A rapid assessment of litter magnitudes and impacts along the Torre Guaceto marine protected area (Brindisi, Italy)

Marine litter pollution in inhabited and uninhabited Lakshadweep islands, Indian Ocean

The Lakshadweep archipelago, located in the Arabian Sea off India's southwestern coast, is renowned for its rich biodiversity and vibrant coral reefs. However, the region faces a growing environmental threat from marine debris, particularly plastic waste, which poses a significant challenge to its delicate ecosystem. To identify potential sources of pollution, we assessed environmental quality and ecological risk using indices such as the Clean Coast Index (CCI), Plastic Abundance Index (PAI), and Pollution Load Index (PLI). We also analyzed the spatial distribution of marine litter on Lakshadweep's beaches and mapped the annual wind direction. The study, conducted across six islands, recorded 3933 plastic litter items, with an average abundance of 0.77 ± 0.33 items/m2, making up 82.9 % of the total litter. The high mean values of CCI (17.98), PAI (5.39), and PLI (34.25) indicate severe ecological risk and critical pollution levels along the Lakshadweep coastline, driven by extensive macroplastic accumulation. Furthermore, the study highlights the influence of wind patterns on plastic movement across the islands. These findings provide essential insights for developing effective strategies to manage and mitigate marine litter, contributing to the broader effort to combat plastic pollution in the region.

Abundance, distribution, and seasonal variation of marine litter on the beaches of central Vietnam

This study investigates the abundance, distribution, and seasonal variation of marine litter across beaches in central Vietnam, using the Clean Coast Index (CCI) and Hazardous Index (HI) to assess pollution levels. A total of 16,118 litter items were recorded across 21 sampling sites, with plastics overwhelmingly dominant (96.48 %), followed by rubber (2.02 %) and paper (1.10 %), while glass, wood, and metal were minimal. The results reveal a significant seasonal influence on litter density, with higher accumulation during the rainy season due to increased runoff and riverine transport. The average litter density increased from 0.06 items/m2 in the dry season to 0.14 items/m2 in the rainy season (2022) and from 0.06 items/m2 to 0.11 items/m2 (2023). Statistical analyses using PCA demonstrated that 93.40 % of the total variance is explained by the first two principal components, highlighting the impact of seasonal and spatial pollution dynamics. HCA identified distinct site groupings based on pollution intensity, reinforcing the influence of urbanization, tourism, and human activities on litter accumulation. While most beaches were classified as "very clean to clean", urban and high-tourism areas exhibited increased pollution, emphasizing the need for targeted waste management efforts. These findings underscore the urgent necessity for enhanced waste management policies, stricter regulations on plastic usage, improved community engagement, and continuous monitoring to mitigate marine pollution and safeguard coastal ecosystems in Vietnam.

Multidimensional risk assessment of marine litter pollution in the ecologically fragile coral atolls of India

Marine litter (ML), predominantly plastic, threatens oceanic biodiversity and ecosystem functioning globally. However, limited knowledge exists about its impact on India's coastal areas, particularly the Lakshadweep Islands, the nation's sole coral atolls. Within this frame of reference, the present study comprehensively investigated the distribution, abundance, typology, and ecological risks associated with ML across 28 beaches and three lagoon reef stations on Kavaratti Island. A total of 32,710 litter items, divided into 11 categories, were found with an average litter density of 0.82 ± 0.80 items/m2. Plastic litter emerged as the most prevalent category across the study area, constituting 63.7% of the total, and public littering was identified as the primary source (43%). Assessments of environmental quality and ecological risk, employing indices like the Clean Coast Index (CCI), Plastic Abundance Index (PAI), Hazardous Litter Index (HLI), Pollution Load Index (PLI), and Environmental Status Index (ESI), identified the Lakshadweep coastline as being at risk due to litter pollution and hazardous litter abundance. The mean concentration of trapped litter on the coral reef was estimated at 1.73 ± 0.46 items/m2, with a PLI value of 53.4, indicating an alarming ecological risk and highly perilous condition for the lagoon reef ecosystem. Approximately 5.94% ± 0.18% of coral colonies, particularly of the Porites genus, were found in contact with ML, with a significant proportion displaying signs of disease and tissue loss (59.37%), and partial bleaching or pale (14.86%). The results highlight the growing threat of litter to beach and coral communities, emphasizing the urgent need for effective regional litter management, strengthened policies for banning and phasing out single-use plastics in Lakshadweep, and efficient transportation of non-biodegradable waste to authorized recyclers on the mainland.

