Anthropogenic Litter on Beaches With Different Levels of Development and Use: A Snapshot of a Coast in Pernambuco (Brazil)

A review of plastic debris in the South American Atlantic Ocean coast - Distribution, characteristics, policies and legal aspects

The presence of plastics in the oceans has already become a pervasive phenomenon. Marine pollution by plastics surpasses the status of an emerging threat to become a well-established environmental problem, boosting research on this topic. However, despite many studies on the main seas and oceans, it is necessary to compile information on the South American Atlantic Ocean Coast to identify the lack of research and expand knowledge on marine plastic pollution in this region. Accordingly, this paper conducted an in-depth review of monitoring methods, sampling, and identification of macroplastics and microplastics (MPs) in water, sediments, and biota, including information on legal requirements from different countries as well as non-governmental initiatives. Brazil was the country with the highest number of published papers, followed by Argentina. MPs accounted for 75 % of the papers selected, with blue microfibers being the most common morphology, whereas PE and PP were the most abundant polymers. Also, a lack of standardization in the methodologies used was identified; however, the sites with the highest concentrations of MPs were the Bahía Blanca Estuary (Argentina), Guanabara Bay (Brazil), and Todos os Santos Bay (Brazil), regardless of the method applied. Regarding legislation, Uruguay and Argentina have the most advanced policies in the region against marine plastic pollution due to their emphasis on the life cycle and the national ban on certain single-use plastics. Therefore, considering its content, this expert review can be useful to assist researchers dealing with plastic pollution along the South American Atlantic Ocean Coast.

Application of improved machine learning in large-scale investigation of plastic waste distribution in tourism Intensive artificial coastlines

Oceans are ultimately a sink of plastic waste. Complex artificial coastlines pose remarkable challenges for coastal plastic waste monitoring. With the development of machine learning methods, high detection accuracy can be achieved; however, many false positives have been noted in various network models used for plastic waste investigation. In this study, extensive surveys of artificial coastlines were conducted using drones along the Dongjiang Port artificial coastline in the Binhai District, Tianjin, China. The deep learning model YOLOv8 was enhanced by integrating the InceptionNeXt and LSK modules into the network to improve its detection accuracy for plastic waste and reduce instances of tourists being misidentified as plastic. In total, 553 high-resolution coastline images with 3488 items of detected plastic waste were compared using the original and improved YOLOv8 models. The improved YOLOv8s-IL model achieved a detection rate of 64.9%, a notable increase of 11.5% compared with that of the original model. The number of false positives in the improved YOLOv8s-IL model was reduced to 32.3%, the multi-class F-score reached 76.5%, and the average detection time per image was only 2.7 s. The findings of this study provide technical support for future large-scale monitoring of plastic waste on artificial coastlines.

Citizen scientists study beach litter along 12,000 km of the East Pacific coast: A baseline for the International Plastic Treaty

Anthropogenic Marine Litter (AML) accumulating on beaches causes damage to coastal ecosystems and high costs to local communities. Volunteers sampled AML on 130 beaches along the central and southern East Pacific coasts, with AML densities ranging from 0.46 to 2.26 items m-2 in the different countries. AML composition was dominated by plastics and cigarette butts, the latter especially in Mexico and Chile. The accumulation of AML in the upper zones of the beaches and substantial proportions of cigarette butts, glass and metal pointed mainly to local sources. Statistical modelling of litter sources on continental beaches revealed that tourism, access and related infrastructure (e.g. parking lots) best explained AML densities, while plastic densities were also influenced by the distance from river mouths and national Gross Domestic Product. Large-scale monitoring can be a useful tool to evaluate the effectiveness of public policies that should primarily focus on land sources.

