Mapping marine debris across coastal communities in Belize: developing a baseline for understanding the distribution of litter on beaches using geographic information systems.

Monitoring of marine debris (also known as marine litter) is an essential step in the process to eradicate ecological dangers in marine ecosystems caused by humans. This study examines marine debris in the Caribbean country of Belize using geographic information systems (GIS) to develop (1) a detailed data library for use on handheld Global Positioning System (GPS) units and tablets with mobile mapping applications for deployment in the field and (2) a freely available, online mapping portal to share data with Belizeans to encourage future citizen science efforts. Four diverse communities were targeted ranging from larger more populated towns, to smaller villages across central and southern Belize: San Pedro, Caye Caulker, Punta Gorda, and Monkey River. Fieldwork was conducted over 1 month, during which data points were collected in 50-m surveys followed by debris cleanup and removal. Features in our database included material, quantity, item, brand, and condition. Over 6000 pieces of debris were recorded in GIS for further analysis, and 299 gal of debris were removed from the shores of Belize. The most abundant form of debris observed was plastic (commonly bottles) across all locations; plastic comprised 77.6 % of all debris items observed. Through GIS, a detailed snapshot understanding of debris patterns across multiple settings in Belize was documented. Ongoing collaborations with local organizations in Belize have demonstrated significant interest and utility for such GIS approaches in analyzing and managing marine debris. The data, methodology, visual representations, and online mapping platform resulting from this research are a first step in directly supporting local Belizean community advocacy and policy, while contributing to larger institutional strategies for addressing marine debris issues in the Caribbean.

Beach litter deposition and turnover, effects of tides and weather, and implications for cleanup strategies: A case study in the Lofoten archipelago, Norway.

Plastic pollution is ubiquitous in the marine environment. Beach cleanups are considered a cost-effective mitigative measure with generally few negative environmental impacts. Beached litter is not static, however, and may wash back out to sea or be buried, meaning it is only temporarily available for cleanup. We studied deposition and turnover of litter on three Arctic beaches in Lofoten, Norway, biweekly for 31 months. The mean estimated daily deposition rate was 10 items/100 m, with a median residence time of 99 days. Both processes were impacted by seasons and weather and varied both spatially and temporally. Strong winds during the fall increased litter influx and onshore winds contributed to its loss. Heavier objects and those higher on the beach persisted longer yet were still subject to turnover. Snow temporarily buries litter but protects it in the long run. Given the turnover of litter, frequent (albeit smaller) cleanups can readily remove 3-4 times more litter from circulation in the environment than larger, infrequent cleanups. With limited resources, it is recommended to prioritise late fall cleanups.

Discernible decline in macroplastic litter inputs to the central eastern Red Sea shoreline during the COVID-19 lockdown.

Plastic debris accumulating on beaches pose a major threat to marine ecosystems. Unexpected events affecting human operations, such as the COVID-19 pandemic, which prompted governments to implement safety measures and restrictions, can serve as an unplanned investigation of anthropogenic pressure on the marine environment. This study aimed to explore deviations in macroplastic delivery rates to the central eastern Red Sea shoreline during three distinct population mobility periods: before, during, and after COVID-19 restrictions, spanning from January 2019 to June 2022. We observed a 50 % reduction in the estimated macroplastic delivery rates during the lockdown, followed by a 25 % increase after restrictions were eased. Seasonal variations in delivery rates were also observed, with higher values during the winter monsoon. Reduced shoreline litter delivery during the pandemic highlights human operations as a cause of macroplastic litter and suggests the potential of temporary measures to reduce plastic pollution in the coastal environment.

Beach litter composition, distribution patterns and annual budgets on Novaya Zemlya archipelago, Russian Arctic.

Beached macrolitter (>2,5 cm) abundance and composition in the Russian (Eastern) part of the Barents Sea and the adjacent part of the Kara Sea was assessed for 2021-2023. Average densities of beach litter on the coasts are 675 items/100 m and 37 kg/100 m (0.27 items/m2 and 0.015 kg/m2). Annual litter budgets for Cape Zhelaniya beaches are 0.49 items/m2 per year and 0.023 kg/m2 per year. The northernmost tip of Novaya Zemlya is shown to be a beach litter accumulation hot-spot on Novaya Zemlya archipelago, where litter is brought by surface currents and trapped by sea ice margins. Up to 80 % of beached marine macrolitter is made of plastics, originating from vessels. A certain accumulation strip of a beach was identified (14 m - 27.5 m distance from the waterline), and significance of the beach backshore was shown in litter accumulation. Beach litter accounting methodologies on the Arctic beaches are discussed.