Microplastic pollution from pellet spillage: Analysis of the Toconao ship accident along the Spanish and Portuguese coasts

In December 2023, 25 tons of pellets were lost by the Toconao ship in the Northwest Atlantic Ocean in front of the Portuguese coast. In this work, a coastal stretch of 633 km in Asturias and Galicia (Spain) and Northern Portugal was investigated to assess pellets' concentration on 31 beaches. Field surveys were carried out in March 2024 and focused on sampling plastic pellets deposited along the shoreline. All the 7263 sampled pellets were characterized by size, degradation level, and color, while one subset was characterized by weight (40 % of the total) and another subset by polymer type (15 % of the total) using FT-IR spectroscopy. The results reveal that 94 % of the surveyed sites containing pellets, whereas the concentration values vary significantly among beaches, ranging from 0 to 40.3 pellets/kgdw. By combining the accounted variables, it emerges that 48.0 % of the collected pellets can be linked to the Toconao spill.

Assessment of coastal litter trends in tourist vs. non-tourist beaches: A case study from Indian coastal smart city

Coastal ecosystems are increasingly threatened by the accumulation of marine litter globally. Limited data availability along India's eastern coast hinders targeted mitigation efforts. This study assesses coastal litter along Visakhapatnam, a smart city on India's eastern coast, using the NOAA shoreline debris protocol. Litter assessments at 12 sites before and after the monsoon season revealed high mean litter densities (2.66 ± 0.31 items m-2 before monsoon, 2.03 ± 0.29 items m-2 after monsoon), exceeding the global average by twofold and the national average by five-fold. The tourist beaches saw a 63 % litter reduction after monsoon due to the implementation of better waste management practices, while non-tourist beaches saw a 16 % increase, highlighting disparities in waste management practices. Plastic comprised 86 % of litter, exceeding the global mean proportion (85 %) in marine litter. Alarmingly, 50 % of tourist beaches and all non-tourist beaches were classified as "extremely dirty" by the Clean Coast Index. Land-based influx through stormwater drains was identified as the primary source of litter. This study provides critical baseline data for India's eastern coast, emphasizing the urgent need for targeted interventions, including improved stormwater management and community engagement, to mitigate the escalating marine litter crisis. Further, the findings and recommendations provide valuable insights for managing plastic pollution in coastal cities with similar characteristics, particularly those influenced by monsoons and tourism.

Marine macrolitter and cigarette butts hazard multiple-use marine protected area and fishing community at Brazil

Wide marine litter (ML) contamination impacts human health and economic sectors including fishing, navigation, and tourism. Perequê beach, Brazil, is an authentic fishing community within a touristic multiple-use marine protected area. However, no ML contamination monitoring were so far performed in the region. This study evaluated the spatiotemporal abundance, composition, sources, and associated ML hazards at Perequê beach using a multi-index approach. The 2579 items (0.64 ± 0.72 items.m-2) yielded a high contamination level (CCI = 12.6 ± 14.4) with plastic (44.6-50.9 %) and cigarette butts (20.6-28.4 %) prevalence, while primary sources were smoking (cigarette butts, lighters, others-21.2-30.1 %) and packaging (17.8-22.8 %). Levels of pollutants leaked from cigarette butts (CBPI = 30.5 ± 47.5) and hazardous items (HALI = 3.06 ± 2.64) were among the highest globally. Heightened levels occurred in summer, at dry sand strip, where short-term buoyant items prevailed. Multi-indexing approaches offer valuable insights for local authorities to implement mitigation programs, while contributing to global discussions, promoting awareness, and facilitating replicability.