Marine litter in the Red Sea: Status and policy implications

The Red Sea's unique ecosystem is home to >1500 species. However, the presence of anthropogenic litter, whether from land-based or sea-based sources, may pose a potential risk to the Red Sea fauna and flora. This work analyzes marine litter in the Red Sea, utilizing the Drivers-Pressure-State-Impact-Response (DPSIR) framework to group findings in a survey of peer-reviewed studies. The review is further augmented with a survey of the current response, covering regional and national instruments. Although research addressing marine litter in the Red Sea is not as rich as for other seas, studies suggest marine litter is abundant and that the influx of litter is driven by recreational activity, fishing, and shipping. Moreover, the COVID-19 pandemic has exacerbated the influx of marine litter to the Red Sea due to improper disposal of personal protective equipment (PPE). The response has intensified in recent years, with regional and national frameworks established and initiatives driven by Non-Governmental Organizations (NGOs). We discuss whether the regional action plan addresses the specific concerns uncovered in marine litter studies while providing a comparison with plans of other regional seas.

Understanding through drone image analysis the interactions between geomorphology, vegetation and marine debris along a sandy spit

Marine litter (ML) is recognized as one of the main socio-economic and environmental concerns and monitoring operations have been realized worldwide in order to collect information on the types, quantities and distribution of marine debris. In this study, we used Unmanned Aerial Vehicle (UAV) images to map the presence of ML on a coastal spit in relation to geomorphological aspects and vegetation. Our results show that ML is present everywhere, but concentrates in the beach wrack, dunes, and saltmarshes, highlighting the role of the vegetation in trapping ML. Moreover, ML will most probably remain trapped by the saltmarsh vegetation, since they are not visible and easily accessible to allow cleaning operations. On the contrary, cleaning operations may remove the ML present in the beach wrack. Finally, our results provide useful information to support decision-makers for improving beach cleaning activities in the Po river Delta areas (Italy).

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.

Relationships between marine litter and type of coastal area, in Northeast Atlantic sandy beaches

Marine litter represents a threat to the marine environment, being estimated that around eight million items are discarded daily in the ocean. Monitoring marine debris became a relevant topic of research as marine litter is one of the descriptors of the Marine Strategy Framework Directive, for European Union's member states. Nevertheless, the patterns and processes governing the disposal of waste in coastal areas are still not clear. Our study relates characteristics of eleven coastal areas in Portugal (urbanization, slope, distance to an estuary, length, and type of substrate) to the type and abundance of marine litter found. A total of 7743 items were identified, with the main types of litter found being plastic (71.2%), paper (16.3%), and sanitary waste (9.1%). A clear spatial distribution pattern was observed, with more litter items recorded in the zone corresponding to the high tide line (2.3 items m^-2). It was also verified that both beaches and seasons influenced the amount of litter found. Plastic, the dominant marine litter group, was abundant on the vast majority of beaches. It was possible to identify litter with land and sea origins. The litter with land origin came mainly from sanitary and sewage-related waste while the litter with marine origin came mainly from fisheries, including aquaculture.

Impacts of the COVID-19 pandemic restrictions on solid waste pollution in the worldwide iconic Copacabana Beach (Rio de Janeiro, Brazil)

Total and partial restrictions to beach access during COVID-19 pandemic created an opportunity to evaluate its effect on coastal pollution. We aimed to determine the impact of access restrictions on solid waste pollution at Copacabana beach, Brazil. Solid waste amount was analyzed considering beach access restrictions: unrestricted, total closure, partial restriction, new normal. Relationships of atmospheric temperature and precipitation with access restrictions were assessed and confounding effects controlled for further analyses. Beach access restrictions significantly reduced solid waste pollution at Copacabana beach, beach closure reduced waste amount in 72 %. Partial restrictions and new normal periods have significantly reduced solid wastes amount on the beach in 60 % and 36.88 %, respectively. Qualitative data revealed that most of solid wastes were single-use plastics recently disposed at Copacabana beach, reflecting beachgoer's effects on waste left on the beach. A positive impact of COVID-19 pandemic restrictions was detected on solid waste pollution at Copacabana beach.

