Microplastic and artificial cellulose microfibers ingestion by reef fishes in the Guarapari Islands, southwestern Atlantic

Microplastic abundance and characteristics in bivalves from Tam Giang-Cau Hai and O Loan Lagoons, coastal regions in Central Vietnam: Implication on human health

Four common bivalves, including white clam (Meretrix lusoria), lined clam (Paratapes undulatus), oysters (Crassostrea gigas), and green mussels (Perna viridi), which are commonly consumed in Central Vietnam, were collected from Tam Giang-Cau Hai and O Loan Coastal Lagoons. The samples were investigated for the presence of microplastics (MPs) in their tissues. The average number of MPs determined in white clams, lined clams, oysters, and green mussels in Central Vietnam varies from 0.3 to 0.9 per g-ww and from 0.9 to 5.6 per individual. Fibers, fragments, and pellets were found with various proportions concerning. Fibers were the most common shape, making up 36-74 % of the total microplastics, followed by fragments accounting for 16-47 %. The most prevalent colors were white-transparent and black-grey, comprising 49-81 % of the MPs. Regarding the microplastics found in the bivalve tissues, 78-80 % were <500 μm. Given chemical analysis, rayon accounted for 38 % of the microplastics discovered in bivalve tissues; closely PET (13 %), PA (10 %), and PP (10 %) were followed. This study offers valuable insights into the microplastic contamination concerned by bivalve consumption in Thua Thien Hue and Phu Yen, Central Vietnam; the results estimate the annual intakes are between 5000 and 10,000 particles per person. Unprecedentedly addressed in the literature, these findings contribute to a better understanding of microplastic pollution in Vietnam. The results altogether provide solid shreds of evidence for the MP contamination in Vietnam-based seafood, thus encouraging further attempts for plausible socio-economical regulations and raising public awareness on the issue.

Microscopic anthropogenic waste ingestion by small terrestrial European passerines: evidence from finch and tit families

Microscopic anthropogenic waste (MAW) has become a major environmental concern worldwide. Our study aimed to assess the accumulation of MAW in the gastrointestinal tracts of nine common European passerine species from finch (Fringillidae) and tit (Paridae) families, and evaluate their suitability for environmental monitoring. We searched for MAW in the birds' stomachs and intestines and identified suspected particles using Raman microspectroscopy. In total, we found 57 MAW particles in 31 out of 149 analyzed individuals, 7 of which were microplastics (polyethylene, polyethylene terephthalate, polystyrene), 1 was identified as carbon nanotube, while 49 were cellulosic-based (cotton, cellulose, rayon, viscose). The generalized linear mixed models identified bird family and time in season as significant predictors of MAW ingestion. Finches ingested more MAW than tits, and higher ingestion rates were observed during the non-breeding period. Other predictors, including bird sex, age, gastrointestinal tract section, and site, showed varying but non-significant effects. As predicted, the studied species exhibited a lower ingestion rate of MAW compared to terrestrial birds studied so far, possibly due to their diet and feeding behavior. Given that these species are prey for many avian and non-avian predators, they may contribute to the transfer of MAW to higher trophic levels.

Balancing biomonitoring and conservation: A non-lethal method to extract microplastics from the sea anemone Bunodosoma cangicum

The sea anemone Bunodosoma cangicum is a potential biomonitor species of microplastic (MP) contamination. However, current MP extraction methods for this species, and most organisms, are lethal to the specimens. This poses the risk of negatively impact on local populations, which are already under considerable anthropogenic pressures. Therefore, this study aimed to evaluate a non-lethal method to extract MPs from the gastrovascular cavity of B. cangicum. The method consists of inducing egestion by pressing the anemone's central column with the aid of a stainless-steel instrument. The proposed technique was applied to 40 anemones sampled in the intertidal zone of a marine beach on the Brazilian Amazon coast. The recovered particles were characterized by Focal Plane Array Fourier Transform Infrared (FPA-FTIR) microscopy. The MP content obtained by the non-lethal method was then compared with that obtained by the lethal techniques applied previously at the same site. An additional 30 anemones from the same area were used in laboratory experiments to evaluate the method's effects on growth, survival, and predatory performance. The non-lethal method retrieved quantities, sizes and shapes of MPs similar to those recovered by dissection techniques. Furthermore, the exposure to the method had no significant effects on the organism's growth, survival and predatory performance. Therefore, the non-lethal method proved to be efficient in extracting MPs from the gastrovascular cavity of B. cangicum without causing deleterious effects. Thus, the proposed method enhances the species' potential as a biomonitor, as it easily allows numerous organisms to be adequately sampled without sacrificing them. CAPSULE: The non-lethal method proved to be efficient in extracting MPs from the gastrovascular cavity of B. cangicum without causing deleterious effects.

