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Plastic pollution in river environments has become an emerging global concern. However, the migration of plastic and changes in its properties between river compartments are less understood. This study demonstrates the plastic debris aging and the dynamics between floodplain, surface water, and sediment compartments of the Tuul River, Mongolia. Plastic occurrence is evaluated in terms of their abundance, size, shape, polymer type, and photodegradation in each compartment. Photodegradation stages were calculated using the carbonyl index (CI). Plastic abundance was 5.46 ± 3.53 items m−2 in the floodplain, 155 ± 100.7 items m−3 in the surface water, and 128.4 ± 76.3 items kg−1 in the sediment. Microplastics dominated in the size category in all compartments, while macro- and megaplastics were found only in the floodplain. Polyethylene and polypropylene dominated the surface water and sediment, while polystyrene was the predominant plastic in the floodplain. A positive correlation was found between the distributed polymer types in the surface water and sediment compartments. The similar composition in size and polymer type suggests vertical plastic migration from water to sediment. Although CI values showed that the plastic aging was significantly different between water and sediment (water, 0.61 ± 0.26, and sediment, 0.90 ± 0.68), the dominance of low-density plastics with high CI in the sediment suggests that the aged plastic density changed during the vertical transport in the river system. [ABSTRACT FROM AUTHOR]

Plastic pollution in the hydrosphere ranks among the most pervasive environmental issues since the inception of the plastic industry and its widespread use in our daily lives. Nowadays, numerous countries worldwide suffer from this pollution not only along coastlines but also in deep-sea ecosystems. Our study carried out in the Gulf of Annaba aims to assess the prevalence and spatial distribution of plastic waste. Sampling was conducted at four coastal sites: El Battah, Seybousse, Rizzi Amor, and Ain Achir, both before and after the Covid-19 pandemic. The results reveal varying rates of macro and microplastic contamination, influenced by geographical differences, urban activities, and hydrodynamic factors. Moreover, the proportions of contamination depend on the types of waste. Furthermore, our study showed a clear divergence, particularly in two periods before and after the pandemic. Due to the lockdown, implemented in 2020, there was a marked decrease in the percentage of sediment plastic pollution, attributed to reduced human activity and partial cessation of industrial operations in these areas. [ABSTRACT FROM AUTHOR]

This study is the first report evaluating the microplastic (MP) and macroplastics capture potential of Pontederia crassipes. Total of 3691 (508 microplastic and 3183 macroplastic) particles were extracted from the roots of 12 examined specimens. Mean macroplastic abundance in the roots was found as 265±44 macroplastic/specimen. Majority of the extracted macroplastics were fragment in shape, blue in color. Mean microplastic abundance was found as 42±23 MPs/specimen. Majority of the extracted microplastics were fragment in shape, blue in color and less than 500 µm in size. Results of this preliminary study showed that this species have significant ability to adsorb micro and macroplastics by the roots which makes them perfect employees for integrated floating systems. [ABSTRACT FROM AUTHOR]

The present study described the most recent findings concerning the abundance and distribution of plastic in water, sediment, and fauna in the Nile River of Upper Egypt as an interesting research point. The findings revealed that plastics were abundant in the water, sediments, fish, and crayfish throughout the sites. The Nagaa Hammadi site has the highest abundance of meso- and macroplastics in its water and sediment. African catfish had the highest abundance of meso- and macroplastics compared to the other species, while Nile tilapia had no meso- or macroplastics in its alimentary canal or gills in all sites. The Edfu site has the highest abundance of mesoplastics in the alimentary canals of African catfish, while the Nagaa Hammadi site has the highest abundance of mesoplastics in the gills, and macroplastics appeared only in the alimentary canal of African catfish from the El-wasta site. Only mesoplastics were found in the crayfish's alimentary canal, with the Nagaa Hammadi site having the highest abundance. No macroplastics were detected in the crayfish's gills or alimentary canal. Additionally, this work lets us understand how plastics behave in freshwater environments, and it is a step toward decision-makers taking appropriate measures to reduce their risk. [ABSTRACT FROM AUTHOR]

Background: Plastic greenhouse farming has become widespread worldwide because of its contributions to various agricultural production. However, it also generates plastic waste in large quantities and pollutes farmlands. Contrary to studies on microplastics, few studies have quantified macroplastic contamination in agricultural farmlands despite its contribution to the production of microplastics through fragmentation. Thus, there is a paucity of knowledge on the levels and characteristics of macroplastics in greenhouse environments. Thus, this study aimed to quantify and examine the macroplastic litter on soil surfaces under fallow greenhouse farmlands. Results: The study was conducted at three sites in Southern Hungary, where the usage of plastic greenhouses is very common for cultivating vegetables. On the studied fallow plots, the overall mean abundance of macroplastics was 431 pieces/ha or 6 kg/ha. Most of the fragments had 0.5- to 5-cm sizes. The macroplastic fragmentation in the area was well detected and was an ongoing process. The dominant plastic types were polyethylene and polyvinyl chloride in the form of films and fragments. The results showed that agricultural litter comprised 90% of the total contamination, whereas nonagricultural litter (10%) due to illegal littering also appeared on the plots. Conclusions: Given that macroplastics were found in the studied greenhouse farmlands, we recommend the following: (1) careful cleaning and disposal of plastics on greenhouse farmlands and (2) prevention of greenhouse farmland contamination by external and nonagricultural contaminants. Besides, further research is needed to elucidate the duration of macroplastic fragmentation to microplastic contaminants in greenhouse environments. [ABSTRACT FROM AUTHOR]

Plastics have brought many benefits to society, but their mismanagement has turned them into a serious environmental problem. Today, the effects of plastic waste on wildlife are becoming increasingly evident. Since studies on plastic pollution have focused on species in marine ecosystems, here we review current knowledge on interactions between terrestrial mammals and plastic waste in the countries of the Americas, which is a global hotspot of mammalian biodiversity and in turn has, among its member countries, nations with high per capita generations of plastic waste globally. We identified 46 scientific articles documenting plastic ingestion in 37 species and four species that used plastic waste for nest or burrow construction. Of the 46 investigations, seven focused on plastic contamination, while the others reported on the presence of plastics in wildlife, even though this was not the primary focus of the research. However, these publications lack analytical methods commonly used in plastic studies, and only one study applied a standardized methodology for plastic detection. Therefore, in general, plastic pollution research on terrestrial mammals is limited. We extend several recommendations such as designing methodologies that are adapted to terrestrial mammals for the identification of plastics in fecal matter or gastrointestinal contents, carrying out species-specific analyzes on the impacts of plastics in nests or burrows, and giving further attention to this understudied issue and taxa. [ABSTRACT FROM AUTHOR]

