphasized storm waves halved extreme H_m0 underprediction without inflating overall RMSE. The best-performing model, a Random Forest model, achieved an RMSE of 0.096 m and a correlation of 0.855 on the unseen test set—30% lower overall RMSE and 50% lower extreme wave RMSE than the MEDSEA and COEXMED hindcasts. Additionally, the underprediction was reduced by 90% compared to these reanalysis models. The method offers a computationally lightweight, transferable supplement to numerical wave guidance for coastal engineering and harbor operations. Full article

Plastic pollution in marine environments is a globally recognized concern that poses ecological and economic threats. While 80% of plastic originates from land, 20% comes from sea-based sources like shipping and fishing. Comprehensive assessments of fishing-related plastics are limited but crucial for mitigation. This study analyzed the distribution and temporal evolution of three fishing-related items (EPS fish boxes, fragments, and buoys) along the Bocassette spit in the northern Adriatic Sea, a region with high fishing and aquaculture activity. UAV monitoring (November 2019, June/October 2020) and structured interviews with Po Delta fishermen were conducted. The collected debris was mainly EPS, with boxes (54.8%) and fragments (39.6%). Fishermen showed strong awareness of degradation, identifying plastic as the primary litter type and reporting gear loss. Litter concentrated in active dunes and the southern sector indicates human and riverine influence. Persistent items (61%) at higher elevations suggest longer residence times. Mapped EPS boxes could generate billions of micro-particles (e.g., ~10¹³). The results reveal a complex interaction between natural processes and human activities in litter distribution. This highlights the need for integrated management strategies, like improved waste management, targeted cleanup, and community involvement, to reduce long-term impacts on vulnerable coastal ecosystems. Full article

Sea level rise (SLR) and increased urbanisation of coastal areas have exacerbated coastal flood threats, making them even more severe in important cultural sites. In this context, the role of hard coastal defences such as promenades and embankments needs to be carefully assessed. Here, a thorough investigation is conducted in Grado, one of the most significant coastal and historical towns in the Friuli Venezia Giulia region of Italy. Grado is located on a barrier island of the homonymous lagoon, the northernmost of the Adriatic Sea, and is prone to flooding from both the sea and the back lagoon. The mean and maximum sea levels from the historical dataset of Venice (1950–2023) were analysed using the Gumbel-type distribution, allowing for the identification of annual extremes based on their respective return periods (RPs). Grado and Trieste sea level datasets (1991–2023) were used to calibrate the statistics of the extremes and to calculate the local component (subsidence) of relative SLR. The research examined the occurrence of annual exceedance of the minimum threshold water level of 110 cm, indicating Grado’s initial notable marine ingression. The study includes a detailed analysis of flood impacts on the urban fabric, categorised into sectors based on the promenade elevation on the lagoon side, the most vulnerable to flooding. Inundated areas were obtained using a high-resolution digital terrain model through a GIS-based technique, assessing both the magnitude and exposure of the urban environment to flood risk due to storm surges, also considering relative SLR projections for 2050 and 2100. Currently, approximately 42% of Grado’s inhabited area is inundated with a sea level threshold value of 151 cm, which occurs during surge episodes with a 30-year RP. By 2100, with an optimistic forecast (SSP1-2.6) of local SLR of around +53 cm, the same threshold will be met with a surge of ca. 100 cm, which occurs once a year. Thus, extreme levels linked with more catastrophic events with current secular RPs will be achieved with a multi-year frequency, inundating more than 60% of the urbanized area. Grado, like Venice, exemplifies trends that may impact other coastal regions and historically significant towns of national importance. As a result, the generated simulations, as well as detailed analyses of urban sectors where coastal flooding may occur, are critical for medium- to long-term urban planning aimed at adopting proper adaptation measures. Full article

We studied the feeding habits of the common eagle ray (Myliobatis aquila) in the shallow northern Adriatic Sea. Altogether we analysed the contents of 122 stomachs of specimens caught as by-catch in the Gulf of Trieste and along the west Istrian coast. Shelled molluscs (N% = 75.17), mainly bivalves and gastropods, were the most prominent prey categories, while crustaceans, sipunculids, echinoderms and polychaets (N% < 10) represented considerably smaller numbers. With increasing size (and age) the eagle rays tend to become more experienced in preying molluscs and specialized to this prey category. The obtained results are in general in agreement with the limited existing reports on the diet of the common eagle ray in the Mediterranean Sea and adjacent areas. Full article