Natural and Regenerated Cellulosic Microfibers Dominate Anthropogenic Particles Ingested by Commercial Fish Species from the Adriatic Sea

This study investigated the occurrence of fibrous microplastics and natural and artificial cellulose microfibers in the gastrointestinal tracts of Mullus barbatus and Merluccius merluccius specimens from the Adriatic Sea (Central Mediterranean), an important hotspot for marine litter accumulation. Red mullet and European hake were chosen due to their roles as bioindicators of marine pollution in the Mediterranean, and their economic relevance as fishery resources. Microfibers were found in 72% of M. barbatus and 68% of M. merluccius, at levels ranging from 1 to 67 particles/individual. Most of the microfibers extracted were textile fibers that were blue (33.6%), clear (26.1%), and black (20.3%) in color, while the length distribution showed the prevalence of microfibers in the size range of 350-950 µm. This visual identification, corroborated by the micro-FTIR analysis of a sub-sample of microfibers, revealed that natural and artificial cellulose microfibers were more common (80%) than fibrous microplastics. The results confirmed that both of these fish species are susceptible to microfiber ingestion and indicated the high availability of natural and artificial cellulosic fibers in the Adriatic Basin. Despite the increased evidence of microfiber pollution in the marine ecosystem, only a limited number of studies examine natural/artificial microfiber contamination and ingestion by marine biota. Therefore, greater attention should be given to this new type of contaminant, considering its implications in terms of environmental health, food security, and food safety.

Toxic tuna tales: Tracing microplastic pathways in mackerel tuna (Euthynnus affinis), longtail tuna (Thunnus tonggol), and bullet tuna (Auxis rochei)

Casting a shadow upon marine ecosystems worldwide, microplastic pollution emerges as a formidable threat, yet its repercussions on commercially significant marine fish remain largely unexplored. This investigation delves into the realm of microplastic contamination within three tuna species (Euthynnus affinis, Thunnus tonggol, and Auxis rochei) inhabiting Malaysian waters, with a keen focus on the gastrointestinal tract (GIT), gills, and edible muscle. These species were chosen due to their significant ecological roles and considerable commercial value, being extensively fished and widely consumed across global regions. Scrutinising 125 tuna specimens uncovers a spectrum of contamination levels across species, with T. tonggol registering the highest concentration (1.22 ± 0.14 microplastics per gram). Remarkably, male tunas exhibit a discernible proclivity towards heightened microplastic accumulation relative to their female counterparts. Noteworthy morphotypes of microplastics predominantly encompass fibres (92.43 %), notably manifesting in black hues (63.25 %). Notably, microplastics spanning the 0.01-1.00 mm size range assert their dominance, constituting a substantial 61.54 % of the total, with rayon emerging as the leading polymer (54.39 %). These findings highlight the pivotal role of the GIT and gills as primary sites of microplastic accumulation in tuna, raising concerns about potential human health implications through seafood consumption. It is crucial to deepen our understanding of microplastic distribution and characteristics in seafood to develop effective mitigation strategies and safeguard human well-being within marine environments. This study advocates for urgent global attention to address the ecological and human health impacts of microplastic contamination in marine ecosystems.

Low incidence of microplastics in coral reefs of Kāne'ohe Bay, Hawai'i, USA

This study investigated microplastic and other micro-debris pollution in sediment, seawater, sea cucumbers, and corals from fringing and patch reefs in Kāne'ohe Bay, O'ahu, Hawai'i, USA. Microplastic pollution in Kāne'ohe Bay Bay was low compared to other tropical coral reefs. Microplastics were detected in sediments (29 %), sea cucumbers (9 %), and coral (0-2 %) samples but were not quantifiable. Seawater had quantifiable microplastic (< 0.5 mm) and macroplastic (> 0.5 mm) pollution, with mean concentrations ranging from 0.0061 to 0.081 particles m-3. Most particles detected in seawater samples were larger, floating plastic debris consisting mostly of polyethylene, polypropylene fragments, and fibers. Across the other matrices, the most detected particles were polyester, polypropylene, and cotton fibers. These results provide baseline data for this important coral reef ecosystem, and further monitoring is recommended to understand the seasonal and long-term trends in microplastic pollution and its potential future impacts.