Macrolitter, especially macroplastics, (> 0.5 cm) negatively impact freshwater ecosystems, where they can be retained along lake shores, riverbanks, floodplains or bed sediments. Long-term and large-scale assessments of macrolitter on riverbanks and lake shores provide an understanding of litter abundance, composition, and origin in freshwater systems. Combining macrolitter quantification with hydrometeorological variables allows further study of leakage, transport, and accumulation characteristics. Several studies have explored the role of hydrometeorological factors in influencing macrolitter distribution and found that river discharge, runoff, and wind only partially explains its distribution. Other factors, such as land-use features, have not yet been thoroughly investigated. In this study, we provide a country-scale assessment of land-use influence on macrolitter abundance in freshwater systems. We analyzed the composition of the most commonly found macrolitter items (referred to as 'top items', n = 42,565) sampled across lake shores and riverbanks in Switzerland between April 2020 and May 2021. We explored the relationship between eleven land-use features and macrolitter abundance at survey locations (n = 143). The land-use features included buildings, city centers, public infrastructure, recreational areas, forests, marshlands, vineyards, orchards, other land, and rivers and canals. The majority of top items are significantly and positively correlated with land-use features related to urban coverage, notably roads and buildings. Over 60% of top items were found to be correlated with either roads or buildings. Notably, tobacco, food and beverage-related products, as well as packaging and sanitary products, showed strong associations with these urban land-use features. Other types of items, however, did not exhibit a relationship with land-use features, such as industry and construction-related items. Ultimately, this highlights the need to combine measures at the local and regional/national scales for effective litter reduction. [Display omitted] • 60% of macrolitter items at freshwater shores correlate with roads or buildings. • Industry and construction items show insignificant correlations with local land use. • Results suggest combining local and regional/national litter reduction measures. [ABSTRACT FROM AUTHOR]

The research on the impact of plastic pollution on biodiversity has primarily focused on aquatic ecosystems, especially marine ones. Therefore, it is vital to assess how plastic pollution affects other environments and organisms, including terrestrial invertebrates. These organisms are widely recognized for their susceptibility to environmental changes and pollution. The objectives of this study were i) to investigate the potential influence (positive or negative) of macroplastic debris (MaP) on invertebrates inhabiting riverine sandy environments, ii) the potential occurrence of the microplastic (MP) adherence phenomenon on the invertebrate's body by entanglement on the body's setae or electrostatic effect (i.e., bioadhesion), and iii) the effects of removal of debris on the colonized diversity. By performing a mesocosm experiment, emulating a "small-scale dump" (also called micro-waste sites), we found that terrestrial invertebrates show a preference for colonizing areas rich in MaP, resulting in higher species richness in these areas (39 taxa in areas containing plastic debris vs. 21 taxa in areas free of plastics). This preference is likely due to the provision of shade, protection, and distinct micro-habitats offered by MaP. Regarding MP, we observed a significant number of invertebrates with MPs attached to their bodies (4.3 ± 0.8 MPs attached per individual), mainly wolf spiders (Lycosidae) and ground beetles (Carabidae), suggesting potential negative ecological implications that are discussed herein. [Display omitted] • Terrestrial invertebrates showed greater diversity in areas affected by plastics. • Small-scale dumps can serve as refuges and feeding grounds for invertebrates. • Invertebrates exhibited bioadhesion of microplastics on their bodies. [ABSTRACT FROM AUTHOR]

Plastic waste has become a hot topic in sustainability and conservation, helped in part by popular documentaries which have highlighted the issue to the general public. Much of the current literature focuses on the effect of microplastics in the marine environment, with very little information on macroplastic interactions or the terrestrial environment. In this report, the management of digit constriction due to macroplastic debris in a Verreaux's eagle owl (Bubo lacteus) is presented, and the role of zoos in decreasing littering behaviour both within the collection and in the wider global context is discussed. [ABSTRACT FROM AUTHOR]

Literature review identified seven principal pathways of plastic debris entry into river systems: waste water treatment plants; combined sewer overflows; on-site wastewater treatment systems; road and rail transport systems; agriculture; industrial sources; and diffuse litter. A further category of 'microplastics' reflects their multiple potential sources, including microplastic breakdown within rivers. Regulatory and management bodies necessarily make operational decisions based on resource limitations and significant uncertainty due to sparse or missing data, requiring a substantial degree of inference. To support this need, we develop a rapid, desk-based approach based on risk criteria to 'fingerprint' likely pathways of plastic pollution based on catchment characteristics. Characteristics of the River Wye system in the UK are reviewed identifying a risk-based 'fingerprint' of potential pathways of plastic entry or accumulation of plastic debris, represented graphically as a colour-coded 'traffic lights' classification. This 'fingerprinting' approach is based on desk-based inference from published materials as a rapid and resource-efficient alternative to intensive data collection, supporting prioritization of further investigation or response measures. We recommend replication of this 'fingerprinting' approach in other river catchments to support operational management of plastic pollution. Where feasible, it may also be down-scaled where sub-catchment or major river reach properties differ significantly. HIGHLIGHTS Unique catchment characteristics influence likely sources of plastics in rivers Seven potential plastic sources were identified, with a residual microplastics category Literature, interviews and surveys can rapidly 'fingerprint' likely plastic sources Fingerprinting can prioritize management and investigations in specific catchments [ABSTRACT FROM AUTHOR]

Microplastic (MP) pollution has been widely reported across water matrices including in estuaries, which are important for the understanding of oceanic MPs. Estuaries can greatly alter the fate, transport, size distribution, and abundance of plastic pollution. The aim of this study was to quantify and characterize MP pollution in the Delaware Bay estuary USA, including the size distribution. Samples (N = 31) were collected from the mouth of the Delaware River to the coastal ocean including multiple frontal zones across two sampling campaigns (2019 and 2022). MP were extracted from the collected particles using wet peroxide oxidation and density separation with saturated sodium chloride. Particles collected on 500 μm mesh sieves were analyzed via Fourier transform infrared (FTIR) spectroscopy. Across all samples, 324 of the 1015 particles analyzed were MP, and 11 macroplastics were observed. MP concentrations ranged from below detection to 4.12 MP/m3 (mean 0.34 ± 0.80 MP/m3). No significant differences were observed between sampling sites; nonetheless, the two highest MP concentrations were observed when sampling along frontal zones with visible debris including macroplastics. Polyethylene (53%) and polypropylene (43%) were the most abundant polymers observed. The majority of the non-plastic particles were classified as particulate natural organic matter (82% of non-plastics). Particles from samples collected during 2022 (N = 864) also had color, morphology, and two size dimensions recorded. MP particle size was significantly associated with sampling site, with the coastal ocean sampling site generally having the smallest MPs. A correlation between total post-extraction particles and total plastic particles was observed. Aspect ratios for the plastics ranged from one to 40.7, with larger ratios for fibers, with a mean (±standard deviation) of 3.39 ± 4.72 (unitless). These aspect ratios can be used to select shape factors used to estimate the total volume of MP in the studied size range. Overall, these results can help inform fate, transport, and risk assessments related to estuarine plastic pollution. [Display omitted] • Polyethylene and polypropylene were most prevalent MP in the Delaware Bay estuary. • Peak plastic concentrations were observed in frontal zones. • Microplastic particle size varied by sampling site, sometimes by polymer type. [ABSTRACT FROM AUTHOR]