The blue crab (Callinectes sapidus) is an invasive alien species in the Mediterranean Sea, posing threats to biodiversity, fisheries, and aquaculture. Climate change has worsened these challenges, influencing the distribution of bacterial species, including Shewanella species, which are sensitive to changes in temperature and salinity. In this study, 300 blue crabs were sampled between June and October 2024 from the Sacca di Goro (Northern Adriatic Sea, Italy) to investigate the prevalence of Shewanella species in their haemolymph. The prevalence was found to be 7% (21/300), with species such as S. mesophila, S. algae, S. cowelliana, and S. baltica identified, particularly in the months of September and October. Molecular techniques, including MALDI-TOF MS and rpoB gene amplification, were used to identify isolates. Antibiotic susceptibility testing (AST) revealed a trend of resistance to beta-lactam antibiotics. A network analysis was also conducted to examine the global trends of Shewanella research in relation to humans, animals, and the marine environment. While proper cooking eliminates the risk to consumers, handling without personal protective equipment can increase exposure, particularly for vulnerable individuals such as those who are elderly or immunocompromised. Mild symptoms are observed in children. Further studies, particularly with a One Health approach, are crucial to better understand the transmission dynamics and evolving antibiotic resistance of Shewanella species. Full article

Marine fouling communities, characterized by a high abundance of suspension feeders, play a crucial role in regulating ecosystem services, particularly in improving seawater quality. While not typically prioritized in conservation due to their prevalence in degraded or artificial habitats, fouling communities are important for their ecological functions under increasing urbanization and climate change. Bryozoans are an important component of these communities, although their filtering activity is less understood compared to some other groups, such as bivalves and ascidians. In this paper, we aimed to investigate the filtration activity of two widespread fouling bryozoan species, namely Schizoporella errata and Bugula neritina in the northern Adriatic (Slovenia). We measured the clearance rates (CR) of both the species when fed with microalgae to assess their filtration capacity and determine the most suitable units for quantifying the biofiltration. B. neritina exhibited a higher average CR than S. errata. The maximum CR was 32 mL/(h·cm²) for the S. errata and 52 mL/(h·cm²) for the B. neritina. Due to the morphological and growth differences between the species, the surface area was determined to be the most appropriate unit for expressing the CR. We also examined the CR of the S. errata exposed to fluorescent microplastic beads and identified active feeding areas within the colonies. Feeding zooids in S. errata were concentrated at the terminal growth margins and elevated areas of the frontal budding, as indicated by a higher fluorescence and microsphere density. These results contribute to the existing knowledge on fouling bryozoans in coastal habitats and provide further insights into their potential role as biofilters and contributors to ecosystem functioning. Full article

Marine litter threatens ocean ecosystems, and nautical tourism, as a source of litter, contributes significantly. This paper presents a qualitative and quantitative study of seafloor litter in the Bay of Selehovica in the northern Adriatic Sea. The bay is accessible only by sea and is attractive to nautical tourism vessels. The survey was conducted using a remotely operated vehicle across 22,100 m² of seafloor, before and after the tourist season (summer) in 2024. The analysis shows a 25.90% increase in litter items after one season. The predominant litter category is plastic, followed by glass, metal, rubber, and textiles. The abundance of marine litter increased from 1.3 to 1.7 items per 100 m² in the post-season, reflecting a measurable rise in litter density. Due to non-normal data distribution (Shapiro–Wilk test, p < 0.001), the Wilcoxon Signed-Rank Test was used, revealing a statistically significant increase in marine litter (W = 0, p < 0.001) with a large effect size (Cohen’s d = 0.89). A strong positive correlation between the pre- and post-season values was observed (Spearman’s r = 0.96, p < 0.001), suggesting that areas with higher initial litter levels tend to accumulate more over time. The results point to the necessity of targeted management strategies to reduce the pressure of nautical tourism on marine ecosystems and to protect the marine environment. Full article

The shells of dead Pinna nobilis individuals are important habitats in sedimentary coastal ecosystems, yet their ecological role is poorly understood. This study investigated macrofaunal communities associated with 80 P. nobilis shells from Soline Bay and Valovine Bay, northern Adriatic, analyzing variations in species abundance and biodiversity between shell orientations (vertical and horizontal) and across seasons. Shell dimensions were recorded, with larger shells and higher faunal abundance observed in Soline Bay compared to Valovine Bay. A total of 2225 individuals representing 183 species across 19 taxonomic groups were identified, with Malacostraca, Bivalvia, and Polychaeta being the most abundant. Vertically positioned shells hosted significantly more organisms than horizontally positioned ones, likely due to greater available surface area for settlement. Seasonal changes influenced organism abundance, with peaks in winter for Valovine Bay and spring for Soline Bay, correlating with environmental factors such as eutrophication. The most frequent species associated with the shells of dead individuals were the polychaete Sabella spallanzanii and the bivalve Rocellaria dubia, which can impact shell degradation. Despite their temporary nature, the shells of dead P. nobilis provide vital refuge and enhance biodiversity. The findings underscore the ecological importance of P. nobilis shells as biodiversity hotspots and highlight the need for their conservation and further study. Full article