On the indirect environmental outcomes of COVID-19: short-term revival with futuristic long-term implications

The aim of this study is to identify and highlight the positive and negative indirect environmental impacts of COVID-19, with a particular focus on the most affected economies (USA, China, Spain, and Italy). In this respect, the empirical and theoretical dimensions of the contents of those impacts are analyzed. Research findings reveal a significant relationship between contingency actions and positive indirect impacts such as air quality improvements, clean beaches, and the decline in environmental noise. Besides, negative indirect impacts also exist, such as the rise in waste level and curtailment in recycling, further threatening the physical spaces (land and water), besides air. It is expected that global businesses will revive in the near future (though slowly), but the reduction in greenhouse gas emissions during this short time span is not a sustainable way of environmental mitigation. Thus, long-term mitigation policies should be strengthened to cope with the undesirable deterioration of the environment. Research findings provide an up-to-date glimpse of the pandemic from the perspectives of current and future indirect environmental impacts and the post-pandemic situation. Finally, it is suggested to invent and prepare action plans to induce a sustainable economic and environmental future in the post-pandemic world scenario.

Contrasting tourism regimes due to the COVID-19 lockdown reveal varied genomic toxicity in a tropical beach in the Southern Atlantic

Tourist occupancy in coastal environments threatens the stability of various coastal ecosystems and is thus a cause for concern for the environmental sector. As such, it is important to perform environmental monitoring in a way that analyses and quantifies the environmental impact of coastal ecosystems. Porto de Galinhas beach (Pernambuco - Brazil) has one of the highest visitation rates in Brazil and suffered from restrictions to human mobility due to the COVID-19 pandemic. These restrictions allowed for the evaluation of the impact of tourism on Porto de Galinhas beach and the effects that the lack of tourist occupancy had during the lockdown period of 2020. Blood samples from the species Abudefduf saxatilis were collected monthly over a period of 1 year and during the lockdown quarter, in order to perform micronucleus (MN) and nuclear morphological alteration (NMA) tests, and data were analyzed at a seasonal level (dry/rainy period) using a comet assay. For the control group, A. saxatilis samples were collected in an environmentally protected area on Tamandaré beach (68 km from Porto de Galinhas). The MN and NMA tests showed a greater frequency of genomic damage when there was greater tourist flow. In relation to rain seasonality, the comet assay showed a greater incidence of genomic damage during the dry period, where there was a higher rate of tourist migration, compared to the rainy period. The lockdown period presented a lower incidence of genotoxic damage compared to the period without restrictions on human mobility and the control. The results show that tourism has been causing a significant environmental impact on Porto de Galinhas beach. The data collected during the lockdown period demonstrated how the absence of human movement results in changes that are favorable to environmental recuperation, as illustrated by the lower frequency of genomic damage.

Beach debris quantity and composition around the world: A bibliometric and systematic review

Anthropogenic pollution of marine ecosystems caused by beach debris has become a serious environmental concern in the last few decades. Regarding the raising production of beach debris, the present work aimed to summarize the quantity and quality of beach debris reported from different beach areas of the world. Also, a bibliometric analysis was used to analyze research trends and upgrade knowledge in this research area. Using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), the eligible papers reviewed regarding beach debris abundance along with their composition from 2010, which were extracted from the Scopus database. The results of the study showed that plastic items represented the dominant material (61.25%), followed by food (5.88%), wood (5.78%), metals (5.2%), and glass (5%). Further, the beaches studied were classified into three degrees, including highly polluted (31.5 items/m2), moderate polluted (3.47 items/m2), and low polluted (0.37 items/m2), based on the average abundance of debris.

Are Tourists Willing to Pay for a Marine Litter-Free Coastal Attraction to Achieve Tourism Sustainability? Case Study of Libong Island, Thailand

Coastal areas around the world are under increasing environmental pressures from marine litter. In particular, tourism in coastal tourist areas suffers with waste littering on the coast, as well as in the water. Therefore, substantial costs are required for the handling of marine litter in order to achieve sustainable development in the tourism sector. The introduction of an entrance fee as an economic tool is a feasible way to provide alternative financing, in addition to limited government funding. The objective of this study was to estimate tourists’ willingness to pay (WTP) for visiting a marine litter-free coastal attraction, and examine the factors affecting the WTP. A questionnaire was employed using a single-bound dichotomous choice method on Libong Island, Thailand, between September and December 2020. A logistic model was used to estimate the WTP of the 1655 respondents. The mean WTP obtained is THB 92.24 per person per visit (approximately USD 3). The expected benefit of charging an entrance fee is THB 27.52 million (USD 0.88 million) for 2019. The factors influencing WTP are bid amount, age, education, monthly income, marine litter perception, and environmentally responsible behaviors. Associated initiatives were recommended to achieve coastal destination sustainability, including regular clean-up operations at beaches, seagrass beds, and surrounding waters; the placement and maintenance of litter facilities; and the promotion of marine litter awareness and environmentally responsible behaviors.

