Search Results (79)

Research on the dynamic mechanisms driving the accumulation of anthropogenic marine debris (AMD) in highly dynamic environments, such as extensive sandy beaches, remains limited. Unmanned aerial vehicles (UAVs) can be used to map macro-marine litter in these environments over large temporal and spatial scales, but several challenges remain in their interpretation. In this study, secondary school students participated in a citizen science initiative, during which they identified, marked, and classified waste items using a series of UAV orthophotos collected along an 800 m extended Italian beach in different seasons. A specific training program and a collection of working tools were developed to support these activities, which were carried out under the constraints imposed by the COVID-19 pandemic. The accuracy of the citizen science approach was evaluated by comparing its results with standard in situ visual census surveys conducted in the same area. This methodology not only enabled an analysis of the temporal dynamics of AMD accumulation but also served an important educational function. The effectiveness of the learning experience was estimated using pre- and post-activity questionnaires. The results indicate a clear improvement in the students’ knowledge, interest, and awareness regarding marine litter, highlighting the potential of citizen science to both support environmental monitoring and promote sustainability education among younger generations. Full article

Microplastic pollution has gained attention in recent years due to its adverse impact on the environment. As a major threat to marine ecosystems and biota, the accumulation of microplastics along coastlines has become a growing concern. This study focused on quantifying and characterizing the presence, distribution, and composition of microplastics along the beaches of Romania and Bulgaria. Microplastics were extracted from beach sand samples using a saturated NaCl solution. The particles were then analyzed through FT-IR and DSC spectral analyses to identify their chemical composition. Sampling was conducted across several resorts along the Romanian and Bulgarian coastlines. The findings revealed varying concentrations of microplastics across different beaches, with Romanian beaches showing concentrations of between 40 and 213 particles per sample (470–2500 microplastics/kg), which were notably higher in areas like Mamaia and Costinești. On Bulgarian beaches, the average concentrations reached up to 137 particles per sample (1612 microplastics/kg), particularly in areas like Sunny Beach and Nessebar. Polyethylene (PE) was identified as the most prevalent polymer (55%), followed by polyamide (PA), polypropylene (PP), polyethylene terephthalate (PET), and polyurethane (PU). These polymers were linked to common sources such as packaging, textiles, and industrial products. Microscopic examination, combined with FT-IR and DSC spectral analysis, confirmed the plastic nature of the particles, revealing distinct chemical structures characteristic of each material type. This study underscores the widespread contamination of Romanian and Bulgarian beaches with microplastics, emphasizing the environmental risks to coastal ecosystems. The presence of synthetic polymers highlights the urgent need for policies targeting plastic waste management to mitigate the growing pollution in marine environments. Full article

The assessment of plastic pollution due to microplastics (MPs) and nanoparticles (NPs) was performed for the first time on water samples from four natural sites located near the beaches of Krk Island, Croatia, namely Melska, Črnika, rt Šilo, and Zala. MP and NP occurrence was investigated for the water samples collected during December 2022 and June 2023, using the bulk water method followed by filtration using stainless-steel sieves and the digestion process. Factor analysis and Spearman’s correlation revealed that the percentage of MP fragments correlated well with salinity (ρ = 0.76, p < 0.05) and the percentage of filaments correlated well with brown MPs (ρ = 0.80, p < 0.05). The monitoring of MPs throughout the sampling periods generally showed a decrease in abundance as the size increased. The presence of filaments indicated potential contributions from wastewater outlets, particularly from household washing machines, either directly from residents or tourists and abandoned fishing nets. The increased concentration of NPs over time could signify the continuous fragmentation of MPs in water due to natural degradation and biofilm formation on their surface. These findings could potentially be explained by the implemented plastic waste measures along the coast of Krk Island, which on 30 October 2024 was officially declared a zero-waste island. Full article