A series (n = 22) of glasses from the site Kapucinski vrt (garden of the Capuchin monastery, 5th–17th c. CE) in Koper (Capodistria), a port town in the northern Adriatic, was measured using a combined PIXE and PIGE method. Koper has been continuously populated since the late Roman period, with a rich medieval history, thus offering an opportunity to study Early Medieval glass. Stemmed goblet fragments, in the original publication dated between the 6th–9th centuries CE, and several other vessel types (beakers and flasks or bottles and lamps) were selected for analysis. The measurements were expected to show the trends in glass production and consumption from Late Antiquity until the Middle Ages, notably the transition between natron to plant ash glass and the supply of fresh glass. Among the set of 22 glass vessel fragments, both natron and plant ash glass were identified. For finer classification, we relied on a newly developed method of Euclidean distances with respect to major concentrations. Natron glass of the types Foy 2.1 (9 examples), Magby (2 examples), and Levantine I (Apollonia; 2 examples) was found. Two glasses remain undetermined but testify to an Egyptian origin. Most natron glasses show signs of recycling. Among the three unrecycled glasses (about 20% of the whole set), there are two examples of Levantine glass and a Magby glass lamp; this may indicate a modest supply of fresh glass during the period. Plant ash glass may be attributed to the Early or High Middle Ages, exploiting the purified alkalis of the Levantine coasts (known as alume catino in later Venetian glassmaking), and the admixture of impurities in the siliceous sands suggests the circulation and consumption of glass that was produced and traded in the eastern Mediterranean since the 10th century CE. Full article

Polychaetes are important marine invertebrates that contribute to sediment bioturbation, nutrient recycling, and food web dynamics. This study examines the diversity and structure of the polychaete assemblages associated with the red algae Corallina officinalis in areas with different levels of anthropogenic pressures of the Northeastern Adriatic Sea. Sampling was performed in the intertidal zones. Altogether, 54 species from 13 families were found, with Syllidae being the most abundant. Polychaete richness, relative abundance and diversity at sampling locations with and without anthropogenic pressures showed no significant difference. Multivariate analyses revealed significant differences in species composition between sites under anthropogenic pressures and those without, with key species such as Sphaerosyllis pirifera, Syllis rosea, Syllis prolifera, Syllis gerundensis, and Platynereis dumerilii playing significant roles. Syllis rosea was the most abundant in locations without anthropogenic pressures, while S. pirifera was the most abundant in locations under anthropogenic pressures. These results suggest that while polychaete communities are resilient, anthropogenic pressures are causing shifts in species composition. This pattern is consistent with the results of related studies, indicating a broader ecological trend. The shifts observed here should raise concern among conservation ecologists, underscoring the importance of long-term monitoring to understand and mitigate the impacts of human activities on coastal ecosystems. Full article

Coralligenous bioconstructions are priority habitats crucial for the protection of Mediterranean marine biodiversity. Among these bioconstructions, the mesophotic biogenic reefs of the northern Adriatic are of particular concern due to their ecological relevance and the high levels of human pressure in the region. Thus, effective monitoring strategies are vital for the conservation and management of these fragile environments. In this study, we investigated the multivariate spatial and temporal patterns of sessile macrobenthos on biogenic reefs within two areas of a Natura 2000 site in the northern Adriatic over a four-year period. We also classified the ecological status of reefs based on the NAMBER index, specifically tailored for these peculiar bioconstructions. Our findings revealed that temporal trajectories of assemblages significantly differed between the two investigated areas, mostly due to larger fluctuations in algal turf abundance in the area closest to the coast, which is putatively more exposed to human impacts. In this area, the index identified a “Moderate” status during the period of peaking turf abundance, while the reef status consistently remained “Good” in other periods and in the area located further from the coast. This highlights the index sensitivity in reflecting actual changes in assemblages potentially associated with reef degradation. Full article

The present study aimed at identifying the transformations that occurred since the 1600s in a low-lying territory located east of the Venice Lagoon. The environmental modifications were examined in a GIS environment through the interpretation of multidisciplinary data. The analysis of historical maps realized from 1641 to 1943, as well as aerial photographs and satellite images taken in the last few decades, was fundamental to reconstruct the evolution of the study area mainly in relation to anthropogenic processes. Over the past few centuries, various attempts of land reclamation partially or totally failed. However, even if an overall general decrease in both the total pond surface area and the marsh extension has been observed since the 19th century, the territory appeared entirely dry back only in the 1940s owing to the efficacy of the main most recent works. Full article

In the Caleri lagoon, a coastal lagoon in the Po River Delta, Northern Adriatic, the transplant of the dwarf eelgrass Zostera noltei was used as a nature-based solution to attempt the ecological restoration of a previously depleted lagoon area. A total of 135 15-cm-diameter sods were transplanted, with the donor site at the Venice lagoon. Using unmanned aerial vehicles (UAVs), eelgrass transplants were mapped and monitored with great precision. After two years, the area covered by eelgrass increased from the initial 2.5 m² to 60 m². Changes in the community structure and on the frequency of biological traits of macrobenthos occurred at the transplant site, with a higher frequency of epifaunal predators and herbivores, and of organisms with longer life spans and larger body sizes. Sensitive and indifferent taxa were always higher in the transplant site than in the bare bottom control site, where opportunistic taxa continued to dominate. Ecological quality status measured through M-AMBI and HBFI indices showed a clear improvement in the transplant site. The rapid changes in benthos demonstrate that even relatively small-scale transplantation of dwarf eelgrass can restore faunal communities very rapidly. Full article