Assessment of marine litter on the Fields Peninsula, King George Island, Antarctica.

The study presents the results of the survey of beached litter on the two opposite shores of the Fields Peninsula (King George Island) conducted during the austral summer seasons of 2022 and 2023, as part of the 67th and 68th Russian Antarctic expeditions. Beaches situated on the coast of the Drake Passage were much more polluted compared to the beaches on the Maxwell Bay side. Plastic accounted for 86 % of all found items on the shores of the Drake Passage, with the majority of items related to fisheries or shipping. On the Maxwell Bay beaches, only 36 % of litter was plastic, with other categories like wood and metal dominating the total number. The average density of marine litter is 0.32 items/m (0.017 items/m2), comparable to other similar surveys conducted on Antarctic islands; however, this is at least 15-20 times lower than beach litter densities in the Arctic.

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.

Marine beach litter monitoring strategies along Mediterranean coasts. A methodological review.

Marine beach litter (MBL) represents a serious issue for marine life, coastal ecosystems, human health and several economical activities. The Mediterranean Sea is a semi enclosed basin particularly vulnerable to this problem. Its coasts are threatened by critical anthropogenic pressures that sum up with intensive fishing and shipping, and the slow turnover of its waters. In the last decades, several scientific and participative initiatives have been conducted to study, monitor and clean-up shorelines. These studies were generally characterized by differences in timing and frequency of the surveys, as well as in litter sampling, classification and analysis. This paper presents a systematic review of current literature concerning MBL monitoring strategies along the Mediterranean coasts. Scopus indexed studies are analysed to identify discrepancies and similarities among the applied protocols, understand where current gaps lie, and point out what would be needed to develop a basin-scale efficient monitoring for the Mediterranean Sea.

Assessment of national beach litter composition, sources, and management along the Indian coast - a citizen science approach.

The present study evaluates the Pan-India beach litter density (items/m2), weight (kg/m2), composition (%), and probable sources based on the citizen science approach. A total of 33 beaches in 2019 and 30 beaches in 2021 were studied. Based on density, the national beach litter average was 0.475± 0.51 and 0.3 ± 0.4 items/m2 in 2019 and 2021, respectively. Plastic was the dominant litter type (65 % in 2019; 74 % in 2021) and Single-Use Plastics (SUPs) were predominant. Based on Clean-Coast Index, six beaches in 2019 and three beaches in 2021 are classified as "extremely dirty". The principal (∼60 %) sources of litter were tourism and public littering. Improving solid waste management, stringent implementation of environmental legislation, leveraging the polluter pays principle, monitoring the effectiveness of SUPs ban, generating awareness, and beach clean-up at regular intervals by engaging the public, educational, and non-governmental organizations will improve and sustain the cleanliness of beaches.

Three-dimensional evaluation of beaches of oceanic islands as reservoirs of plastic particles in the open ocean.

The quantification of plastic debris on beaches has been extensively used as an indicator of plastic pollution in the marine environment. However, most efforts have focused on surface layers, with few investigations looking deeper into the substrate, thus underestimating total standing stocks. Such information is crucial to improve our understanding of where plastic accumulates in the oceans. In this study, we investigated the three-dimensional distribution of plastic (>1 mm) in three sandy beaches located in oceanic islands of the North Atlantic (Azores and the Canary Islands) that are known to accumulate significant quantities of small plastic debris at the surface layer. On each beach, we collected a total of 16 sediment cores down to 1 m depth, from the high tide line up to the backshore following a stratified random sampling design spread across four different levels across the beach. Samples were taken every 10 cm down to 1 m into the sand. Our results revealed the presence of plastic items in the deepest layers with subsurface layers accounting for 84 % of the total plastic abundance and with a similar pattern in terms of size, shape, colour and composition. Furthermore, we found increasing plastic concentrations towards the upper levels of the beach, indicating longer term accumulation in the backshore. Collectively, this study suggests that the plastic items reaching sandy beaches of the Macaronesia are being incorporated into its deepest layers, acting as reservoirs of plastic in the open ocean.

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.

Dune plants as a sink for beach litter: The species-specific role and edge effect on litter entrapment by plants.