Tailings generated by mining account for the largest world-wide waste from industrial activities. As an element, copper is relatively uncommon, with low concentrations in sediments and waters, yet is very elevated around mining operations. On the Keweenaw Peninsula of Michigan, USA, jutting out into Lake Superior, 140 mines extracted native copper from the Portage Lake Volcanic Series, part of an intercontinental rift system. Between 1901 and 1932, two mills at Gay (Mohawk, Wolverine) sluiced 22.7 million metric tonnes (MMT) of copper-rich tailings (stamp sands) into Grand (Big) Traverse Bay. About 10 MMT formed a beach that has migrated 7 km from the original Gay pile to the Traverse River Seawall. Another 11 MMT are moving underwater along the coastal shelf, threatening Buffalo Reef, an important lake trout and whitefish breeding ground. Here we use remote sensing techniques to document geospatial environmental impacts and initial phases of remediation. Aerial photos, multiple ALS (crewed aeroplane) LiDAR/MSS surveys, and recent UAS (uncrewed aircraft system) overflights aid comprehensive mapping efforts. Because natural beach quartz and basalt stamp sands are silicates of similar size and density, percentage stamp sand determinations utilise microscopic procedures. Studies show that stamp sand beaches contrast greatly with natural sand beaches in physical, chemical, and biological characteristics. Dispersed stamp sand particles retain copper, and release toxic levels of dissolved concentrations. Moreover, copper leaching is elevated by exposure to high DOC and low pH waters, characteristic of riparian environments. Lab and field toxicity experiments, plus benthic sampling, all confirm serious impacts of tailings on aquatic organisms, supporting stamp sand removal. Not only should mining companies end coastal discharges, we advocate that they should adopt the UNEP “Global Tailings Management Standard for the Mining Industry”. Full article

This study focuses on the deposition of microplastics (MPs) on urban beaches along the central São Paulo coastline, utilizing advanced methodologies such as remote sensing, GNSS altimetric surveys, µ-Raman spectroscopy, and machine learning (ML) models. MP concentrations ranged from 6 to 35 MPs/m², with the highest densities observed near the Port of Santos, attributed to industrial and port activities. The predominant MP types identified were foams (48.7%), fragments (27.7%), and pellets (23.2%), while fibers were rare (0.4%). Beach slope and orientation were found to facilitate the concentration of MP deposition, particularly for foams and pellets. The study’s ML models showed high predictive accuracy, with Random Forest and Gradient Boosting performing exceptionally well for specific MP categories (pellet, fragment, fiber, foam, and film). Polymer characterization revealed the prevalence of polyethylene, polypropylene, and polystyrene, reflecting sources such as disposable packaging and industrial raw materials. The findings emphasize the need for improved waste management and targeted urban beach cleanups, which currently fail to address smaller MPs effectively. This research highlights the critical role of combining in situ data with predictive models to understand MP dynamics in coastal environments. It provides actionable insights for mitigation strategies and contributes to global efforts aligned with the Sustainable Development Goals, particularly SDG 14, aimed at conserving marine ecosystems and reducing pollution. Full article

This study investigates uranium (U) and thorium (Th) levels in surface beach sediments from the Central Gulf of Gabes (SE Tunisia), aiming to identify concentration zones, geochemical behaviors, and enrichment factors. U concentrations ranged from 0.71 to 38.00 mg/kg, exceeding Th levels, which ranged from 1.00 to 10.60 mg/kg. A positive correlation between U and Th indicates a common source, which is most likely phosphogypsum wastes, and similar geochemical behaviors. The central sector near Gabes’ fertilizer factories showed the highest U and Th concentrations, with factors such as proximity to industrial discharge, port structures’ influence, organic matter enrichment, low seawater pH, and high phosphorus levels affecting the spatial distribution of these elements. Thermochemical analysis suggests that U and Th exhibit parallel chemical behaviors in low-pH, phosphate-rich conditions. This is the first study to document U and Th presence in phosphogypsum-contaminated beach sediments in Gabes, underlining potential risks to the environment and human health. The findings of this work contribute to the international database of U and Th contamination in coastal sediments, providing essential data to support sustainable strategies aimed at safeguarding human health and preserving local environments affected by phosphate fertilizer industry pollution. Full article