Quantifying microplastics (MPs) in marine environments is challenging due to the complexities of differentiation from other materials. This study aims to distinguish petro-sourced plastic microfilaments from organic ones in environmental samples using scanning electron microscope coupled with energy dispersive X-ray (SEM-EDX) analysis. Therefore, 38 particles resembling MPs (PRMPs) from sediments and organisms in Madagascar were analyzed. MPs identification thresholds were determined from SEM-EDX analysis of macroplastics and seaweed, the primary sources of microfilaments. SEM-EDX results of the 38 PRMPs were compared with identification/misidentification made by five MPs observation experts. Results indicated that a carbon/oxygen (C/O) ratio >1 distinguished macroplastics and MPs from other sources (seaweed and organic microfilaments). SEM-EDX analysis identified 81.58% of PRMPs as MPs. The average error made by one observer was 36.32%. These findings highlight the need for a method to assess identification error in MPs quantification and recommend SEM-EDX analysis of microfilaments to gauge observer error. • SEM-EDX reveals atomic differences between organic and petro-sourced microfilaments. • Higher C and O content in macroplastics but biofouling alters these ratios. • C/O ratios facilitate the distinction between plastic microfilaments and organic ones. • Visual identification differs from SEM-EDX, indicating microplastic underestimation. • Petro-sourced microfilaments predominate, highlighting marine pollution in Madagascar. [ABSTRACT FROM AUTHOR]

This study aims to present the identification, abundance, and chemical characterization of plastics in the intertidal zone sediment of two selected beaches in Kota Kinabalu city, Sabah, Malaysia. Plastic debris was classified according to weight and size and was identified for its heavy metal concentrations and polymer types. Results showed that a higher abundance, by more than 2-fold, of plastic debris was found in Kebagu beach (28.7 g) compared to ODEC, UMS (13.4 g). FTIR analysis showed that polypropylene (PP) and polyethylene (PE) were the dominant plastic polymers on both beaches, followed by polystyrene (PS) and polyethylene terephthalate (PET). Five heavy metals (arsenic, chromium, copper, zinc, and nickel) were detected from four types of plastics. The results showed that the concentration of Zn was higher in all four types of plastics on both beaches, with a range of 41 mg/kg–135.3 mg/kg, followed by Cr and As, while Ni was the lowest concentration detected in PE on both beaches: 5.6 mg/kg (ODEC) and 5.1 mg/kg (Kebagu stations). This study confirmed the presence of macro-, meso- and microplastics in both stations. Further studies remain necessary for a better understanding of the sources and fates of the pollutant in the marine environment. Findings from the studies of the Kota Kinabalu beaches have provided baseline data and a clearer understanding of the distribution of plastic debris. This demonstrates that commitments and actions are required to mitigate the potential risk to the ecological system and human health. [ABSTRACT FROM AUTHOR]

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The presence of plastic in the environment is generating impacts on all habitats and has become a major global problem in marine megafauna. Macroplastics can cause entanglement, ingestion and loss of suitable habitats. In addition to entanglement problems, there is evidence that plastics are entering the food web through ingestion by marine organisms, which could ultimately be affecting humans. Much of the available information on the impact of plastic in biota is scattered and disconnected due to the use of different methodologies. Here, we review the variety of approaches and protocols followed to assess macro‐ and microplastic ingestion in marine vertebrates such as sea turtles, cetaceans and fishes in order to offer a global overview of their current status. The analysis of 112 studies indicates the highest plastic ingestion in organisms collected in the Mediterranean and Northeast Indian Ocean with significant differences among plastic types ingested by different groups of animals, including differences in colour and the type of prevalent polymers. In sea turtles, the most prevalent types of plastics are white plastics (66.60%), fibres (54.54%) and LDPE polymer (39.09%); in cetaceans, white macro‐ and microplastics (38.31%), fibres (79.95%) and PA polymer (49.60%); and in fishes, transparent plastics (45.97%), fibres (66.71%) and polyester polymer (36.20%). Overall, clear fibre microplastics are likely the most predominant types ingested by marine megafauna around the globe. [ABSTRACT FROM AUTHOR]

Impacts generated by plastic pollution constitute one of the most significant challenges that humanity must face in the next century, receiving increasing attention from the society at large. Thus, quantifying the state of knowledge concerning organisms affected by plastic debris is extremely important to understand threats to marine species. In this context, this study aimed to review and quantify published data on which marine fish species have been reported as interacting with plastic waste through a scientometric analysis carried out on the Web of Science, Scopus and Scielo databases, using a combination of keywords and Boolean operators. Despite no results for Agnatha, Holocephali and Sarcopterygii, this survey registered 116 documents reporting high intake and low entanglement interactions for 310 teleost species and 33 Elasmobranchs. The results indicate increased knowledge production after 2012, reporting a diversity of debris colors, shapes and materials distributed throughout the globe, but with greater research efforts performed in the Northeast Atlantic and the Mediterranean and Black Seas. This study provides analyses, perspectives and suggestions for future assessments, gathering information and seeking to better understand the issue concerning these debris, which represent another threat to the fauna of the world's oceans. [ABSTRACT FROM AUTHOR]

The growing and pervasive presence of plastic pollution has attracted considerable interest in recent years, especially small (< 5 mm) plastic particles known as 'microplastics' (MPs). Their widespread presence may pose a threat to marine organisms globally. Most of the nano and microplastic (N&MP) pollution in marine environments is assumed to originate from land-based sources, but their sources, transport routes, and transformations are uncertain. Information on freshwater and terrestrial systems is lacking, and data on nanoplastic pollution are particularly sparse. The shortage of systematic studies of freshwater and terrestrial systems is a critical research gap because estimates of plastic release into these systems are much higher than those for oceans. As most plastic pollution originates in urban environments, studies of urban watersheds, particularly those with high population densities and industrial activities, are especially relevant with respect to source apportionment. Released plastic debris is transported in water, soil, and air. It can be exchanged between environmental compartments, adsorb toxic compounds, and ultimately be carried long distances, with potential to cause both physical and chemical harm to a multitude of species. Measurement challenges and a lack of standardized methods has slowed progress in determining the environmental prevalence and impacts of N&MPs. An overall aim of this review is to report the sources and abundances of N&MPs in urban watersheds. We focus on urban watersheds, and summarize monitoring methods and their limitations, knowing that identifying N&MPs and their urban/industrial sources is necessary to reduce their presence in all environments. [ABSTRACT FROM AUTHOR]