Marine litter along the Peruvian coast: spatiotemporal composition, sources, hazard, and human modification relations

Marine litter (ML) represents an escalating environmental issue, particularly in Latin America, where comprehensive studies are scarce despite critical solid waste management challenges and continuous human modification occurring on the coasts. To contribute to the knowledge of ML in the southeast Pacific, this study examined contamination across 10 beaches on Peru's extensive coast. Overall, ML contamination was categorized as moderate (with an ML concentration of 0.49 ± 0.64 items∙m-2), while significantly differing between summer (dirty with an ML concentration of 0.56 ± 0.66 items∙m-2) and winter (moderate with an ML concentration of 0.47 ± 0.60 items∙m-2). Three beaches were extremely dirty (concentrations of ML exceeded 1.0 items∙m-2). Predominant materials, items, and sources were plastic, cigarette butts (CBs), and mixed packaging. The Peruvian coast faced CB leachate impact (CBPI = 3.5 ± 3.5), reaching severe levels on two beaches, with considerable hazardous litter (HALI = 3.0 ± 2.9). Additionally, a higher degree of human modification was associated with higher ML levels along the coast.

A set of guidelines as support for the integrated geo-environmental characterization of highly contaminated coastal sites

The knowledge of geomorphodynamic aspects is crucial for understanding marine and coastal processes/dynamics as well as for characterizing coastal environments heavily affected by anthropogenic activities. To provide a framework of analysis that can be applied in a consistent way for the geo-environmental characterization of highly contaminated coastal sites, in this paper a set of operational guidelines is proposed. Special attention is given to the role of geomorphological-based surveys and analyses in defining (i) the site-specific geological model of the investigated site, (ii) the anthropogenic impacts on marine and coastal sediments, (iii) the expected morphodynamic variations induced by climate change and anthropogenic interventions, (iv) tailored dissemination activities and community engagement plans. Then, an evaluation of the state of the art of activities already performed for the characterization of the coastal contaminated sites located in the Apulia region (southern Italy) is provided. The outcomes of this research are also provided in the form of infographics to favor their dissemination among communities and stakeholders.

Plastic pollution on Moroccan beaches: Toward baselines for large-scale assessment

In Africa, Morocco is the 10th largest producer of plastic. The severity of this plastic has attracted increasing amounts of attention in the Moroccan Atlantic and Mediterranean in recent years. However, at the national level, there is limited knowledge of plastic pollution. To obtain an exhaustive and comprehensive evaluation of plastic pollution levels in Morocco, large-scale monitoring is needed on all the coasts of the country. In this context, this paper examined the composition, abundance, distribution, source and quality of beaches on two Moroccan coasts using four beach quality indices along 29 beaches. During two seasons, a total of 72,105 items were counted. The mean litter abundance was 0.31 items/m2, and the Mediterranean beaches were more dense than the Atlantic beaches. In particular, litter density was greater in spring (0.35 items/m2) than in summer (0.29 items/m2). The data indicate considerable differences in the density of marine debris according to the seasonality, beach typology and presence of rivers. Hazardous litter items were collected along both Moroccan coasts, constituting 8.41 % of the total collected items, with a mean of 0.026 items/m2. The use of environmental indices allowed us to classify Moroccan beaches as "moderate cleanliness", "moderate abundance" of plastics, "moderately safe" presence of hazardous litter and "mediocre" environmental status. The findings of the present study indicate that the sources of litter on both Moroccan coasts come mainly from recreational activities and dumping. The waste management practices recommended for Moroccan beaches include reducing sources, mitigating mitigation measures and changing littering behavior.