Disentangling beach litter pollution patterns to provide better guidelines for decision-making in coastal management

Beach litter represents a worldwide problem impacting both terrestrial and aquatic environments. In the present study, we assessed beach litter pollution in a prominent touristic site in Brazil, the Jericoacoara National Park. In particular, we applied a delta-generalized additive modeling (GAM) approach in order to investigate pollution hotspots and to provide better guidelines for coastal environmental managers. A total of 7549 litter items were collected, resulting hard and flexible plastics the most abundant type. Our GAM analysis revealed that the distribution of each type of litter was affected by distinct drivers in the protected area, with the extension of the beach, tourist attractions, wind angle, and the distance to water bodies and villages as the most significant explanatory variables. Our model is suitable in predicting litter pollution hotspots on beaches, which is a valuable tool for future guidelines and effective management strategies to prevent beach pollution worldwide.

Scientific knowledge on marine beach litter: A bibliometric analysis

Litter reduction in the coastal and marine environment represents a major challenge but must be prioritized to preserve biodiversity and ecosystems, as well as the goods and services that humans derive from seas and oceans. This paper reviews the available global scientific literature focusing on marine beach litter and tracks its evolution and trends by combining social network analysis and bibliometrics. The relationships and co-occurrences among authors, countries and keywords retrieved from the Scopus abstract and citation database are presented. A total of 1765 publications are analysed: the majority being journal articles. Results reveal the notable worldwide increase in scientific interest in beach litter in the last decade, as well as its multidisciplinary perspectives. This information could be beneficial for the processes that support the improvement of international efforts for beach litter monitoring, removal, and management activities.

Daily environmental variation influences temporal patterns of marine debris deposition along an estuarine outlet in southern Brazil

The influence of short-term (daily) variation in environmental conditions (rainfall, wind, tide, river flow) on debris accumulation was examined on two beaches at an estuarine outlet. Sampling occurred over 60 consecutive days along two sections (Internal Area, IA; and External Area, EA) of the Paranaguá Estuary Complex's southern outlet, in Paraná, southern Brazil. The IA is sheltered from direct wave action, whereas the EA is more exposed to wave and wind action from the open ocean. The IA accounted for 71% of the total debris, while the EA accounted for 29%. Debris abundance was highest after intermediate bouts of rainfall, although river flow only affected debris accumulation in the IA. Wind and tide influenced accumulation differently across sites. These results highlight the importance of short-term variation in the accumulation of marine debris on sandy beaches, which should be considered when designing and monitoring assessment programs and removal strategies.

Plastic litter pollution along sandy beaches in Puerto Princesa, Palawan Island, Philippines

Marine plastic litter pollution has become an emerging threat to the Philippines, especially in Palawan. This study was conducted to investigate the macroplastic litter and determine the clean-coast index (CCI) of the residential and non-residential sites on the coasts of Puerto Princesa, Palawan. Plastic litters were sampled from 21 coastal barangays by delineating a 50-m-long transect line with three 4 m × 4 m quadrats. The litter sampled were counted and sorted into categories. The results showed that 17 sites were contaminated with plastic litters. In terms of residential and non-residential sites, the east coast has thrice as much plastic, 2.61 items/m² and 1.26 items/m² compared to west coast with only 1.57 items/m² and 0.14 items/m², respectively. The plastics sampled were predominantly fishing line (nylon), food packaging, and fragments. The calculated CCI revealed that 76% of the sites sampled were categorized as dirty and extremely dirty.

