Plastic Debris Research Articles

Unravelling the Nexus of Beach Litter and Plant Species and Communities Along the Mediterranean Coasts: A Critical Literature Review

Beach litter, an anthropogenic and hazardous component, can interact with psammophilous plant species and communities. These are particularly prominent in the Mediterranean Basin, renowned for its highly specialized and unique flora but recognized as one of the areas that is globally most severely affected by marine litter. To provide a comprehensive picture and outline possible future directions, data on beach litter in the Mediterranean coastal ecosystems were collected through a bibliographic research. Overall, 103 studies investigated the presence of beach litter on the Mediterranean coasts, of which only 18 considered its relationship with psammophilous plant species and communities. Our research highlights that this topic is rather underexplored in the Mediterranean Basin and the need to develop a standardized protocol for the assessment of beach litter that can be applied consistently across different beaches and countries. Information collected through a standardized protocol might improve the management and conservation strategies for these fragile ecosystems.

Acoustic Imaging Learning-Based Approaches for Marine Litter Detection and Classification

This paper introduces an advanced acoustic imaging system leveraging multibeam water column data at various frequencies to detect and classify marine litter. This study encompasses (i) the acquisition of test tank data for diverse types of marine litter at multiple acoustic frequencies; (ii) the creation of a comprehensive acoustic image dataset with meticulous labelling and formatting; (iii) the implementation of sophisticated classification algorithms, namely support vector machine (SVM) and convolutional neural network (CNN), alongside cutting-edge detection algorithms based on transfer learning, including single-shot multibox detector (SSD) and You Only Look once (YOLO), specifically YOLOv8. The findings reveal discrimination between different classes of marine litter across the implemented algorithms for both detection and classification. Furthermore, cross-frequency studies were conducted to assess model generalisation, evaluating the performance of models trained on one acoustic frequency when tested with acoustic images based on different frequencies. This approach underscores the potential of multibeam data in the detection and classification of marine litter in the water column, paving the way for developing novel research methods in real-life environments.

Community composition and seasonal dynamics of microplastic biota in the Eastern Mediterranean Sea

Marine plastic pollution poses a growing environmental threat, with microplastics accumulating in the global oceans. This study profiles the seasonal dynamics and taxonomic composition of the plastisphere, the microplastic ecosystem, in the Eastern Mediterranean Sea. Using long-read 16 S and 18 S metabarcoding, we analyzed offshore microplastic and whole seawater samples across each season over a two-year period. The analysis revealed a higher richness of prokaryotic communities on microplastics compared to seawater, which was predominantly composed of Proteobacteria and Bacteroidota and exhibited notable seasonal variability. Benthic eukaryotes were enriched on microplastics compared to the surrounding seawater. Diatoms (Bacillariophyceae), in particular, showed significant enrichment within the microplastic eukaryotic community with primarily pennate diatoms of Amphora, Navicula, and Nitzschia genera, whereas the seawater included mostly centric diatoms. Seasonal fluctuations were less pronounced in the microplastic communities than in seawater, highlighting the relative stability of this new human-made ecosystem. These findings underscore the unique ecological niche of microplastic-associated communities in marine environments.

Establishing a plastic waste map using remote sensing data in the coastal area of Thanh Hoa province (Vietnam)

Plastic pollution, particularly in oceans, is a growing environmental threat. Monitoring this pollution is challenging due to the shortage of data and tools. Remote sensing offers a promising solution by using various types of satellite and aerial images to detect and track plastic waste movement. Purpose. The study aims to establish a plastic waste map using remote sensing technology, focusing on the case study of the coastal area of Thanh Hoa province, Vietnam. Methodology. The study involves several steps, including the collection of plastic waste data (samples in the case study and indices from remote sensing images) as well as topographic and base map collection, statistics of plastic samples, grid design, calculation, interpolation, accuracy assessment, and mapping. Field surveys involved taking pictures of plastic debris along designated routes and a grid system was used to classify and calculate waste samples. Satellite images, especially Sentinel-2 MSI optical satellite imagery, are utilized to identify water areas of high plastic concentration. Findings. A map of plastic wastes in coastal areas of Thanh Hoa was created, with indices like NDWI (Normalized Difference Water Index) and FDI (Floating Debris Index) helping identify potential plastic waste signals. The resulting map reveals high concentrations of plastic waste in sea areas near the major river mouths of the Ma River basin and tourist areas, which aligns with areas of high human activity. Originality. This is the first study of plastic waste in the coastal area using remote sensing data in Thanh Hoa province, Vietnam. Practical value. This study can contribute to the effective management of marine plastic waste in Thanh Hoa while opening up opportunities for applying the method to create marine plastic waste maps throughout Vietnam and foster long-term monitoring and management.