The Eastern Tropical and South-Eastern Pacific region is of global biodiversity importance. At COP26, the governments of Costa Rica, Panama, Colombia, and Ecuador committed to the expansion of existing MPAs to create a new Mega MPA, safeguarding the Eastern Tropical Pacific Marine Corridor. It offers a profound step forward in conservation efforts but is not specifically designed to protect against the more diffuse anthropogenic threats, such as plastic pollution. We combine published data with our own unpublished records to assess the abundance and distribution of plastic pollution in the region. Macro- and microplastic concentrations varied markedly and were not significantly different when comparing areas inside and outside existing MPA boundaries. These findings highlight the diffuse and complex nature of plastic pollution and its ubiquitous presence across MPA boundaries. Understanding the sources and drivers of plastic pollution in the region is key to developing effective solutions. • Analysis of 430 sites to assess plastic pollution in ET/SE Pacific. • No significant difference in plastic levels inside/outside of Marine Protected Areas. • New Mega MPA will not protect against ingress by plastic pollution. • Imperative to clearly establish sources and drivers of plastic pollution in region. [ABSTRACT FROM AUTHOR]

The overwhelming majority of research conducted to date on plastic pollution (all size fractions) has focused on marine ecosystems. In comparison, only a few studies provide evidence for the presence of plastic debris in freshwater environments. However, owing to the numerous differences between freshwater studies (including studied species and habitats, geographical locations, social and economic contexts, the type of data obtained and also the broad range of purposes), they show only fragments of the overall picture of freshwater plastic pollution. This highlights the lack of a holistic vision and evidences several knowledge gaps and data biases. Through a bibliometric analysis we identified such knowledge gaps, inconsistencies and survey trends of plastic pollution research within freshwater ecosystems. We conclude that there is a continued need to increase the field-data bases about plastics (all size fractions) in freshwater environments. This is particularly important to estimate river plastic emissions to the world's oceans. Accordingly, data about macroplastics from most polluted and larger rivers are very scarce, although macroplastics represent a huge input in terms of plastics weight. In addition, submerged macroplastics may play an important role in transporting mismanaged plastic waste, however almost no studies exist. Although many of the most plastic polluted rivers are in Asia, only 14% of the reviewed studies were carried out in this continent (even though the major inland fisheries of the world are located in Asia's rivers). The potential damage caused by macroplastics on a wide range of freshwater fauna is as yet undetermined, even though negative impacts have been well documented in similar marine species. We also noted a clear supremacy of microplastic studies over macroplastic ones, even though there is no reason to assume that freshwater ecosystems remain unaffected by macro-debris. Finally, we recommend focusing monitoring efforts in most polluted rivers worldwide, but particularly in countries with rapid economic development and poor waste management. [ABSTRACT FROM AUTHOR]

Both macroplastic and microplastic contamination levels were assessed for the first time in a tropical river estuary system, i.e. the Saigon River, that traverses a developing South East Asian megacity, i.e. Ho Chi Minh City, Vietnam. The analysis of floating debris collected daily on the Nhieu Loc – Thi Nghe canal by the municipal waste management service shows that the plastic mass percentage represents 11–43%, and the land-based plastic debris entering the river was estimated from 0.96 to 19.91 g inhabitant −1 d −1 , namely 350 to 7270 g inhabitant −1 yr −1 . Microplastics were assessed in the Saigon River and in four urban canals by sampling bulk water for anthropogenic fiber analysis and 300 μm mesh size plankton net exposition for fragment analysis. Fibers and fragments are highly concentrated in this system, respectively 172,000 to 519,000 items m −3 and 10 to 223 items m −3 . They were found in various colors and shapes with smallest size and surface classes being predominant. The macroplastics and fragments were mainly made of polyethylene and polypropylene while the anthropogenic fibers were mainly made of polyester. The relation between macroplastic and microplastic concentrations, waste management, population density and water treatment are further discussed. [ABSTRACT FROM AUTHOR]

The analysis of microplastics (MP) is time-consuming which limits our capacity to monitor and mitigate plastic pollution. Here, near infrared (1000–2500 nm) hyperspectral imaging (NIR-HSI) offers an advantage over other spectroscopic techniques because it can rapidly image large areas relative to other systems. While NIR-HSI can successfully detect MP, accuracy and limitations of the method have not been fully explored. In addition, lack of open databases and analysis pipelines increases the barrier to use. In this work, we developed a spectral database containing preproduction pellets, consumer products and marine plastic debris, imaged using a Hyspex SWIR-320me imager. A SIMCA model identified four polymer types: polypropylene, polyethylene, polyethylene terephthalate and polystyrene (PP, PE, PET, PS) to identify MP in hyperspectral images. We determined the accuracy of size estimates for PS MP > 1000 μm using fluorescence microscopy and tested the impact of photooxidation on detection of plastics by NIR-HSI (PE, PP, PS, PET) and subsequent prediction by the SIMCA model. The model performed well across all polymers as shown by high specificity, sensitivity, and accuracy for internal cross validation (>88%), and sensitivity >80% for external validation. PS MP < 500 μm Feret diameter were not consistently detected by NIR-HSI when compared with fluorescence microscopy. However, estimates for Feret diameter were consistent for PS MP > 1000 μm. Analysis by NIR-HSI showed no spectral changes and SIMCA showed no decreased precision with increased photooxidation across polymer types. Recall varied across polymer type and photooxidation stage with no clear trends. This study shows that NIR-HSI is a rapid method which can accurately identify MP of the four most relevant polymer types, precluding the need to analyze particles one at a time. NIR-HSI can be a key technology for environmental monitoring of plastic debris where rapid analysis of multiple samples is required. [Display omitted] • Open spectral database and chemometric model for routine analysis of microplastics. • High performance in identifying microplastics made of four polymer types. • Hyperspectral imaging accurately characterized size of polystyrene microplastics >1000 μm. • Photooxidation did not affect precision of polymer identification. • Promising technique to increase analysis throughput for microplastic monitoring. [ABSTRACT FROM AUTHOR]