Marine litter is a critical environmental issue, with beach litter being its most visible indicator. Despite severe pollution on Mediterranean beaches, Tunisia currently lacks a national beach litter monitoring program. To address this gap and support the development of such a program, particularly at pollution hotspots like urban beaches, we conducted a one-year study on six Tunisian beaches. We employed an innovative, accelerated multiple 10 m transect method tailored to highly polluted beaches, focusing on macro-litter (>2.5 cm). This method significantly reduces survey time compared to the standard 100 m approach while maintaining comparable pollution metrics, offering a practical and efficient solution for areas with high litter density. Our findings reveal an average litter density of 1.01 ± 1.08 pieces/m², with higher pollution in urban areas. Based on the Clean Coast Index (CCI), two beaches were classified as extremely dirty, one as dirty, two as moderately clean, and one as clean. Plastics (59.2%) and cigarette butts (21.1%) were the most prevalent pollutants, with single-use plastics comprising 52.5% ± 5.3% of total litter. Most of the litter (60.6%) originated from shoreline activities and poor waste management. These findings underscore the urgent need for a long-term national beach litter monitoring program. The integration of our accelerated transect method would enable efficient, effective surveys on highly polluted beaches, providing critical data to address litter sources and support targeted strategies for mitigating pollution and protecting Tunisia’s coastal ecosystems. Full article

This study aimed to characterize the temporal and spatial occurrence of microplastics on the beaches of the Caribbean coast of Limón, Costa Rica. The selected beaches comprise a stretch of 70 km, characterized by large environmental protection areas, agricultural and residential areas with low occupation density, urban areas, and port areas. Despite the great importance of the beaches for the country, studies related to solid waste pollution remain scarce on the Caribbean coast. The methodology consisted of conducting fieldwork in 2017 and 2019 to collect materials on five beaches and laboratory analyses for extraction using hypersaline solution and the quantification and characterization of microplastics based on type, size, and color. The results show that the beaches studied in the northwestern sector had the highest concentrations of microplastics, with emphasis on Cieneguita Beach and Airport Beach, with a predominance of pellets (56.7%) followed by fragments (21.8%). These beaches are inserted in a coastal stretch with a strong concentration of industrial, port, and airport activities. The lower occurrence of microplastics in the southeastern sector (Manzanillo and Gandoca) may be related to the greater number of preservation areas. With varying sizes, shapes, and colors, most microplastics had a worn appearance, which suggests reworking by coastal processes and subsequent deposition on the studied beaches. The impact of this type of pollution on the coast of Limón is notorious and shows the need for further research into the occurrence and distribution of microplastics on Caribbean beaches so that possible sources and damage to coastal ecosystems can be identified. Full article

Seaweed is a valuable natural resource, but drift or beach-cast seaweed is considered a waste product. Although seaweed is traditionally used as an organic amendment, vermicomposting has the potential to transform the material into valuable organic fertilizer, thereby enhancing its microbial properties. This study aimed to investigate the dynamics of the taxonomic and functional bacterial communities in seaweed during the vermicomposting process by high-throughput sequencing of 16S rRNA gene amplicons. Vermicomposting changed the composition of the bacterial communities, as indicated by the low proportion of bacterial taxa common to the bacterial communities in the raw seaweed and vermicompost (21 to 56 ASVs from more than 900 ASVs per sample type). The observed increase in taxonomic diversity (32% mean increase across sampling times) also affected the functionality of the bacterial communities present in the vermicompost. The diverse bacterial community showed enriched functional pathways related to soil health and plant growth, including the synthesis of antibiotics, amino acids, and phytohormones, as well as the degradation of bisphenol. In conclusion, in terms of microbial load and diversity, vermicompost derived from seaweed is a more valuable organic fertiliser than seaweed itself. Full article