Environmental legislation analysis improvement approach of global marine plastic pollution from the perspective of holistic system view

Marine plastic pollution (MPP) has posed an unavoidable challenge to the conservation of marine ecosystems, escalating at an unprecedented rate. It extends beyond visible pollution, infiltrating the food chain and microcirculation, ultimately affecting the life and health of marine organisms. Of even greater concern is the fact that MPP has been found to penetrate human bloodstreams. The international community increasingly focuses on MPP, and has formulated a series of laws and regulations. This article analyses marine pollution prevention legislation within the context of international environmental resolutions and conventions, including those established by the United Nations, the European Union law and the domestic legislation of sovereign states. It is evident that the current legislation has played a pivotal role in the preventing MPP. However, global legislation on preventing MPP remains fragmented. The problems existing in the current legislation should be reviewed from the holistic systems perspective, and the integrity and systematicness of new plastics convention should be demonstrated. The proposed Marine Plastics Convention should emphasize environmental justice, protect the rights of vulnerable populations, lower the threshold for risk prevention, and focus on addressing residual risks. It must include clear provisions for regulating hydrosphere plastic pollution (HPP) to mitigate land-based pollution and scientifically define fundamental legal concepts to foster coordinated action among States. Moreover, the convention should establish standardized monitoring methodologies and assessment criteria to ensure accurate evaluation of the pollution status.

Mapping the sources and strands of marine debris via particle modelling and In-situ sampling approaches in archipelagic countries

Marine debris (MD) is a global issue that remains unresolved in Indonesia where the accumulation of this kind of pollution poses a significant threat to the marine ecosystem and health of the ocean. Understanding the sources and locations of stranded debris is crucial in identifying the required regulations and mitigation strategies. This study used the hypothetical sources to identify the stranded debris along the coastline of Selayar Island and its surrounding seas. Using a combination of simulation and in-situ sampling methods, the simulation considered 13 hypothetical sources based on external factors such as river locations and surface ocean currents. This simulation result was then validated the simulation against beach litter observations and interview results with people. The results successfully mapped the sources and stranded MD in Selayar Island, indicating that the majority of MD originates from the island itself and the surrounding areas, influenced by oceanographic factors. The most frequently encountered locations of stranded MD are in the western coastal region including tourism areas and coastal ecosystem. Due to the oceanographic conditions, the stranded debris has varied quantities over the months, and higher in December represent the northwest monsoon (NWM) season, exceeding levels observed during the southeast monsoon (SEM). The study also identified that the main sources of debris are from Selayar Island and rivers from surrounding islands. This study also confirmed that oceanographic conditions such as surface ocean currents and wind pattern influenced the spreading of MD in Selayar Island. Due to the different ocean characteristics in different regions, a more detailed understanding and stranded of marine debris source which might provide more information for the explanation of the mechanism of marine debris pathways in Archipelagic Countries.

The persistent DDT footprint of ocean disposal, and ecological controls on bioaccumulation in fishes

Globally, ocean dumping of chemical waste is a common method of disposal and relies on the assumption that dilution, diffusion, and dispersion at ocean scales will mitigate human exposure and ecosystem impacts. In southern California, extensive dumping of agrochemical waste, particularly chlorinated hydrocarbon contaminants such as DDT, via sewage outfalls and permitted offshore barging occurred for most of the last century. This study compiled a database of existing sediment and fish DDT measurements to examine how this unique legacy of regional ocean disposal translates into the contemporary contamination of the coastal ocean. We used spatiotemporal modeling to derive continuous estimates of sediment DDT contamination and show that the spatial signature of disposal (i.e., high loadings near historic dumping sites) is highly conserved in sediments. Moreover, we demonstrate that the proximity of fish to areas of high sediment loadings explained over half of the variation in fish DDT concentrations. The relationship between sediment and fish contamination was mediated by ecological predictors (e.g., species, trophic ecology, habitat use), and the relative influence of each predictor was context-dependent, with habitat exhibiting greater importance in heavily contaminated areas. Thus, despite more than half a century since the cessation of industrial dumping in the region, local ecosystem contamination continues to mirror the spatial legacy of dumping, suggesting that sediment can serve as a robust predictor of fish contamination, and general ecological characteristics offer a predictive framework for unmeasured species or locations.