Rivers function as a pathway for plastic pollution to enter the marine environment. This study presents one of the first field estimates of macroplastic emissions from the Mahiga Creek into its estuary. Thirty-minute plastic counting surveys were conducted for 31 days with the use of videos and a collecting trawl. The captured plastics were classified according to the OSPAR marine litter manual. The three main categories were crisp packets (27.96 %), small bags (27.08 %), and plastic/polystyrene pieces (2.5–50 cm) (18.35 %). Intraday and daily changes in plastic flux values were compared. Plastic flux comparisons between holidays and regular days were also done. No relationship between plastic flux and discharge was found on days without rainfall (r = 0.0237). However, a significant increase in plastic flux was observed during rainfall events. The findings in this study present an insight into different factors that may affect macroplastic emissions in the Philippines. • Visual observations were used to estimate the emissions of a Philippines river. • The three most found items were crisp packets, small bag, and pieces (2.5–50 cm). • No plastic flux discharge relationship was observed on days without rainfall. • Visual counts were done during the Sinulog Festival and Lunar New Year. • The median hourly emission in this study was 468 items/h (352–604 items/h). [ABSTRACT FROM AUTHOR]

It was thought that the Southern Ocean was relatively free of microplastic contamination; however, recent studies and citizen science projects in the Southern Ocean have reported microplastics in deep-sea sediments and surface waters. Here we reviewed available information on microplastics (including macroplastics as a source of microplastics) in the Southern Ocean. We estimated primary microplastic concentrations from personal care products and laundry, and identified potential sources and routes of transmission into the region. Estimates showed the levels of microplastic pollution released into the region from ships and scientific research stations were likely to be negligible at the scale of the Southern Ocean, but may be significant on a local scale. This was demonstrated by the detection of the first microplastics in shallow benthic sediments close to a number of research stations on King George Island. Furthermore, our predictions of primary microplastic concentrations from local sources were five orders of magnitude lower than levels reported in published sampling surveys (assuming an even dispersal at the ocean surface). Sea surface transfer from lower latitudes may contribute, at an as yet unknown level, to Southern Ocean plastic concentrations. Acknowledging the lack of data describing microplastic origins, concentrations, distribution and impacts in the Southern Ocean, we highlight the urgent need for research, and call for routine, standardised monitoring in the Antarctic marine system. [ABSTRACT FROM AUTHOR]

Plastic pollution is ubiquitous within the marine environment, including surface waters, water column and benthic sediments. Marine plastic contamination is expected to increase if future projections of increased plastic production eventuate. Conversely, national and international efforts are aiming to reduce marine plastic contamination. In this context, scientists, managers and the general public are increasingly interested in understanding the status and temporal trends of plastic contamination in the marine environment. Presented here is the first temporal assessment of plastic contamination in surface waters of the Great Barrier Reef (GBR), Australia. Specifically, duplicate surface seawater samples (n = 66) were collected at the SS Yongala shipwreck (Central GBR) monthly from September 2016 to September 2019 and analysed for plastic presence and abundance. The processing workflow involved density separation, followed by filtration, visual identification and sizing of putative plastics using stereomicroscopy, and chemical characterisation using Fourier transform infrared spectroscopy. A total of 533 plastic items were identified across all tows, consisting of macro-, meso- and microplastic fragments and fibres, with polypropylene and polyethylene being the most common polymers. Plastic contamination was detected in every replicate tow, bar one. Plastic concentrations fluctuated and spiked every three months, although contamination did not significantly alter across the three-year period. Wind speed, salinity and river discharge volume, but not surface current speed nor sea surface temperature, had a significant influence on the levels of plastic contamination. This study reveals, for the first time, the chronic presence of plastic debris in the surface waters of the GBR highlighting the need for long-term and on-going monitoring of the marine environment for plastic contamination. [Display omitted] • PE and PP fragments and PEST fibres were most abundant microplastics (MPs). • GBR surface plastic contamination varied, albeit did not increase, over three years. • Wind speed, salinity and river discharge volume influenced plastic contamination. • Long-term monitoring of marine plastics and physicochemical parameters is essential. [ABSTRACT FROM AUTHOR]

For the first time, a quantitative assessment of this pollutant was made at the bottom of the rivers of the Mekong basin, and the features of its accumulation and dynamics in bottom sediments and relationship with abundance of fish and decapods were investigated. Sampling of materials for the research was carried out by bottom trawls in the Mekong delta in Vietnam. The amount of macroplastic caught by the trawl from the bottom averaged 33.4 g/100 m2. The maximum values of the waste content (up to 923.2 g/100 m2) were confined to the districts of large cities. The distribution of macroplastic was characterized by high spatio-temporal variability. Its amount was significantly (p < 0.05) higher in branches with low monthly flow, in shallow-water areas, as well as in the low-water period. During the flood period, which usually lasts from July to November, the amount of macroplastic at the bottom decreased by an average of 2.5 times. In this study a significant relationship between the number of animals and the mass of macroplastics was statistically proven for most species of fish and decapods. The substrate, containing a significant amount of plastic fragments, attracted aquatic organisms. All in all, we present results for poorly understood processes of transport, deposition and influence of plastic debris in large rivers in regions of monsoon subequatorial climate and show that more efforts should be dedicated to further unravel potentially complex pathways of the plastic exposure to water ecosystems. [Display omitted] • Macroplastic is retained in significant quantities in bottom sediments of the Mekong. • Deposition of macroplastic occurs more intensively during the low-water period. • The construction of dams is conducive to the deposition of plastic at the bottom. • Macroplastic attracts fish and decapods, which changes their behavior. [ABSTRACT FROM AUTHOR]

[Display omitted] • Linking observed entanglement prevalence to plastic debris exposure in SSD-approach. • Quantifying a spatially-explicit indicator of potential entanglement impacts. • Presenting application options for life cycle and risk assessments. Marine animals have been known to interact with and become entangled in plastic debris for decades. Despite increasing annual input volumes of plastic waste to the natural environment and the threat this constitutes to marine biodiversity, impacts of mismanaged plastic waste generally remain unquantified in environmental impact assessments. In this paper, we develop a Species Sensitivity Distribution (SSD) approach for estimating a spatially differentiated indicator of potential macroplastic entanglement impacts with global coverage of the world's oceans. This constitutes a key modelling step that contributes towards the inclusion of plastic litter effects in impact assessments. We gathered entanglement incidence data for 20 species of marine mammals, turtles and birds from different populations and marine regions. To capture species-specific sensitivities to entanglement and spatially varying concentrations of plastic debris, concentration–response modelling of field data was used to develop the SSD-based model. This was achieved by linking population specific entanglement records to corresponding regional areas of exposure and an existing global model of plastic debris concentrations. The SSD was further applied to derive an estimate of the Potentially Affected Fraction (PAF) of species on a global scale, highlighting regional hotspots of potential entanglement impacts at current levels of marine plastic pollution. This indicator can be adapted and applied in impact assessments in order to account for potential impacts of mismanaged plastic waste ending up in marine ecosystems. [ABSTRACT FROM AUTHOR]