First evidence of microplastics and their characterization in yellow-legged gull (Larus michahellis michahellis, Naumann, 1840) pellets collected from the Sfax salina, southeastern Tunisia

The aim of this work was to provide evidence on the presence of microplastics (MPs) in regurgitated Yellow-legged Gull pellets (n = 18) from Sfax salina (south-eastern Tunisia). This artificial area is subject to high anthropogenic pressure and hosts Yellow-legged Gulls, which are at the top of the trophic chain and can be used as sentinel species to monitor litter in the environment, including plastic pollution. The total number of MPs found in the samples was 309, 63.8 % fibres (4.95 ± 3.51 MPs/g) and 36.2 % fragments (2.87 ± 1.74 MPs/g). Micro-FTIR analysis evidenced that a large proportion of the fibres was attributed to artificial cellulose (40.7 %). Ethylene vinyl acetate (EVA) and polyethylene (PE) were found in the fragments.

First report of plastic and non-plastic microparticles in stomach of slandertail lanternshark and shortspine spurdog from the edge of East China Sea

This study investigates the presence of plastic and non-plastic microparticles in the gastrointestinal tracts of two deep-sea sharks, Etmopterus molleri (n = 118) and Squalus mitsukurii (n = 6), bycatch from the East China Sea continental shelf. We found a total of 117 microparticles, predominantly fibres (67.52 %), with blue (31.62 %) and black (23.94 %) being the most prevalent colours. E. molleri contained 70 microparticles (0.63 ± 0.93 items/shark), 61.42 % non-plastics like viscose and cotton, while plastics included polyethylene, polyethylene terephthalate, and acrylic. Despite S. mitsukurii's limited sample size, the results show that it takes in a lot of microparticles (47 microparticles, 7.83 ± 2.64 items/shark), 57.44 % non-plastics (viscose, cotton, and ethyl cellulose), and 42.56 % plastics. A positive correlation between microparticle presence and total length was observed for E. molleri. These results provide initial data on microparticle ingestion by these species, highlighting potential ecological risks and trophic transfer implications in deep-sea ecosystems.

Like noodles in a soup: Anthropogenic microfibers are being ingested by juvenile fish in nursery grounds of the Southwestern Atlantic Ocean

The balance between marine health and ecosystem sustainability confronts a pressing threat from anthropogenic pollution. Estuaries are particularly susceptible to contamination, notably by anthropogenic microfibers originated from daily human activities in land and in fishing practices. This study examines the impact of anthropogenic microfibers on the whitemouth croaker in an estuarine environment of the Southwestern Atlantic Ocean during cold and warm seasons. The presence of anthropogenic microfibers was revealed in 64 % of juvenile gastrointestinal tracts, and 94 % of water samples, and concentrations were influenced by factors such as temperature, bay zone, and fish body length. Blue and black anthropogenic microfibers, with a rather new physical aspect, were dominant. This study highlights the impact of microfibers in a heavily anthropized body of water, subject to federal and local regulations due to the presence of commercially significant fish species inhabiting this area.

Microplastics and other anthropogenic fibres in large apex shark species: Abundance, characteristics, and recommendations for future research

Microplastics and microfibres are found ubiquitously in global oceans as well as marine organisms from different trophic levels. However, little is known about the presence of microplastics and microfibres in marine megafauna, such as sharks. This study provided the first investigation of the presence of microplastics and other anthropogenic fibres (i.e., cellulose based fibres) in intestine and muscle samples of four large apex shark species in Australian coastal waters. Microplastics and other anthropogenic fibres were found in 82% of the analysed intestine samples. The mean abundance in intestine samples was 3.1 ± 2.6 particles/individual, which corresponded to 0.03 ± 0.02 particles/g of intestine, across all shark species. The size of particles ranged from 190 to 4860 μm in length with 92% being fibrous in shape and the rest fragments. FTIR spectroscopy identified that 70% of fibres were cellulose-based followed by polyethylene terephthalate (PET), while the fragments were polyethylene and polypropylene. In shark muscles, 60% of samples contained microplastics and other anthropogenic fibres, again with the majority being cellulose-based fibres followed by PET fibres. Methodological differences hinder a more comprehensive assessment of microplastic contamination across studies. Additionally, we identified some challenges which should be factored in for future studies looking at the presence of microplastics as well as other anthropogenic fibres in these large marine organisms. Overall, the findings provide first evidence of microplastics and other anthropogenic fibres not only in the intestines, but also in muscle tissues of large apex shark species.