Anthropogenic litter accumulates along coasts worldwide. In addition to the flowing litter load, wind, sea currents, geomorphology and vegetation determine the distribution of litter trapped on the sandy coasts. Although some studies highlighted the role of dune plants in trapping marine litter, little is known about their efficiency as sinks and about the small-scale spatial distribution of litter across the dune area. Here, we explore these gaps by analysing six plant species widespread in Mediterranean coastal habitats, namely Echinophora spinosa, Limbarda crithmoides, Anthemis maritima, Pancratium maritimum, Thinopyrum junceum, and Salsola kali. The present study analyses for the first time the capture of litter by dune vegetation at a multi-species level, considering their morphological structure. Data on plastic accumulation on dune plants were compared with unvegetated control plots located at embryo-dune and foredune belts. We found that dunal plants mainly entrapped macrolitter (> 0.5 cm). Particularly, E. spinosa, L. crithmoides, A. maritima and P. maritimum mostly accumulated litter in the embryo dune while T. junceum and S. kali entrapped more in the foredune area. Moreover, beach litter was mainly blocked at the edge of the plant patches rather than in the core, highlighting the 'Plant-edge litter effect'. As A. maritima and S. kali entrapped respectively more litter in embryo and foredune habitats, these species could be used to monitor and recollect litter. In this light, our findings provide further insight into the role of dune plants in the beach litter dynamics, suppling useful information for beach clean-up actions.

From source to sink: A comparative study of streamside and beach litter in the Black Sea.

The increasing amount of marine litter pollution and its impact on the marine environment raises global concern. This study aims to reveal the effect of streams on marine litter density and composition. A total of ten stations on the southeastern Black Sea and six stations on the Manahoz stream were seasonally surveyed. The litter density ranged between 0.838 ± 0.33 and 4.01 ± 0.55 items/m2 in the beach stations, and 0.93 ± 0.27 2.40 ± 2.18 items/m2 in the streamside stations. No significant difference was determined among the seasons for both beach and streamside (Kruskal-Wallis test, p > 0.05). On the other hand, the litter density was also similar in beach and streamside stations in the same season. The litter composition consisted of > 75% plastic. Principal component analysis and PERMANOVA determined no significant difference in litter composition among beach and streamside stations. The litter items mostly consisted of single-use items. Among them, plastic beverage containers were the most abundant litter subcategory during the study (ranging between 18.79% and 34.50%). The subcategory composition exhibited a significant difference among beach and streamside stations (ANOSIM, p < 0.05), which was mainly explained by plastic pieces, beverage containers, and foams according to SIMPER analysis. Personal protection equipment that was not reported before the COVID-19 pandemic emerged. The results of our study can be used for marine litter modeling studies and legislation for restriction or ban of most abundant single-use litter items.

Spatio-temporal variability in the abundance and composition of beach litter and microplastics along the Baltic Sea coast of Schleswig-Holstein, Germany.

Abundance and composition of beach litter and microplastics (20-5000 µm, excluding fibres) were assessed in spring and autumn 2018 at various beaches along the Baltic Sea coast of Schleswig-Holstein, Northern Germany. The beach litter survey followed the OSPAR guidelines, while microplastics were extracted from sediment samples using density separation and were then identified with Raman µ-spectroscopy. We observed seasonality in the abundance and composition, but not in the mass of beach litter. The median microplastic abundance was 2 particles per 500 g of dry sediment in spring as well as in autumn, while six different synthetic polymers (PE, PP, PS, PET, PVC, POM) were detected. We found no correlation between the abundances of beach litter and microplastics. Our data represent the first systematic co-assessment of macro- and micro beach litter along the Baltic Sea coast of Schleswig-Holstein.

Difference between invasive alien and native vegetation in trapping beach litter: A focus on a typical sandy beach of W-Mediterranean Basin.

Beach litter is one of the most pervasive pollution issues in coastal environments worldwide. In this study, we aim to assess the amount and distribution of beach litter on Porto Paglia beach, its entrapment across psammophilous habitats, and whether the invasive Carpobrotus acinaciformis (L.) L.Bolus plays a different role in trapping litter than native vegetation. To this end, two seasonal samplings (in spring and autumn) were conducted using a paired sampling method that considers plots in all coastal habitats with and without C. acinaciformis. Our results confirm that the main beach litter category is plastic, and that its distribution varies across habitats: the white dune seems to play a greater role in trapping and filtering beach litter, reducing its amount in the backdune. A correlation was found between the Naturalness index (N) and the beach litter amount, supporting the finding that invaded habitats trap beach litter better than native ones.

Setting thresholds is not enough: Beach litter as indicator of poor environmental status in the southern Adriatic Sea.

This study deals with the issue of beach litter pollution in the context of the Descriptor 10 of the Marine Strategy Framework Directive Good Environmental Status of EU waters and Ecological objective 10, Common indicator 22 of IMAP. Analyses of the amount, distribution and categorization of beach litter were conducted on nine beaches during 108 surveys covering the area of 206.620 m2 in Albania, Italy and Montenegro. Our findings showed that the level of beach litter pollution on south Adriatic beaches is significantly above the adopted threshold values, with a median item numbers of 327, 258 and 234 per 100 m of beach stretch for Albania, Italy and Montenegro, respectively. It can be concluded that, when it comes to beach litter pollution, GES has not been achieved. Given the defined baseline and threshold values at the EU level, the process of reducing the total amount of marine litter in southern Adriatic Sea will be very challenging and needs urgent and specific actions.