Plastic in the environment is considered an emerging pollutant of global concern. In spite of intensive research, many questions remain open, such as the processes that drive the deposition and remobilization of plastic debris on river beaches. The objectives of this study were: i) to analyze the influence of the natural hydrological fluctuations and wind intensity on the distribution of mesoplastic (0.5–2.5 cm) and macroplastic (>2.5 cm) debris in beach sediments of a large river, ii) to describe the type of plastic debris found and iii) to explore potential relations between the number of items and weight of macro- and mesoplastics. Our results suggest that, during lowering water levels, flow removes the plastic debris and transports it further downstream. Conversely, when the beach sediments remain exposed during long periods, the plastic debris accumulates considerably. Nevertheless, the influence of wind intensity on plastic debris transport was comparatively negligible. In other words, in our study the water flow had a greater capacity to remobilize and transport plastic debris than the wind. The most abundant mesoplastic items were foam, hard plastic, film and small fragments of fishing line. The dominant macroplastic items recorded were pieces of fishing line (nylon) and cigarette filters (cellulose acetate), typically discarded by beach users. Other items found in large quantities were soft packaging elements (expanded polystyrene), hard plastic containers (polystyrene, polyethylene terephthalate) and beverage bottles (polyethylene terephthalate), typical items of domestic use in the Paraná River region. Finally, we found that the density of macroplastic items is highly correlated to the density of mesoplastic items, serving as surrogate for further estimations. Our results could help to develop better mitigation strategies in seasonal riverscapes, based on the influence of the hydrological cycle and the characteristics of the most abundant meso- and macroplastics. [Display omitted] • Hydrology plays a crucial role in the dynamics of plastic debris on river beaches. • The influence of wind intensity on plastic debris dynamics was minor. • Plastic debris tend to accumulate on river beaches during long periods of sediment exposition. • The dominant macroplastics were fishing lines, cigarette butts, packaging and bottles. • The density of macroplastic items can be used as surrogate for density of mesoplastic. [ABSTRACT FROM AUTHOR]

• A complete mass balance for plastics in a wastewater treatment plant was established. • Plastics of all sizes down to 10 µm were identified in screening material, influent, digested sludge, and effluent using µFTIR imaging. • The removal efficiency was >98.8% for small microplastics <500 µm and were mostly (65.8%) retained in the sludge. • For all plastics entering the plant, the removal efficiency was 99.6 % and were largely (73.4%) retained in the screenings. • More than five times the mass of plastic found in the sludge were identified in screening materials. A complete plastic particle mass balance was established at Sweden's second-largest wastewater treatment plant. It comprised material collected at its two bar screens, a 20 mm and a 2 mm one, in the influent water after the 20 mm screen, the effluent water, and the digested sludge. Macro- and microplastics above 500 µm were analysed individually applying ATR-FTIR, while microplastics of 10–500 µm were analysed by µFTIR imaging with automated particle recognition. Masses of plastics >500 µm were determined by weighting, while the mass of the smaller microplastics was estimated from the imaging. The total plastic load on the plant was 202.2 kg d−1, of which the two screens retained 73%. The remaining plastic mass was found in the sludge (13.6%) and the effluent (0.4%). The missing 12.7% could be caused by sampling and measuring uncertainties and potentially also fragmentation below the size detection limit of the analytical approach, or by degradation. The bar screens furthermore retained plastics smaller than the screen size, indicating that this material should be taken into account also when solely looking at smaller particles. The overall treatment efficiency of the plant was high: 99.6% considering both macro- and microplastics, and 98.8% considering only microplastics <500 µm. [ABSTRACT FROM AUTHOR]

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. [Display omitted] • First study on marine plastic litter in Palawan, Philippines • Sites on the east coast have three times more plastics than the west coast. • Collected plastics were mostly fishing line nylon, food packaging and plastic fragments. • Seventy six percent of the sites can be categorized as dirty and extremely dirty. [ABSTRACT FROM AUTHOR]

Plastics can enter biogeochemical cycles and thus be found in most ecosystems. Most studies emphasize plastic pollution in oceanic ecosystems even though rivers and estuaries are acknowledged as the main sources of plastics to the oceans. This review detected few studies approaching the transboundary issue, as well as patterns of estuarine gradients in predicting plastic distribution and accumulation in water, sediments, and organisms. Quantities of plastics in estuaries reach up to 45,500 items m−3 in water, 567,000 items m−3 in sediment, and 131 items per individual in the biota. The role of rivers and estuaries in the transport of plastics to the ocean is far from fully understood due to small sample sizes, short-term approaches, sampling techniques that underestimate small plastics, and the use of site-specific sampling rather than covering environmental gradients. Microfibres are the most commonly found plastic type in all environmental matrices but efforts to re-calculate pathways using novel sampling techniques and estimates are incipient. Microplastic availability to estuarine organisms and rising/sinking is determined by polymer characteristics and spatio-temporal fluctuations in physicochemical, biological, and mineralogical factors. Key processes governing plastic contamination along estuarine trophic webs remain unclear, as most studies used "species" as an ecological unit rather than trophic/functional guilds and ontogenetic shifts in feeding behaviour to understand communities and intraspecific relationships, respectively. Efforts to understand contamination at the tissue level and the contribution of biofouling organisms as vectors of contaminants onto plastic surfaces are increasing. In conclusion, rivers and estuaries still require attention with regards to accurate sampling and conclusions. Multivariate analysis and robust models are necessary to predict the fate of micro- and macroplastics in estuarine environments; and the inclusion of the socio-economic aspects in modelling techniques seems to be relevant regarding management approaches. [Display omitted] • Environmental gradients play a major role in the fate of estuarine plastics. • Methods used to investigate microplastics and plankton should be different. • Robust sampling is necessary to help develop the "source-to-sea" approach. • Recent estimations of microplastic export are higher by 3 orders of magnitude. • Research of interactions between chemicals and the Plastisphere lack in estuaries. Main finding: Investigation of the river-estuary-ocean continuum and its specificities is crucial to fully elucidate plastic contamination in aquatic environments. [ABSTRACT FROM AUTHOR]