Environmental pollution from plastic debris is raising concerns not only for the vulnerability of marine species to ingestion but also for potential human health hazards posed by small particles, known as microplastics. In this context, marine areas suffer from a lack of constant shoreline cleanups to remove accumulated debris, preventing their degradation and fragmentation. To establish optimal strategies for streamlining plastic recovery and recycling operations, it is important to have a system for recognizing plastic debris on the beach and, more specifically, for identifying the type of polymer and mapping (e.g., topologically assessing) the distribution of plastic debris on shoreline sands. This study aims to provide an operative tool finalized to perform an in situ detection, analysis, and characterization of plastic debris present in the coastal environment (i.e., beaches), adopting a near-infrared (NIR)-based hyperspectral imaging (HSI) approach. In more detail, the possibility of identifying and classifying polymers of plastic debris by NIR-HSI in three different areas along the Pontine coastline of the Lazio region (Latina, Italy) was investigated. The study focused on three distinct beaches (i.e., Foce Verde, Capo Portiere, and Sabaudia), each characterized by a different type of sand. For each location, the adopted approach allowed for the systematic classification of the various types of plastic waste found. Three Partial Least Squares Discriminant Analysis (PLS-DA) classification models were developed using a cascade detection strategy. The first model was designed to distinguish plastics from other materials in sand samples, the second to detect plastic particles in the sand, and the third to classify the type of polymer composing each identified plastic particle. Obtained results showed that, on the one hand, plastics were correctly detected from sand and other materials (i.e., sensitivity = 0.892–1.000 and specificity = 0.909–0.996), and on the other, the recognition of polymer type was satisfactory, according to the performance statistical parameters (i.e., sensitivity = 1.000 and specificity = 0.991–1.000). This research highlights the potential of the NIR-HSI approach as a reliable, non-invasive method for plastic debris monitoring and polymer classification. Its scalability and adaptability suggest possible future integration into mobile systems, enabling large-scale monitoring and efficient debris management. Full article

Cigarette butts (CBs) are a major source of persistent pollution in coastal ecosystems, introducing harmful chemicals and microplastics into the environment. This study assesses the ecotoxicological impact of CB leachates on Marbella Beach, Chile, by analyzing the metal contamination and its phytotoxic effects on Lactuca sativa and Lolium perenne. Three scenarios were evaluated: CBs alone, CBs mixed with sand, and sand alone. Leachate analysis revealed significant concentrations of iron and zinc, with higher toxicity observed in scenarios involving CBs. Ecotoxicological assays demonstrated that cigarette butt leachates severely inhibited seed germination and plant growth, particularly in Lactuca sativa, which showed greater sensitivity compared to that of Lolium perenne. The results underscore the partial mitigating role of sand, although it was insufficient to prevent the toxic effects of CBs. The persistence of cellulose acetate in the environment and the continued release of hazardous chemicals highlight the ecological risks posed by cigarette butt pollution. These findings emphasize the need for improved waste management strategies and the development of biodegradable cigarette filters to reduce environmental contamination in coastal areas. Full article

Sandy beaches along the North African Mediterranean coast face significant challenges due to accumulating human-made debris (marine litter) and natural debris (beach wrack). Addressing these issues requires awareness of pollution and the ecological relevance of beach wrack, along with stakeholder involvement. This study quantifies beach litter pollution and identifies sources in Tunisia, Morocco, and Egypt, serving as a basis for ecosystem service assessments and further integration into the implementation of mitigation measures. High levels of plastic litter were found, ranging from 1565 to 7778 pieces per 100 m of beach length. Shoreline activities, tourism, and poor waste management were identified as the main sources of litter, with single-use plastics accounting for 41.1% of the debris. Further objectives include providing a list of suitable ecosystem services and developing management scenarios. Local stakeholders’ perceptions of the impact of marine litter and beach wrack on ecosystem services were assessed using a scenario approach and different formats (i.e., stakeholder workshop, interviews, teaching). Stakeholders highlighted the negative impact of marine litter on cultural services, while beach wrack was perceived positively for regulating and maintenance services. This approach enhances awareness, interest, and knowledge in data-scarce regions, serving as a valuable tool for stakeholder engagement, elicitation of stakeholder knowledge, and teaching (i.e., learning tool). Limitations include the subjectivity of the results, limited participant reach, and dependence on stakeholder knowledge. Integrating stakeholder-based ecosystem service assessments into measure planning and decision making is essential for effective litter management and beach conservation efforts. Full article