Exploring the Sources of Marine Debris and their Effects on Magogoni Ferry Operations Efficiency

Marine debris poses significant challenges to the operational efficiency of the Magogoni Ferry in Dar es Salaam, Tanzania. This study investigates the sources of marine debris in the ferry's operational environment and evaluates their effects on operational efficiency. Field surveys, interviews, observations, and document reviews were conducted to identify debris sources and quantify their impacts on ferry operations. Findings indicate diverse debris origins, including urban waste, coastal littering, and shipping activities, contributing to operational disruptions through increased maintenance needs and service delays. The study underscores the importance of debris management strategies for sustaining ferry operations. It was found that a large quantity of marine debris reaching the Magogoni Ferry was brought by rivers during the rainy seasons, namely River Tegeta, River Mzinga, and River Msimbazi. Marine debris which impairs ferry operations at Magogoni Ferry includes fishing lines, fishing nets, wood, ropes, textiles, and plastic bags. The effects were seal damage, pump jet blockage, impeller entanglement, mechanical obstruction of the pump jet, and engine stoppage. These breakdowns cause navigational hazards, environmental pollution due to oil leakages, and increased costs of maintenance. It was found that between 2019 and 2023, the cost of maintenance due to breakdowns, whose sources were established to be marine debris, amounted to an average of Tsh120 million per year. to ensure the ferry channel is safe for navigation it was recommended to make it free from debris through implementing educational campaigns to raise awareness, regular cleaning, prohibiting fishing by angling near the ferry area, and the use of technology both to block the entrance of land-based waste to the sea and to improve ferry systems by making them able to withstand debris challenges, for example, the introduction of cutting blades to cut nets, ropes, and fishing lines, protecting the propulsion components.

Recommendations and challenges for the regulations of ghost fishing gears

ABSTRACT Approximately 80% of goods are transported by shipping all over the world. Shipping plays an indispensable role in international transportation, as it is the most effective method. However, marine pollution from ships, such as accidental or operational discharge, is a recognised contributor to the worsening marine environment and ecosystem. It is known that approximately 27% of plastic pollution originates from marine-based sources. Shipping is a major contributor to marine plastics through fishing gear and container losses as well as recreational boating and passenger ships, among others. Given the statistics, this study proposes future regulatory recommendations for mitigating marine plastic pollution from ships. The uniqueness of this research lies in its emphasis on regulatory analysis specific to ship-source plastic pollution, which differs from the usual focus on land-based origins. Ultimately, the study seeks to heighten public awareness regarding the urgency of implementing regulatory measures. The research suggests the strengthening of enforcement regime over vessels, advocating for revisions to Annex V of the MARPOL 73/78 Convention, and enhancing collaboration between the IMO and the FAO.

Beach wrack as a potential microplastic hot spot in the South-Eastern Baltic Sea environment

Beach wrack is considered as a major source of nutrients to the sandy coast ecosystems in the South-East Baltic Sea, and it serves as the natural beach sediment storage and habitat formation material. However, it also could be a hot spot for microplastic and other types of marine litter accumulation. We carried out the recovery rate experiments to determine the most reliable method for a rapid and cost-effective application to extract microplastics from the beach wrack. The aeration of media in a saturated solution of sodium chloride revealed to be statistically significant and reliable, therefore was selected as a most suitable to extract the microplastics from the beach wrack. This study shows that the concentration of microplastics is significantly different between the four analyzed compartments in the coastal zone. The microplastic concentration in a beach wrack, with a mean value of 0.47 ± 0.17 items/cm3, contained 4.7 times more microplastics than observed in the surface sand samples. This study estimated that on average over 450 million microplastic items could be found during the castaway event in the South-East Baltic Sea coast.