Occurrence, characterization, partition, and toxicity of cigarette butts in a highly urbanized coastal area

Cigarette butts (CBs) comprise one of the most relevant categories of marine litter worldwide. This study was structured as a case study simultaneously assessing (i) the occurrence of CBs in a highly urbanized coastal area, (ii) their partitioning in two environmental compartments (water column and sediments) by laboratory settling tests, and (iii) the toxicity produced by the CBs leachates (measured as copepod reproduction). Marine litter was sampled in beaches of the city of Santos (SW Brazil) and CBs were collected for analysis. The characterization showed that CBs were one of the most prevalent items (51.5% in summer and 34.4% in winter) and 22 cigarettes brands were identified at different stages of decomposition. Laboratory settling tests showed that CBs remain in the water column between 3 and 20 days, subsequently reaching the sediments. The toxicity results indicated that CBs the leachates extracted from a small amount of CBs was sufficient to affect copepod reproduction (0.1 and 0.01 CBs L^-1). Furthermore, the approaches adopted by the present study can serve as a preliminary assessment to estimate local impacts resulting from inadequate disposal of cigarette butts in coastal areas around the world.

Spatio-temporal characterization of litter at a touristic sandy beach in South Brazil

Litter is an ecological, economic, and social problem that impacts marine environments around the world. To create prevention and mitigation measures to solve this issue, it is necessary to understand the amounts and sources of this type of pollution. Cassino Beach is an extensive sandy beach located in South Brazil (∼220 km in length) that presents multiple uses, such as touristic, portuary and fishery activities. In order to evaluate the spatial and seasonal variation of litter amounts, types and sources at Cassino Beach, litter (>2.5 cm) was collected over 27 months at two urban and two non-urban sites. At each site, the litter present in three 200 m² areas was sampled and evaluated. A total of 19,457 items were collected, mostly composed by plastic (∼88%). Paper, metal, and cloth items were also present, but in low amounts. Fragments and cigarette butts were the major types of plastic litter, with abundances of 28.4% and 17.0%, respectively. Urban sites presented higher amounts of litter, with those related to beach use being more common, emphasizing the contribution of beachgoers to litter input at these sites. During the summer season, when beach use increases, the highest total litter concentration was found. Undefined and/or beach use-related sources were dominant in all sites and seasons. Mapping the predominant materials, types and potential sources of litter creates important baseline data that can contribute not only to beach monitoring, but also to the development of litter reduction strategies.

How does the beach ecosystem change without tourists during COVID-19 lockdown?

Urban tourist beach ecosystems provide the essential service of recreation. These ecosystems also support critical ecological functions where biodiversity conservation is not usually a priority. The sudden lockdown due to the COVID-19 pandemic created a unique opportunity to evaluate the effects of human absence in these urban-coastal ecosystems. This study examined bioindicators from 29 urban tourist beaches in seven Latin-American countries and assesses their response to lockdown about some relevant anthropogenic stressors such as pollution, noise, human activities, and user density. The presence of animals and plants, as well as the intensity of stressors, were assessed through a standardized protocol during lockdown conditions. Additionally, the environmental conditions of the beaches before and during lockdown were qualitatively compared using multivariate non-parametric statistics. We found notable positive changes in biological components and a clear decrease in human stressors on almost all the beaches. Dune vegetation increased on most sites. Similarly, high burrow densities of ghost crabs were observed on beaches, except those where cleaning activity persisted. Because of the lockdown, there was an exceptionally low frequency of beach users, which in turn reduced litter, noise and unnatural odors. The observed patterns suggest that tourist beaches can be restored to natural settings relatively quickly. We propose several indicators to measure changes in beaches once lockdown is relaxed. Adequate conservation strategies will render the recreational service of tourist beaches more environmental-friendly.

Marine litter on a highly urbanized beach at Southeast Brazil: A contribution to the development of litter monitoring programs

Seasonal distribution of Marine Litter (ML) on Santos beaches was assessed using a citizen science strategy. Plastics and cigarette butts (CB) were the dominant items in all sampling campaigns. Seasonal distribution did not result in significant differences for most items. Plastic and CB amounts were high in summer compared to autumn. For all sampled sites the presence of beach users influenced ML densities. However, results showed that some sites presented an additional influence of local hydrodynamic. Moderate amounts of hazardous items including metal, glass, CB, sanitary waste and plastic tubes used to pack and market illicit drugs represented between 20.8 and 31% of all ML over the seasons. The beaches of Santos were classified as dirty in autumn and spring and as extremely dirty in winter and summer. These findings can serve as a baseline to support mitigating actions by public authorities and start monitoring programs of ML not only in Santos but also in other urbanized beaches.