Impacts of microplastic on fisheries and seafood security - Global analysis and synthesis

This review paper collected, collated, analysed, interpreted, synthesised, and documented the research investigations conducted on microplastic (MPs) pollution impacts on seafood organisms (including fish, sharks, shrimps, lobsters, crabs, oysters, mussels, and seaweeds) during the last ten years (2012-2022) covering fifty-seven locations/countries in the world. MPs contaminated 926 seafood species comprising 895 finfish, 09 crustaceans, 20 molluscs and 02 seaweeds. Seafood from Asia was found to be most contaminated with MPs. High MP contamination/ingestion was revealed in several seafood organisms. The ingestion of MPs can reduce fish growth and fish fitness, leading to reduced yield/fish production. Fish and seafood play a significant role in supporting the economy, employment, food sources, and livelihoods of people across the globe, which can be threatened due to the contamination of seafood organisms with MPs. MPs have bioaccumulated in fish skin, gills, stomachs, liver, intestine, and muscles as well as dry fish and canned fish. Hence, the consumption of MP-contaminated fresh fish, whole fish, dried fish or canned fish poses risks as it may be a pathway of MP transfer to humans. MPs can increase the health risks to seafood fish consumers since there is a probability that high risks pollutants adsorbed on MPs (heavy metals, pesticides, and oil compounds) can transfer to humans via the food chain. Several of the chemicals (heavy metals, DDT, PAHs) adsorbed onto MPs are carcinogenic. MPs have also been detected in fish meals, therefore, farmed livestock such as aquaculture fish and chicken fed to fish meals can be exposed to MPs and ultimately to humans. Preventive and safety measures are suggested to reduce the exposure of MPs to humans. In addition, several policy strategies are recommended to reduce the impacts of plastic waste and plastic pollution on the environment, aquatic biota, wildlife, seafood and human health.

Removal of organic and inorganic contaminants from the air, soil, and water by algae

Rapid increases in human populations and development has led to a significant exploitation of natural resources around the world. On the other hand, humans have come to terms with the consequences of their past mistakes and started to address current and future resource utilization challenges. Today's primary challenge is figuring out and implementing eco-friendly, inexpensive, and innovative solutions for conservation issues such as environmental pollution, carbon neutrality, and manufacturing effluent/wastewater treatment, along with xenobiotic contamination of the natural ecosystem. One of the most promising approaches to reduce the environmental contamination load is the utilization of algae for bioremediation. Owing to their significant biosorption capacity to deactivate hazardous chemicals, macro-/microalgae are among the primary microorganisms that can be utilized for phytoremediation as a safe method for curtailing environmental pollution. In recent years, the use of algae to overcome environmental problems has advanced technologically, such as through synthetic biology and high-throughput phenomics, which is increasing the likelihood of attaining sustainability. As the research progresses, there is a promise for a greener future and the preservation of healthy ecosystems by using algae. They might act as a valuable tool in creating new products.

Sources, Degradation, Ingestion and Effects of Microplastics on Humans: A Review

Celluloid, the predecessor to plastic, was synthesized in 1869, and due to technological advancements, plastic products appear to be ubiquitous in daily life. The massive production, rampant usage, and inadequate disposal of plastic products have led to severe environmental pollution. Consequently, reducing the employment of plastic has emerged as a pressing concern for governments globally. This review explores microplastics, including their origins, absorption, and harmful effects on the environment and humans. Several methods exist for breaking down plastics, including thermal, mechanical, light, catalytic, and biological processes. Despite these methods, microplastics (MPs, between 1 and 5 mm in size) continue to be produced during degradation. Acknowledging the significant threat that MPs pose to the environment and human health is imperative. This form of pollution is pervasive in the air and food and infiltrates our bodies through ingestion, inhalation, or skin contact. It is essential to assess the potential hazards that MPs can introduce. There is evidence suggesting that MPs may have negative impacts on different areas of human health. These include the respiratory, gastrointestinal, immune, nervous, and reproductive systems, the liver and organs, the skin, and even the placenta and placental barrier. It is encouraging to see that most of the countries have taken steps to regulate plastic particles. These measures aim to reduce plastic usage, which is essential today. At the same time, this review summarizes the degradation mechanism of plastics, their impact on human health, and plastic reduction policies worldwide. It provides valuable information for future research on MPs and regulatory development.