Assessment of transboundary macro-litter on the remote island of Andaman and Nicobar: Unveiling the governing factors and risk assessment

The increasing occurrence of mismanaged plastic litter along India's coastline and the ominous challenges it poses to biodiversity and ecosystem health is a growing environmental concern. To address this issue, we comprehensively investigated the abundance, composition, and probable sources of marine litter on North Cinque Island, a remote uninhabited island in the Andaman and Nicobar archipelago, Bay of Bengal. This island is a designated wildlife sanctuary and serves as an important nesting site for Green, Hawksbill and Leatherback turtles. A total of 6227 litter items were enumerated, with an average concentration of 0.12 items/m2, representing 20 diverse litter types, with plastic dominating the litter composition (86 %). The cleanliness and environmental hazards of the coast due to the litter were assessed using different indices such as the Clean Coast Index (CCI), Plastic Accumulation Index (PAI), Hazardous Item Index (HII), and Clean Environment Index (CEI). CCI indicates the moderately clean-to-clean status of the surveyed sites. PAI points to low to moderate accumulation of plastic litter. HII of all five coasts fell in category II, suggesting a moderate abundance of hazardous items that can inflict injuries to the foraging turtle and their hatchlings. The CEI articulates the moderately clean to very clean status of the sites. Litter brand audit suggests a considerable amount of stranded litter on the coasts was transboundary and originated from six Indian Ocean Rim Countries (IORC), namely Thailand, Myanmar, Malaysia, Indonesia, Sri Lanka, and UAE. Joint solid waste management by the IORC is the need of the hour to avert litter accumulation on the pristine, remote islands.

Optical Remote Sensing Methods for Floating Marine Debris Detection – Review and Bibliography Analysis

In the last several decades, the disposal and accumulation of debris in the marine and coastal environment has been one of the biggest and fastest-growing threats to the health of the world's oceans. Marine debris is present in all marine habitats and represents a great danger to global environmental and human health. Therefore, this paper aims to support efforts to achieve Good Environmental Status with respect to marine debris in all oceans and seas. The application of optical remote sensing methods for floating marine debris detection was briefly reviewed and the bibliometric analysis of the professional and scientific literature elaborated upon. In the overview part, previously used marine debris detection methods have been listed. The WoSCC (Web of Science Core Collection) and Scopus databases were considered, and the R Studio Bibliometrix and Biblioshiny software tools used for bibliometric analysis. 209 documents that can be classified into 43 research fields were identified in the two databases. Approximately 20% of the documents were published in two journals: the Marine Pollution Bulletin and Remote Sensing. Marine debris research was mainly published in the USA, Portugal, Italy, the United Kingdom, Germany, and China. A total of 54 countries participated in the publication of documents and it should be emphasized that all countries have shown great interest in international cooperation during the scientific research on marine debris. Scientific research on marine debris was found to have increased significantly since 2017, which is highly important for the protection of the environment and human health.

Indoor laboratory experiments for beach litter spectroradiometric analyses.

Marine pollution is a growing global issue, impacting both marine ecosystem and human health. High quantities of debris, mainly composed by plastic items, have been identified both in the coastal area and in the sea environment. Remote sensing techniques represent an useful tool (complementary to the in-situ campaigns) to monitor litter in the coastal environment, especially if the spectral signatures of the debris are known. In this framework, harvested beach litter (plastic items especially) were collected from two sandy beaches. The samples were spectrally characterised by implementing two indoor laboratory experiments with the aim to infer the best wavelengths to be used for beach litter detection via the spectral angle mapper index. Due to lack of a scientific protocol concerning the spectral data acquisition, two experimental setups were carried out to simulate the direct and diffuse illumination conditions. For around 30% of the samples, the spectral signatures are influenced by the two experimental setups. Outcomes suggest that for the majority of the samples green, blue, red-edge and some infrared bands are suitable for the beach litter detection.

Pollution and health risk assessments related to heavy metals on three prominent beaches in Makkah Province, Kingdom of Saudi Arabia: Concerning levels of cadmium pollution.