Microplastics in inland and offshore sediments in the Apulo-Lucanian region (Southern Italy)

Inland and offshore sediments from Southern Italy were studied in order to evaluate the occurrence and nature of microplastics (MPs). Inland sediments were collected in the Bradano and Basento rivers (Apulo-Lucanian region, Southern Italy), while offshore sediments were collected on the continental shelf near Bari (Adriatic Sea) and Metaponto (Ionian Sea). MPs were detected and characterized using optical microscopy, micro-Fourier-Transform Infrared spectroscopy (μ-FTIR) and micro-Raman analyses. The number of MPs present varied between 144 and 1246 kg-1 of dry sediment (468.8 ± 410,7 MPs kg-1) with a predominance of black fibers; no correlation emerged between MPs and sediment grain size. In river sediments, the occurrence of MPs is associated with local pollution, whereas the offshore occurrence of MPs depends on seasonal river flow and submarine canyons. Compositional analyses suggest that the main source of MPs in the studied sediments is sewage discharge from residential areas.

Assessing marine macrolitter on the coastline of the Asterousia Biosphere Reserve: Insights from a community-based study

Even in pristine and remote environments of the Mediterranean, marine litter is building up threatening habitats and species and inhibiting sustainable development. The present study reports the findings of beach litter surveys carried out by 250 local community members in nine sites along the coastline of the Asterousia Biosphere Reserve, situated in the southernmost end of Europe. The average recorded litter density along these sites amounted to 125 items per 100 meters of coastline (range: 22-510) and to 0.05 items per square meter of beach (range: 0.01-0.13). Only two of the nine surveyed beaches were found to be in good environmental status, in compliance with the European threshold value for beach litter. The other seven studied beaches surpassed the European threshold value. The primary sources of the litter identified in the study can be attributed to unsustainable practices and inadequate waste management by individuals, communities and municipalities using the coastal and marine environment. Additionally, unsustainable waste management practices within the agricultural sector were also found to be a significant contributor to marine litter pollution.

The octopus pot on the North Atlantic Iberian coast: A plague of plastic on beaches and dunes

This baseline focuses on the octopus pot, a litter item found on the North Atlantic Iberian coast. Octopus pots are deployed from vessels in ropes, with several hundred units, and placed on the seabed, to capture mostly Octopus Vulgaris. The loss of gears due to extreme seas state, bad weather and/or fishing-related unforeseen circumstances, cause the octopus pots contaminating beaches and dunes, where they are transported by sea current, waves and wind actions. This work i) gives an overview of the use of octopus pot on fisheries, ii) analyses the spatial distribution of this item on the coast, and iii) discusses the potential measures for tackling the octopus pot plague on the North Atlantic Iberian coast. Overall, it is urgent to promote conducive policies and strategies for a sustainable waste management of octopus pots, based on Reduce, Reuse and Recycle hierarchical framework.

Decoding plastic pollution in the geological record: A baseline study on the Caribbean Coast of Colombia, north South America

This study presents the first report of plastics in the geological record (rocks and formations composed of plastics) along the central Caribbean Coast of Colombia, northern coast of South America. These novel records of pollution include two rock types (plastiglomerates and quartz plastisandstones), two altered plastic types (pyroplastics and plasticrusts), two soil types (plasticlasts and anthrosols), and a series of artifacts (fossils) found near human settlements. All of them were analyzed using Fourier Transform Infrared (FTIR) spectroscopy. Polyester, high-density polyethylene, and copolymers of alkyl acrylates or methacrylates were identified as the principal polymers forming these rocks. This research provides new insights into the petrology of these emerging new forms of pollution, for which humans are primarily responsible for their generation and distribution. Similarly, the results presented emphasize that plastics are generating a deluge of pollutants in terms of variety and volume, overwhelming natural environments globally. Controlling or even eliminating their use has become one of the most significant challenges of the 21st Century.