Occurrence and Characteristics of Microplastics in Wild and Farmed Shrimps Collected from Cau Hai Lagoon, Central Vietnam

This study investigated the occurrence of microplastics (MPs) in the gastrointestinal tracts (GT) and tissues of four common shrimps (including two wild-caught shrimps and two farmed shrimps) collected from a high-diversity lagoon in central Vietnam. The numbers of MP items in greasy-back shrimp (Metapenaeus ensis), green tiger shrimp (Penaeus semisulcatus), white-leg shrimp (Litopenaeus vannamei), and giant tiger shrimp (Penaeus monodon), determined per weight and individual, were 0.7 ± 0.3, 0.6 ± 0.2, 1.1 ± 0.4, and 0.5 ± 0.3 (items/g-ww), and 2.5 ± 0.5, 2.3 ± 0.7, 8.6 ± 3.5, 7.7 ± 3.5 (items/individual), respectively. The concentration of microplastics in the GT samples was significantly higher than that in the tissue samples (p < 0.05). The number of microplastics in the farmed shrimp (white-leg shrimp and black tiger shrimp) was statistically significantly higher than the number of microplastics in the wild-caught shrimp (greasy-back and green tiger shrimps) (p <0.05). Fibers and fragments were the dominant shapes of the MPs, followed by pellets, and these accounted for 42-69%, 22-57%, and 0-27% of the total microplastics, respectively. The chemical compositions determined using FTIR confirmed six polymers, in which rayon was the most abundant polymer, accounting for 61.9% of the MPs found, followed by polyamide (10.5%), PET (6.7%), polyethylene (5.7%), polyacrylic (5.8%), and polystyrene (3.8%). As the first investigation on the MPs in shrimps from Cau Hai Lagoon, central Vietnam, this study provides useful information on the occurrences and characteristics of the microplastics in the gastrointestinal tracts and tissues of four shrimp species that live in different living conditions.

Seasonal monitoring of microplastic pollution in the Southeast Black Sea: An example of red mullet (Mullus barbatus) gastrointestinal tracts

This study investigated seasonal presence of microplastic (MP) in gastrointestinal tracts of red mullet (Mullus barbatus) sampled from the Southeast Black Sea Region. A total of 335 MPs were detected in 120 individuals. While the most MP was observed in the winter and autumn seasons, quite few MPs were found in the summer and spring seasons. MP size did not show significant difference among seasons. While all of the MPs in the autumn and spring and most of the MPs in the winter were fiber-shaped, most of the MPs in the summer were fragments. The most observed MP color for all seasons was white. While polymer structures did not show much variation in spring and summer, six different polymers were determined for both autumn and winter. In general, less MPs were detected during fishing ban period (summer) and the characteristic properties of the detected MPs suggest a MP pollution in the region due to intense fishing activities.

Exploring microplastic contamination in reef-associated fishes of the Tropical Atlantic

Microplastics (MPs) are ubiquitous in marine compartments, and their transboundary distribution favours the dispersion and accumulation of particles in ecosystems. This study investigated MP contamination in four coastal fish species (Haemulon squamipinna, Chaetodon ocellatus, Syacium micrurum, and Alphestes afer) from the southwestern Tropical Atlantic. An alkaline treatment was applied to extract MPs from the digestive tracts, and a Laser Direct Infrared (LDIR) system was used to identify polymers. All species analysed were contaminated with MPs, with Alphestes afer being the most contaminated (1.45 ± 1.09 MPs individual^-1; frequency of occurrence 80 %). No significant differences were found in the number and size of detected particles among species. The most common shapes were fibres and films, and polyethylene was the most abundant polymer. This study provides important baseline data on MP contamination in coastal fish species inhabiting complex habitat areas relevant for conserving marine biodiversity.