Beach pollution can impact the health of people living in or visiting coastal areas. The primary goal of this research was to investigate the presence of heavy metal pollutants and associated health risks in three distinct coastal cities, Jeddah, Al-Lith, and Al-Qunfudhah, located along Saudi Arabia's Red Sea coast. Forty-three soil samples were collected from different locations, heavy metals including Fe, Zn, Mn, Cu, Cd, and Pb were isolated, and analyzed using inductively coupled plasma optical emission spectroscopy. Various metrics such as pollution indices (PI), integrated pollution indices (IPI), enrichment factors (EF), daily dose averages (ADD), hazard quotients (HQ), and hazard indices (HI), as well as principal component analysis (PCA) and cluster analysis were employed to evaluate the environmental impacts and health risks posed by these heavy metals. The results revealed that Fe, Pb, Cu, Mn, and Zn concentrations in beach zones were below their respective background levels, while concentrations of Cd exceeded corresponding background levels. PCA revealed the highest levels of Pb, Fe, and Mn on Al-Qundudah beach, while Cd and Cu were highest on Al-Lith beach, and Zn was highest on Jeddah beach. PI values highlighted extremely high levels of Cd pollution on all designated beaches. The findings provide a foundational basis for further investigations into health problems potentially related to Cd contamination, such as chronic kidney disease (CKD), osteomalacia, and osteoporosis.

Bringing the Ocean to the Stage: Performing Coastal Values and Marine Management

Recent years have witnessed a seemingly constant call for improved understanding of human–ocean relationships, resulting in a “boom” of marine social science research, sometimes framed through the lens of ocean literacy. Defined as having an understanding of your influence on the ocean, and its influence on you, ocean literacy has gained traction in recent years as a way of better understanding the complexities of human–ocean relationships. However, despite this interest in the human dimensions of the ocean, coasts and seas, and a corresponding increase in broader marine social sciences research, qualitative and arts‐based research approaches continue to remain on the periphery of ocean research. This article explores the role of two ocean research “outliers,” intersecting arts‐based practice and marine social sciences through the lens of interconnected performances designed to explore the diverse values held by communities about their marine and coastal environment. Undertaken as part of the Diverse Marine Values project, the performances brought together ocean scientists, coastal and marine managers, and community members to create original performance pieces in Lerwick, Shetland, Scotland, and Portsmouth, England. Drawing heavily on applied theatre practice and scholarship, these distinct but interrelated performances utilised elements of forum theatre, devised theatre, and storytelling to address marine issues important to each respective community, with a view to understanding and fostering ocean literacy. In each location, the performance work illustrated ways in which theatre can serve as not only a tool for science communication, but also a research method to explore a range of ocean literacy dimensions. The performances helped the research team, comprised jointly of specialist theatre practitioners and experts in ocean literacy, coastal management, and plastics pollution to reshape data collection and stakeholder engagement. This collaborative theatre‐making process led to deeper conversations and embedded engagement within each coastal community. It also led to a fundamental reshaping of the questions and approaches that the marine managers and scientists asked of the communities in question. The article presents a discussion of the challenges of bridging these related, but often distant, disciplines, and highlights the role of arts‐based research practice in broader ocean literacy research and discourse.

Cultural and socio-demographic drivers shape seahorse uses in Malaysia: implications for conservation

Abstract Seahorses Hippocampus spp. are commercially and culturally important to many communities. Although seahorses are widely used in traditional medicine, as curios and as aquarium fishes in Southeast Asia, documentation on the current nature and extent of culturally motivated seahorse uses in Malaysia is lacking. To examine how ethnicity and other socio-demographic drivers shape traditional medicinal use and underlying cultural beliefs involving seahorses, we administered a questionnaire-based survey during March 2021–April 2022 to members of the general public and fishers in Malaysia. Approximately one-fifth (21.0%) of respondents reported consuming seahorses (34.4% of these used seahorses for medicinal purposes, 55.2% for other non-medicinal uses and 10.4% for both types). Consumers of seahorses were from all ethnic groups except for Indigenous groups. In the general public group, medicinal use was more common amongst the Chinese respondents, whereas in the fisher group, other uses were more common amongst the Malay respondents. Amongst the threats facing seahorses, which include overfishing, habitat destruction, bycatch and ocean plastic pollution, only bycatch was perceived as a major threat by most of the general public and fisher respondents. The relatively low prevalence of reported seahorse use amongst Malaysians is an encouraging finding from a conservation perspective. However, the high proportion of non-medicinal uses indicates the need to focus on such other uses to ensure the sustainability of seahorse use in Malaysia.