The nauticAttiva project: A mobile phone-based tool for the citizen science plastic monitoring in the marine and coastal environment

Plastic pollution is involving large coastal areas of the Mediterranean Sea. Innovative methods of plastic monitoring can be addressed through the citizen science approaches integrated with mobile phones. On the other hand, the availability of mobile phones is increasing among several users. Mobile phones can be integrated with a web mobile app, which allows to collect a lot of data for extended areas and in a short temporal range. In this study, the web service of iNaturalist was applied to implement a mobile phone-based tool to collect pictures of plastic items. At present, the web mobile app has been used to collect pictures of plastic debris in the Mediterranean Sea. Results were compared with the Mediterranean hydrodynamic regime, to highlight the pathways and densities of the plastic items. The proposed mobile phone-based tool represented a citizen science approach useful for the acquisition of plastic observations in the marine and coastal environment.

Addressing the challenge of marine plastic litter in the Moroccan Mediterranean: A citizen science project with schoolchildren

In this study, based on data collected by citizen science, we studied the abundance, spatial and temporal distribution of marine litter in three beaches of the Moroccan Mediterranean. A total of 14,042 litter items were collected with an average abundance of 0.58 items/m². The most of litter were composed of anthropic polymeric materials, representing 74 % of the total litter collected. Plastics account for the majority of the items collected and are mainly caps/lids, crisp/sweet packets, plastic/polystyrene, cigarette butts and small plastic bags. Litter abundance displayed significant seasonal differences, with the highest during summer. Tourism and poor waste management practices are the major sources of plastic on the beaches surveyed. The use of the Clean Coast Index (CCI) and the Plastics Abundance Index (PAI) permits the classification of the three beaches in the Moroccan Mediterranean as a "moderately clean" coastal area with a "very high abundance" of plastics. In addition, the Hazardous Items Index (HII) allows classification of the region as highly polluted by hazardous litter. Best management measures are needed to promote the environmental quality of the beaches of the Moroccan Mediterranean.

What Are Lake Beaches Made of? An Assessment of Plastic Beach Litter on the Shores of Como Bay (Italy)

Plastic waste dispersion is a well-recognized environmental threat, despite continuous efforts towards improving waste disposal management over the last few decades. Plastic litter is known to strongly impact upon water bodies and shorelines, affecting the health of ecosystems and impacting upon the aesthetic value of sites. Moreover, plastic waste that is abandoned on beaches contributes towards different degradation processes that potentially lead to the formation of secondary microplastics (MPs), with likely cascade effects upon the whole ecosystem. In this view, this study aims to characterize the plastic beach litter found on the shores of the western basin of Como Lake (Italy) to better understand the origin of MPs in littoral sediments, including the recognition of object typologies and the chemical characterization of polymers using Fourier-transformed infrared analysis (FTIR). The results highlighted that the most abundant polymers on beaches are polypropylene (PP) and polyethylene (PE), representing 73% of the collected polymers. This confirms that floating, low-density polymers are more likely to accumulate on beaches. Moreover, almost 66% of litter is represented by commonly used manufactured items (disposable objects, packaging, and everyday items). This evidence, combined with the analysis of the main environmental features of the sampling sites (the main winds, distance to urban areas, and the presence of tributaries) indicate that abundance of beached litter is mainly linked to beach accessibility and the local winds. These results highlight that multiple factors affect the environmental fate of plastic litter and give insights into the assessment of secondary microplastics in beach sediments.

Operational use of multispectral images for macro-litter mapping and categorization by Unmanned Aerial Vehicle

The use of Unmanned Aerial Systems (UAS, aka drones) has shown to be feasible to perform marine litter surveys. We operationally tested the use of multispectral images (5 bands) to classify litter type and material on a beach-dune system. For litter categorization by their multispectral characteristics, the Spectral Angle Mapping (SAM) technique was adopted. The SAM-based categorization of litter agreed with the visual classification, thus multispectral images can be used to fasten and/or making more robust the manual RGB image screening. Fully automated detection returned an F-score of 0.64, and a reasonable categorization of litter. Overall, the image-based litter density maps were in line with the manual detection. Assessments were promising given the complexity of the study area, where different dunes plants and partially-buried items challenged the UAS-based litter detection. The method can be easily implemented for both floating and beached litter, to advance litter survey in the environment.