Oysters and mussels as equivalent sentinels of microplastics and natural particles in coastal environments

Filter-feeder organisms such as oyster and mussels are exposed to particles like microplastics (MPs). Although widely used to monitor MPs contamination, little is known about their performance as sentinels, which are biological monitors accumulating contaminants without significant adverse effects. This study comparatively evaluated the quantitative and qualitative accumulation of MPs by oysters (Crassostrea brasiliana) and mussels (Perna perna) along a gradient of contamination in a highly urbanized estuarine system of Brazil. In the most contaminated site, both species presented the worst status of nutrition and health, and also one of the highest MPs levels reported for molluscs to date (up to 44.1 particles·g^-1). Despite some inter-specific differences, oysters and mussels were suitable and showed an equivalent performance as sentinels, reflecting the gradient condition demonstrated for other contaminants in the region. The similarity in MPs accumulation was also observed for qualitative aspects (polymer composition, sizes, shapes and colors). Particles were mostly <1000 μm, fibrous, colorless and composed by cellulose and polymethyl methacrylate (PMMA). Thus, despite small variations, the usage of C. brasiliana and P. perna is recommended and provides reliable information for environmental levels of microplastics.

Quantification and characterization of microplastics in surface water samples from the Northeast Atlantic Ocean using laser direct infrared imaging

15 filtration samples were collected at eight locations onboard the RV Sonne (cruise SO279 in 2020) from 6 m water depth using a fractionated stainless-steel filtration unit. The size fraction > 300 μm was visually examined and potential microplastic particles were analyzed by ATR-FTIR spectroscopy. The treatment of size class 20 μm < d < 300 μm was based on enzymatic-oxidative microwave-assisted "one-pot" matrix digestion in conjunction with analysis of the microplastics by time-efficient LDIR imaging. Total number concentrations ranged from 47 to 2154 microplastic particles per m³ (average for all stations: 500 ± 700 microplastic particles m^-3 (1 SD; n = 8)). In total, 20 polymer types were identified. The most common polymer types were polyethylene terephthalate (20 %) and acrylates/polyurethane/varnish (15 %). 93 % of the detected microplastics were smaller than 100 μm in length. Analysis of sample replicates indicates high spatio-temporal variations in microplastic pollution within the investigated region.

Microplastics in carnivorous fish species, water and sediments of a coastal urban lagoon in Nigeria

Plastic marine debris is a common source of pollution. Recent research has shown that plastic debris has a negative impact on marine organisms and the environment. For the first time, we investigated the presence of microplastics (MPs) in the Nigerian Lagos Lagoon ecosystem water, sediment, and the most important fish species (Hepsetus odoe, Chrysichthys nigrodigitatus, Oreochromis niloticus, and Lachnolaimus maximus). MPs were found in water, sediment, and three carnivorous fish species (H. odoe, C. nigrodigitatus, and L. maximus), except for herbivorous O. niloticus, raising concerns about the health of the Nigerian Lagos Lagoon ecosystem and the human food chain. Across the lagoon, fibres were more concentrated in the water, while fragments predominated in the sediment. Plastic debris from recreational, industrial, and domestic wastes contributed significantly to this contamination. Given the potential dangers of MPs to human health, it is critical to protect the ecosystem and its inhabitants in the Lagoon from plastic pollution. Our findings highlight the need for urgent measures to protect Nigeria's fragile coastal and marine ecosystems.

An optimized acidic digestion for the isolation of microplastics from biota-rich samples and cellulose acetate matrices

Plastic pollution is a growing concern. To analyze plastics in environmental samples, plastics need to be isolated. We present an acidic/oxidative method optimized to preserve plastics while digesting synthetic cellulose acetate and a range of organics encountered in environmental samples. Cellulose acetate was chosen for optimization as it can be purchased as a reference material, can co-occur with plastics in environmental samples and, if it can be completely digested, is a potential filter material for the collection of nano- and micro-plastics from natural waters. Other forms of particulate organic matter (POM) were chosen to provide a range of chemistries that might alter digestion efficiency and due to the interest in the community of isolating plastics from samples where these organics occur. For instance, microalgal POM occurs in lake and ocean waters, riverine POM in rivers, and inclusion of tuna provides a test for the suitability of the method for isolating plastics from animal tissues. The method is a one-pot overnight (16-18 h) digestion in 5 M nitric acid with 0.3 M sodium persulfate heated to 80 °C. The method provides quantitative removal of cellulose acetate (exceeding detection limits), near quantitative removal of microalgal POM and Albacore tuna tissue (>99%), but only 86% of urban river POM, all while retaining >99% by mass of C-C bonded polymers polyethylene, polypropylene, and polystyrene and >96% by mass of polyethylene terephthalate. Fourier transform infrared spectroscopy (FT-IR) and %-C content analysis confirmed plastic polymer stability during digestion. However, some additives in appear susceptible to digestion with FT-IR results indicating the loss of N,N'-ethylenebis(stearamide) from polyethylene. This method provides a simpler and more effective method than many in the literature. We present recommendations for the application of this method, as well as limitations and areas for future improvement.