We present reflectance measurements collected from virgin and ocean-harvested plastics. Virgin plastics included high and low density polyethylene (HDPE, LDPE), polypropylene (PP) as well as polystyrene (PS). Ocean-harvested plastics were ropes, sheets, foam, pellets and fragmented items previously trawled from the North Pacific Garbage Patch. Nadir viewing angles and plastic pixel coverage were varied to advance our understanding of how reflectance shape and magnitude can be influenced by these parameters. We also investigated the effect of apparent colour of plastics on the measured reflectance from the ultraviolet (UV - 350 nm), visible, near to shortwave infrared (NIR, SWIR - 2500 nm). Statistical analyses indicated that the spectral reflectance of the plastics was significantly correlated to the percentage pixel coverage. There was no clear relationship between the reflectance observed and the viewing nadir angle but dampened materials seemed to be more isotropic (near-Lambertian) than their dry counterparts. A loss in reflectance was also determined between dry and wet plastics. Location of absorption features was not affected by the apparent colour of objects. In general, ocean-harvested plastics shared more identical absorption features (~960, 1215, 1440, 1732, 1920 nm) and had lower reflectance intensity compared to the virgin plastics (~980 nm). Prospects for satellite retrieval of plastic type and pixel plastic coverage are discussed based on Top-of-Atmosphere (TOA) signal simulated through radiative transfer computation using the documented plastic reflectances. Non-linear relationships between TOA reflectance and plastic coverage were observed depending on wavelength and plastic type. Most of the plastics analysed impact significantly the TOA signal but two plastic types did not produce strong signal at TOA (hard fragments, LDPE). Nevertheless, all plastic types produced detectable signals when observations were simulated within the sunglint direction. The measurements collected in this study are an extension to available high quality spectral reference libraries and can support further research in developing remote sensing algorithms for marine litter. ga1 • Showcase remote sensing as complementary plastic litter monitoring strategy. • Present hyperspectral measurements of virgin and ocean plastics from UV to SWIR. • Explore anisotropic reflectance properties of plastics at varying pixel coverages. • Show the apparent colour of plastics affects UV to SWIR spectral shape and magnitude. • Assess satellite remote sensing of plastics using radiative transfer solutions. [ABSTRACT FROM AUTHOR]

Marine litter affects various habitats across the world. This review focuses on the Adriatic region, considering the presence of marine litter as well as microplastics (mPs) and macroplastics (MPs) in different environments (water, beach, seabed and biota). Data from 53 scientific papers were critically analysed, providing a snapshot of this type of contamination, and evidencing critical issues. The final part of the review provides considerations on spatial and temporal trends, comparing data with the available information provided by transport forecasting models. It emerges that the most investigated areas are those most subjected to the contribution of rivers, tourism or have the greatest relevance to nature conservation. Our analysis also reveals that, even though many international research projects have played a fundamental role in the creation of shared methods and protocols, currently available data are difficult to compare. Nevertheless, our results enhance knowledge of the state of the art in the research carried out so far, and on the situation regarding pollution due to the marine litter in the Adriatic Sea, as well as highlighting avenues for future investigation. Image 1 • The studies on the presence of marine litter in the Adriatic region are collected. • Plastic has been found in sea water, sea bed, beaches and biota. • Polyolefin is the main type of plastic found in the investigated environments. • Comparison and monitoring data is difficult when uniform protocols are not adopted. • The available protocols should be improved to obtain more representative data. All the main studies on the presence of marine litter in the Adriatic region are analysed, finding that different protocols were used, and highlighting the different types of plastic present in seawater, sea bed, beaches and biota. [ABSTRACT FROM AUTHOR]

Reducing plastic pollution in rivers, lakes, and oceans is beneficial to aquatic animals and human livelihood. To achieve this, reliable observations of the abundance, spatiotemporal variation, and composition of plastics in aquatic ecosystems are crucial. Current efforts mainly focus on collecting data on the open ocean, on beaches and coastlines, and in river systems. Urban areas are the main source of plastic leakage into the natural environment, yet data on plastic pollution in urban water systems are scarce. In this paper, we present a simple method for plastic hotspot mapping in urban water systems. Through visual observations, macroplastic abundance and polymer categories are determined. Due to its simplicity, this method is suitable for citizen science data collection. A first application in the Dutch cities of Leiden and Wageningen showed similar mean plastic densities (111–133 items/km canal) and composition (75–80% soft plastics), but different spatial distributions. These observations emphasize the importance of long-term data collection to further understand and quantify spatiotemporal variations of plastics in urban water systems. In turn, this will support improved estimates of the contribution of urban areas to the plastic pollution of rivers and oceans. [ABSTRACT FROM AUTHOR]

Plastic debris presents a serious hazard to marine ecosystems worldwide. In this study, we developed a method to evaluate high-resolution maps of plastic emissions from the land into the sea offshore of Japan without using mismanaged plastic waste. Plastics were divided into microplastics (MicPs) and macroplastics (MacPs), and correlations between the observed MicP concentrations in rivers and basin characteristics, such as the urban area ratio and population density, were used to evaluate nationwide MicP concentration maps. A simple water balance analysis was used to calculate the annual outflow for each 1 km mesh to obtain the final MicP emissions, and the MacP input was evaluated based on the MicP emissions and the ratio of MacP/MicP obtained according to previous studies. Concentration data revealed that the MicP concentrations and basin characteristics were significantly and positively correlated. Water balance analyses demonstrated that our methods performed well for evaluating the annual flow rate, while reducing the computational load. The total plastic input (MicP + MacP) was widely distributed from 210–4776 t/yr and a map showed that plastic emissions were high for densely populated and highly urbanized areas in the Tokyo metropolitan area, as well as other large urban areas, especially Nagoya and Osaka. These results provide important insights that may be used to develop countermeasures against plastic pollution and the methods employed herein can also be used to evaluate plastic emissions in other regions. [ABSTRACT FROM AUTHOR]