Abundance, composition and sources of beach litter on the Cape Verdean island São Vicente.

This study represents the first assessment of beach litter on an island of the west African archipelagic state of Cape Verde. On five beaches of São Vicente, litter was collected along transects and classified according to the OSPAR protocol, with the Matrix Scoring Technique used to allocate it to four sources. Beach litter on São Vicente is highly variable in both amount and composition, while land- and sea-based sources contribute to litter loads to different extents depending on the use and geographic orientation of the beach. Four of the five surveyed beaches exhibited litter loads that were similar to pollution levels previously described for other oceanic islands, while a north-eastern-facing beach featured exceptionally high loads. This was presumably because it receives litter from distant sources due to its exposure to a major ocean surface current.

Beach litter contamination of the Turkish middle Black Sea coasts: Spatial and temporal variation, composition, and possible sources.

Marine litter is one of the biggest environmental problems nowadays. Sinop, is located in the heart of Türkiye's Black Sea coast, has a small population, and is a popular fishing and tourist destination. In this study, marine litter amount, composition, and possible sources were investigated, and seasonal comparisons were made between in Sinop beaches. Marine litter amount was found as 0.29-7.67 items·m-2 and 3.46-49.09 g·m-2 and beaches were classified as moderate to extremely dirty. Plastics were the highest ratio (88.14-98.46 %) and "plastic pieces 2.5> <50 cm" were the major litter type. The major possible litter source was improper waste disposal (33.36 %) and litter items originated from mainly land-based sources (74.13 %). The result of this study shows that there is a significant litter problem on the coasts. The solution of this problem can be possible to take rational measures against marine litter pollution with education and management policies.

Different faces of cigarette butts, the most abundant beach litter worldwide.

Cigarette butts (CBs) are non-biodegradable residues of synthetic origin, prevalent on beaches all over the world. The study evaluates discarded CBs on an intensely used urban beach, determining variations in physical and chemical characteristics. CBs collected were observed, classified, and visually separated according to a proposed scale of four levels of degradation to test the potential match between physical and chemical decay. CBs (un-smoked, smoked, and discarded) were used to determine the average length (cm) and mass (g) in order to observe changes in these parameters among the levels. Cigarette butts experience consecutive mass loss during environmental exposure. Scanning electron microscopy (SEM) images were obtained to assess physical changes in fibers due to smoking. FTIR-ATR was used to assess CBs new (un-smoked), smoked, and discarded samples in relation to cellulose acetate decay. The FTIR-ATR spectroscopy of the most visually degraded cigarette butts indicated modifications in the spectra when compared to un-smoked cigarettes.

Pixel-level image classification for detecting beach litter using a deep learning approach.

Mitigating and preventing beach litter from entering the ocean is urgently required. Monitoring beach litter solely through human effort is cumbersome, with respect to both time and cost. To address this problem, an artificial intelligence technique that can automatically identify different-sized beach litter is proposed. The technique was established by training a deep learning model that enables pixel-wise classification (semantic segmentation) using beach images taken by an observer on the beach. Eight segmentation classes that include two beach litter classes were defined, and the results were qualitatively and quantitatively verified. Segmentation performance was adequately high based on three metrics: Intersection over Union (IoU), precision, and recall, although there is room for further improvement. The potency of the method was demonstrated when it was applied to images taken in different places from training data images, and the coverage of artificial litter calculated and discussed using drone images provided ground truth.

Characterization of foamed plastic litter on Danish reference beaches - Pollution assessment and multivariate exploratory analysis.

Foamed litter comprise a significant amount of the pollution at beaches globally. This group represents a variety of foamed items and fragments originating from different applications and sources. Although foamed plastic contributes importantly to the marine environmental pollution, there is generally limited knowledge of the composition of this litter pool. The aim of this study was to characterize item types and polymer materials of foamed litter from six Danish reference beaches during the period 2018-2021. The foamed litter were classified into ten categories, including identifiable items, as well as fragments of foamed PS, or pieces of other foamed polymers of rigid or flexible sponges. Foamed PS (42%) and PUR (49%) were identified as the dominant polymers by FTIR analysis. Multivariate exploratory analysis was performed to investigate PUR foam, and specific spectra features for rigid and flexible foam were demonstrated. Furthermore, we assessed different correlation methods for identification of PUR foams.