Penanganan Sampah Laut di Indonesia : A Review

Indonesia produces 33,113,277.69 tons of waste per year, in which 13,455,925.41 tons are unmanaged waste. From these data, it can be seen that Indonesia is still experiencing problems in waste management. Unmanaged waste is at risk of being carried away by river currents that lead to the sea., Not only land-based waste, marine debris must also be adressed. Marine debris could possibly come from activities on land or at sea. Marine debris consists of three categories; macro, meso and micro marine debris. This paper is a narrative-review on how to dealt with marine debris in Indonesia. Several methods have been done by the Indonesian government to dealt with marine debris. In 2018, the Indonesian government issued Presidential regulation number 83 of 2018, concerning the handling of marine debris. Besides that, Indonesian government also formed National Plan of Action (NPOA) and opened itself to foreign investors to invest on that action plan, especially on adressing marine plastic debris. In addition to forming special team and supporting regulations, the complexity of marine debris problems must also be resolved by integrated research on marine debris, and also make changes on Indonesian human resources‘ mentality and mindset.

Passing plastic: Traces of plastic in the fecal samples of a high Arctic seabird in Tunu (East Greenland)

Arctic seabirds are key bio-indicators of marine plastic pollution due to their transient movement and large populations. Although many studies have quantified the ingestion of microplastic particles (<5 mm in size) through necropsy or regurgitation sampling methods, little is known about post-digestive particle excretion. Due to the logistical challenges of non-lethally sampling feces from Arctic seabirds, this pathway remains largely understudied. We non-lethally collected 110 fecal samples from little auks (Alle alle) during the 2014 breeding season in Ukaleqarteq, Tunu (Kap Höegh, East Greenland). We identified 25 potential microplastic particles (>100 µm in size), 19 of which were analyzed for material composition using Fourier Transform Infrared Spectroscopy and Raman micro-spectroscopy. Of these, 13 particles were successfully matched to materials, with five as plastic. This produced an average concentration of 0.08 ± 0.28 microplastic particles per fecal sample, with no difference of occurrence between chicks and adults. Particle lengths ranged from 113 - 751 µm. The presence of microplastics larger than our lower limit of detectability of 100-µm suggests a need for analysis of smaller particles and microfibers in this species. We contribute to understanding how microplastics pass through little auks and characterize how this species interacts with the plastic pathways.

Face mask littering in coastal environment of Coromandel beaches, a comparison between street and beach littering - perspective and perceptions.

The usage of face mask has been encouraged globally to combat the COVID-19 pandemic. However, their improper disposal has begun to impact the environment. In the present study, face mask littering was assessed in sixteen stations across the beaches in Coromandel coast of South India for a period of four weeks. Moreover, an online questionnaire was recorded to evaluate the people's perception about face mask usage and littering. In terms of land use pattern, stations with both fishing and tourism activities had higher abundance of face mask littering when compared with exclusive fishing and tourism stations. The study also found that mask littering was higher in streets when compared to the beaches. Of 163 respondents, most of the respondents preferred using disposable single use masks and 39.9% of the respondents preferred to dispose of the face masks along with other wastes. The study highlights the lack of proper solid waste management, negligent littering, and the need for raising awareness, strategic intervention to control this menace.

Momentum, energy and vorticity balances in deep-water surface gravity waves

The particle trajectories in irrotational, incompressible and inviscid deep-water surface gravity waves are open, leading to a net drift in the direction of wave propagation commonly referred to as the Stokes drift, which is responsible for catalysing surface wave-induced mixing in the ocean and transporting marine debris. A balance between phase-averaged momentum density, kinetic energy density and vorticity for irrotational, monochromatic and spatially periodic two-dimensional water waves is derived by working directly within the Lagrangian reference frame, which tracks particle trajectories as a function of their labels and time. This balance should be expected as all three of these quantities are conserved following particles in this system. Vorticity in particular is always conserved along particles in two-dimensional inviscid flow, and as such even in its absence it is the value of the vorticity that fundamentally sets the drift, which in the Lagrangian frame is identified as the phase-averaged momentum density of the system. A relationship between the drift and the geometric mean water level of particles is found at the surface, which highlights connections between the geometry and dynamics. Finally, an example of an initially quiescent fluid driven by a wavelike pressure disturbance is considered, showing how the net momentum and energy from the surface pressure disturbance transfer to the wave field, and recognizing the source of the mean Lagrangian drift as the net momentum required to generate an irrotational surface wave by any conservative force.