This study involves an integrated and innovative approach employing high-frequency monitoring, which is rare in studies focusing on solid waste on beaches. Eight drone flights were performed over a tourist beach in the Colombian Caribbean to achieve two main objectives: (i) to quantify the changes in marine macro-litter (>2.5 cm) density, focusing on the differences between the period when the beach was closed due to the COVID-19 pandemic and the subsequent reopening period; and (ii) to map changes in the abundance of marine macro-litter on the coast, with an emphasis on single-use waste. The number of items of litter on the beach increased 9-fold between the closed and reopening periods, and the main items found were crisp/sweet packets (n = 304, 13% of the total waste), plastic cups (n = 248, 11%), and expanded polystyrene (food containers) (n = 227, 10%). The factors contributing to the presence and distribution of the marine macro-litter were tourists, the use of the beach, and offshore wind direction. The results revealed that Salgar Beach can be considered a marine macro-litter exporter since waste is incorporated into the longshore current and redistributed either to nearby beaches or the ocean. This study emphasizes the potential for using drone images in an integrated approach to monitoring the presence of marine macro-litter as well as the efficiency of programs for combatting litter at sea. Full article

This study investigates the occurrence and characteristics of macroplastic and polymer microparticles in the Urias coastal lagoon’s beach sediments, in northwest Mexico. Coastal lagoons, productive and vulnerable ecosystems, are impacted significantly by anthropogenic activities, leadings to their pollution by various contaminants, including plastics. Our research involved sampling sediments from four sites within the lagoon that were influenced by different human activities such as fishing, aquaculture, thermoelectric power plant operations, industrial operations, and domestic wastewater discharge. Our methodology included collecting macroplastics and beach sediment samples, followed by laboratory analyses to identify the plastic debris’ size, shape, color, and chemical composition. The results indicated a notable presence of macroplastic items (144), predominantly bags, styrofoam, and caps made of polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). The polymer microparticles were mainly fibers, with cotton and polyester as the most common polymers, suggesting a significant contribution from clothing-related waste. The dominant colors of the microparticles were blue and transparent. High densities were observed in areas with slower water exchange. Our findings highlight the urgent need for better waste management practices to mitigate plastic pollution in coastal lagoons, preserving their ecological and economic functions. Full article

Coastal beaches are vulnerable to microplastic pollution originating primarily from terrestrial and marine sources or the in situ weathering of plastic waste. The present study investigates the effects of rainfall events on the composition and diversity of microplastics on beaches in Xiamen City on a short-term scale. In the results, the quantity of microplastics in beach sediments was 245.83 ± 11.61 items·kg⁻¹ (mean ± standard error). The abundance of microplastics did not differ after each rainfall event but significantly decreased after multiple rainfall events. When the diversity of microplastics in the coastal area was evaluated, the Shannon-Wiener index and Pielou’s index also decreased from 3.12 and 0.64 to 2.99 and 0.62, respectively, after multiple rainfall events. Rainfall had varying effects on microplastics depending on their size and shape, with particles smaller than 500 μm experiencing pronounced reductions. There was a significant negative correlation between the abundance of microplastics and the grain size of sand, but a positive correlation with sediment moisture content. We encourage the consideration of the potential impact of rainfall events during sample collection to ensure the reliability of the data. We also recommend using diversity indexes to help in understanding the influence of physical processes on microplastic distribution and their mechanisms. Full article