Mapping marine litter on coastal dunes with unmanned aerial systems: A showcase on the Atlantic Coast

Marine litter pollution on coastal dunes has received limited scientific attention when compared with sandy shores. This paper proposes a new framework based on the combined use of Unmanned Aerial Systems (UAS) and a mobile application to map and quantify marine macro-litter (>2.5 cm) accumulation on coastal dunes. The first application on a dune area of 200 m × 80 m at the north-east Atlantic Portuguese coast is shown. Nine different marine litter categories were found, with styrofoam fragments (23% of the total amount) and plastic bottles (20%) being the most abundant items. Plastic was the most common material (76%). The highest number of items (272) was found on the backdune, mostly related with fishing activities (octopus pots and Styrofoam fragments). In contrast, the highest density (0.031 items/m²) was found on the foredune, with the most abundant items associated with human recreational activities (for example, plastic bottles, bags, papers and napkins). Three major marine litter hotspots (~0.1 items/m²) were identified in correspondence of dune blowouts. The recognition of the primary marine litter pathways highlighted the main role that wind and overwash events play on dune contamination, and suggests that the dune ridge restoration can act as a mitigation measure for preventing marine litter accumulation on the backdune. This study shows how UAS offer the possibility of a detailed non-intrusive survey, and gives a new impulse to coastal dune litter monitoring, where the long residence time of marine debris may threaten the bio-ecological equilibrium of these ecosystems.

An open-source geospatial framework for beach litter monitoring

Here, we present a framework for a beach litter monitoring process, based on free and open-source software (FOSS), which allows customization for any sampling design. The framework was developed by means of a GIS project (QGIS), a GIS collector (QField), and an R code, allowing further adjustments according to the area to be surveyed and research questions. The aim is to improve data collection, accessibility, and interoperability, as well as to help to fill the currently existing gap between fieldwork and data analysis, preventing typos and allowing better data processing. Therefore, it is expected to take less than an hour from ending fieldwork to obtaining up-to-date products. To test the developed open-source geospatial framework, it was applied in different sectors and dates on an important southern Brazilian touristic beach. Results obtained from the open-source geospatial framework application produce baseline information on beach litter issues, such as amounts, sources, and spatial and temporal patterns. Adoption of the framework can facilitate data collection by local and regional stakeholders, and the results obtained from it can be applied to support management strategies. For researchers, it produces spatialized data for each item in an already tidy format, which can be used for robust and complex models. A series of supplementary files support reproducibility and provide a guide to future users.

Cigarette butts on Baltic Sea beaches: Monitoring, pollution and mitigation measures

OSPAR, Rake and Flood accumulation zone methods were applied at 29 beaches of the German and Lithuanian Baltic Sea coast (2011-2018) to monitor cigarette butt pollution. Also, butt pollution prevention measure - ballot bin, was tested. The number of cigarette butts was significantly higher in Germany than in Lithuania, but the percent of butts from total litter items was similar. Rake method turned out to be suitable for cigarette butt assessment, while the OSPAR method underestimates the butt pollution. The visitor number on the beach had a significant effect on the cigarette butt number: in remote beaches, without visitors, usually, no butts were observed, while the highest number and the percent of butts were observed in beaches with the highest number of visitors. The ballot bin campaign may have increased the public awareness about pollution, but turned out to be in-efficient in reducing it.

Mapping marine litter with Unmanned Aerial Systems: A showcase comparison among manual image screening and machine learning techniques

Recent works have shown the feasibility of Unmanned Aerial Systems (UAS) for monitoring marine pollution. We provide a comparison among techniques to detect and map marine litter objects on an UAS-derived orthophoto of a sandy beach-dune system. Manual image screening technique allowed a detailed description of marine litter categories. Random forest classifier returned the best-automated detection rate (F-score 70%), while convolutional neural network performed slightly worse (F-score 60%) due to a higher number of false positive detections. We show that automatic methods allow faster and more frequent surveys, while still providing a reliable density map of the marine litter load. Image manual screening should be preferred when the characterization of marine litter type and material is required. Our analysis suggests that the use of UAS-derived orthophoto is appropriate to obtain a detailed geolocation of marine litter items, requires much less human effort and allows a wider area coverage.