Plastic pollution has been reported in sediment, surface water and biota of freshwater systems especially in Europe, North and South America, and Asia with limited studies focussing on African great lakes. This study therefore investigated the occurrence, abundance and distribution of micro-, meso- and macro-plastic debris along shores and sediment of northern Lake Victoria. The abundance of micro-, meso- and macro-plastics measured as particles/kg dry sediment were in range of 0–1102, 0–218 and 0–100 respectively in shoreline sediment and 0–108, 0–33 and 0–77 respectively in lake sediment. The mean abundance of micro-, meso- and macro-plastic debris at fish landing beaches (75.2 ± 50.0, 16.7 ± 8.1 and 18.1 ± 4.6 respectively) were higher than what was recorded at recreational beaches (1.5 ± 0.6, 3.1 ± 3.1 and 3.8 ± 3.8 respectively). Similarly, mean abundance of micro-, meso- and macro-plastic debris in lake sediment were higher in areas of fish landing beaches (9.5 ± 2.6, 2.1 ± 1.5 and 7.7 ± 4.5 respectively) than what was recorded in areas of recreational beaches (0.7 ± 0.7, 0.2 ± 0.1, and 0 ± 0 respectively). Films, filaments, fragments, foam and pellets were the plastic types, with the shoreline sediment dominated by films (>54%) while lake sediment was dominated by filaments (>55%), across size groups (micro-, meso- and macro-plastics). Spearman's rank correlation indicated strong and significant correlation between abundance of micro- and meso-plastics for total plastic, film plastic and fragment plastic in shoreline sediment. Significant correlation between macroplastics in shoreline sediment and microplastics in lake sediment for total plastics was observed. The FTIR analysis revealed that polyethylene, polypropylene, Polyethylene Terephthalate, Polyamide (nylon), and polyvinyl chloride were the major polymers. These results demonstrated that fish landing beaches along Lake Victoria are hotspot areas for plastic pollution of the lake and should therefore be targeted for management of plastic pollution of Lake Victoria. Image 1 • Plastic pollution of shores and sediment of Lake Victoria in East Africa was studied. • Abundance of plastic debris was highest at fish landing beaches and lowest at recreational beaches. • In most sites, microplastic abundance decreased with increasing distance from the shoreline into pelagic waters. • Film plastic type was dominant in shoreline sediment while filament type dominated in lake sediment. • There was a strong correlation between microplastics and mesoplastics in shoreline sediment. [ABSTRACT FROM AUTHOR]

Plastic pollution in aquatic ecosystems is an emerging environmental risk, as it may negatively impacts ecology, endangers aquatic species, and causes economic damage. Rivers are known to play a crucial role in transporting land‐based plastic waste to the world's oceans, but riverine ecosystems are also directly affected by plastic pollution. To better quantify global plastic pollution transport and to effectively reduce sources and risks, a thorough understanding of origin, transport, fate, and effects of riverine plastic debris is crucial. In this overview paper, we discuss the current scientific state on plastic debris in rivers and evaluate existing knowledge gaps. We present a brief background of plastics, polymer types typically found in rivers, and the risk posed to aquatic ecosystems. Additionally, we elaborate on the origin and fate of riverine plastics, including processes and factors influencing plastic debris transport and its spatiotemporal variation. We present an overview of monitoring and modeling efforts to characterize riverine plastic transport, and give examples of typical values from around the world. Finally, we present an outlook to riverine plastic research. With this paper, we aim to present an inclusive and comprehensive overview of riverine plastic debris research to date and suggest multiple ways forward for future research. This article is categorized under: Science of Water > Water QualityWater and Life > Stresses and Pressures on Ecosystems [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the amount, composition and origin of plastic debris in one of the world largest river, the Paraná River in Argentina (South America), focusing on the impact of urban rivers, relationships among macro, meso and microplastic, socio-political issues and microplastic ingestion by fish. We recorded a huge concentration of macroplastic debris of domestic origin (up to 5.05 macroplastic items per m2) dominated largely by bags (mainly high- and low-density polyethylene), foodwrapper (polypropylene and polystyrene), foam plastics (expanded polystyrene) and beverage bottles (polyethylene terephthalate), particularly downstream from the confluence with an urban stream. This suggests inadequate waste collection, processing and final disposal in the region, which is regrettably recurrent in many cities of the Global South and Argentina in particular. We found an average of 4654 microplastic fragments m−2 in shoreline sediments of the river, ranging from 131 to 12687 microplastics m−2. In contrast to other studies from industrialized countries from Europe and North America, secondary microplastics (resulting from comminution of larger particles) were more abundant than primary ones (microbeads to cosmetics or pellets to the industry). This could be explained by differences in consumer habits and industrialization level between societies and economies. Microplastic particles (mostly fibres) were recorded in the digestive tract of 100% of the studied Prochilodus lineatus (commercial species). Contrary to recently published statements by other researchers, our results suggest neither macroplastic nor mesoplastics would serve as surrogate for microplastic items in pollution surveys, suggesting the need to consider all three size categories. The massive plastic pollution found in the Paraná River is caused by an inadequate waste management. New actions are required to properly manage waste from its inception to its final disposal. Image 1 • Plastic pollution in a South American mega-river was studied. • Pollution is mainly caused by the inadequate waste management, frequent in the Global South. • Further research must not overlook macroplastics in this geopolitical region. • Secondary microplastics were more abundant than primary ones. • Microplastics were recorded in all the fish individual studied. Massive plastic pollution in a mega-river from Argentina, mainly caused by inadequate waste management. [ABSTRACT FROM AUTHOR]

In recent years, there is great concern about plastic pollution due to the identification of several environmental risks associated with microplastics (<5 mm). This study investigated microplastic and macroplastic accumulation patterns in a newly formed Spartina alterniflora colonized saltmarsh of an estuary in southeastern China. Abundance of microplastic and macroplastic particles was in the range of 9600–130725 and 200-4350 n/m2, respectively. Abundances of microplastics and macroplastics were highest at the saltmarsh edge, but the mass of macroplastics was highest in the saltmarsh interior. Mass of microplastics and macroplastics in bareflats was significantly lower than vegetated areas. Although microplastics accounted for 96.3% of total plastic abundance, macroplastics accounted for 90% of total plastic mass. Results showed that S. alterniflora dominated saltmarshes have a strong ability to trap plastic debris, especially macroplastics. Thus, coastal saltmarshes may serve as a transformer of macroplastics to microplastics and consequently as a source of microplastics to the ocean. Image 1 • Saltmarshes have a strong ability to trap plastic debris, especially macroplastics. • Reporting the mass of plastics is important for plastic pollution monitoring. • Degradation of macroplastics in saltmarshes may produce abundant microplastics. • Saltmarshes act as a sink for macroplastics and a source of microplastics to ocean. • Macroplastic removal from beaches is critical for reducing microplastic pollution. [ABSTRACT FROM AUTHOR]

Plastic pollution is one of the most acute environmental topics of our time. While there is a great scientific effort to tackle this problem, it has not always been well-coordinated or properly targeted. In this short review, we call for scientists to get involved in three crucial topics (threats) underestimated—or ignored—in freshwater systems: (i) plastic-species entanglement, (ii) plastic as nesting material, and (iii) macroplastic debris coming from mismanaged household solid waste. Reducing the knowledge gaps between marine and freshwater environments will be crucial to solute the plastic pollution problem effectively and globally. Therefore, we make a plea here to reinforce research activities on these three issues in freshwater environments worldwide. [ABSTRACT FROM AUTHOR]