Status of the Beach Litter in the UNESCO World Heritage Site of Dungonab and Mukkawar Island Marine National Park in Sudan, Red Sea

Information on marine litter in general and beach litter in particular from Sudan and to some extent from the Red Sea region is insufficient. The aim of this study is to assess the beach litter composition, distribution, and abundance in some selected beaches of the World Heritage Site of Dungonab Bay and Mukkawar Island National Park (DMNP) located in Sudan, Red Sea coast, and to examine the rate of beach litter flux and the cleanliness of its beaches in order to provide baseline information for beach litter management at DMNP. A total of 6 sites were investigated for beach litter over a 10-month period from January to October 2017 on a quarterly basis. A total of 24 collections of beach litter were performed covering a stretch of 600 m or 7700 m2 of DMNP coastline. In total, 3037 beach litter items were collected during the study time from DMNP with an overall average of 506.2 ± 409.8 items/100 m (0.4 items/m2). Plastic beach litter was the most abundant (1738 items), constituting 57.23% with an average density of 289.7 ± 242.2 items/100 m (0.23 items/m2). The beaches of DMNP were clean (CCI = 4.6) at the time of the study. The rate of flux of the beach litter decreased steadily from 21.9 to 16.43 items/100 m/day with an overall average of 18.82 ± 2.8 items/100 m/day. The gradual decrease in the net accumulation of beach litter over the period of the study suggests that the beach litter at DMNP was likely of a local land-based origin and the beaches of DMNP are not a potential sink of marine litter. The determination of the rate of flux of beach litter is a reasonable indicator of the dynamics of beach litter in DMNP. Accordingly, application of preventive measures accompanied with awareness activities and investment in plastic collection and recycling would further enhance and preserve the present status of beach cleanliness and encourage tourism activities.

Marine plastic litter in the ROPME Sea Area: Current knowledge and recommendations

The impact of marine litter, particularly plastic waste, is widely acknowledged as a growing global concern. Marine litter is an understudied issue in the Regional Organisation for Protection of the Marine Environment (ROPME) Sea Area where rapid economic growth has already placed considerable stress on infrastructure and coastal ecosystems. This paper outlines some of the drivers for waste generation in region and reviews the available literature to summarise the current state of knowledge on the environmental fate, behaviour and impact of marine litter within the ROPME Sea Area. While data is limited, those studies conducted demonstrate marine litter is posing a clear and growing threat to the environmental and socioeconomic prosperity of the ROPME Sea Area. The development of regional and national marine litter reduction plans are clearly a priority to focus and coordinate activity across multiple stakeholders. Discussion of the potential environmental impacts arising as a result of marine litter are presented together with a roadmap for establishing and implementing a ROPME Sea Area Marine Litter and Single-Use Plastic Action Plan.

Collection of Anthropogenic Litter from the Shores of Lake Malawi: Characterization of Plastic Debris and the Implications of Public Involvement in the African Great Lakes

Anthropogenic debris is an environmental problem that affects beaches and coastlines worldwide. The abundance of beach debris is often documented with the use of public volunteers. To date, such community participations have been largely confined to the marine environment, but the presence and impact of anthropogenic debris on freshwater shorelines has been increasingly recognized. Our study presents the first such information from the African Great Lakes, specifically Lake Malawi. A total of 490,064 items of anthropogenic litter were collected by over 2000 volunteers in a clean-up campaign that took place annually between 2015 and 2018. Approximately 80% of the anthropogenic debris was comprised of plastic litter, with plastic carrier bags being the most common item. The dominance of plastic litter, and in particular the presence of plastic bags, which have subjected to bans in some African countries, is discussed. The broader implications of citizen science in the African Great Lakes area is also discussed.