Macro- and microplastics as complex threats to coral reef ecosystems

The impacts of macroplastics (macro-), microplastics (MPs, <5mm), and nanoplastics (NPs, <100 nm) on corals and their complex reef ecosystems are receiving increased attention and visibility. MPs represent a major, contemporary, sustainability challenge with known and unknown effects on the ocean, and coral reef ecosystems worldwide. However, the fate and transport processes of macro-, MPs, and NPs and their direct and indirect impacts on coral reef ecosystems remains poorly understood. In this study, we verify and briefly summarize MPs distribution and pollution patterns in coral reefs from various geographical regions and discuss potential risks. The main interaction mechanisms show that MPs may substantially affect coral feeding performance, proper skeletal formation, and overall nutrition and, thus, there is an urgent need to address this rapidly growing environmental problem. From a management perspective, macro-, MPs, and NPs should, ideally, all be included in environmental monitoring frameworks, as possible, to aid in identifying those geographical areas that are most heavily impacted and to support future prioritization of conservation efforts. The potential solutions to the macro-, MP, and NP pollution problem include raising public awareness of plastic pollution, developing robust, environmental, conservation efforts, promoting a circular economy, and propelling industry-supported technological innovations to reduce plastic use and consumption. Global actions to curb plastic inputs, and releases of macro-, MP, and NP particles, and their associated chemicals, to the environment are desperately needed to secure the overall health of coral reef ecosystems and their inhabitants. Global scale horizon scans, gap analyses, and other future actions are necessary to gain and increase momentum to properly address this massive environmental problem and are in good accordance with several relevant UN sustainable development goals to sustain planetary health.

High Heterotrophic Plasticity of Massive Coral Porites pukoensis Contributes to Its Tolerance to Bioaccumulated Microplastics

Scleractinian corals have been observed to be capable of accumulating microplastics from reef environments; however, the tolerant mechanism is poorly known. Here, we examined the response of Porites pukoensis to microplastic pollution by analyzing algal symbiont density, energetic metabolism, and caspase3 activities (representing the apoptosis level) in the coral-Symbiodiniaceae association. The environments of three fringing reef regions along the south coast of Sanya City, Hainan Province of China, were polluted by microplastics (for example, microplastic concentrations in the seawater ranged from 3.3 to 46.6 particles L^-1), resulting in microplastic accumulation in P. pukoensis (0.4-2.4 particles cm^-2). The accumulation of microplastics was negatively correlated to algal symbiont density in the corals but not to caspase3 activities in the two symbiotic partners, demonstrating that P. pukoensis could tolerate accumulated microplastics despite the decrease of algal symbiont density. Furthermore, results from the carbon stable isotope and cellular energy allocation assay indicated that P. pukoensis obtained energy availability (mainly as lipid reserves) using the switch between heterotrophy and autotrophy to maintain energy balance and cope with accumulated microplastics. Collectively, P. pukoensis achieved tolerance to microplastic pollution by maintaining energy availability, which was largely attributed to its high heterotrophic plasticity.

Microplastics in the Atmosphere and Water Bodies of Coastal Agglomerations: A Mini-Review

Microplastics are ubiquitously in various environments from the equator to the poles. Coastal agglomerations act as both a source and sink connecting the global microplastic cycles of oceans and continents. While the problem of microplastics is particularly severe and complex in the coastal zones, where both inland and marine pollution are concentrated, the present study aimed to provide hot topics and trends of coastal urban microplastic studies and to review the researches on microplastic pollution in the atmosphere and water bodies in coastal agglomerations in terms of characteristics, behavior, and health threat of microplastics. The results of the bibliometric analysis showed an increase in the annual output of microplastic research. Research hot topics and clusters were analyzed using the VOSviewer. Characteristics of microplastics varied in abundance, size, and polymer type in different environments and countries. Furthermore, coastal cities are taken as a system to sort out the input, output, and internal transmission pathways of microplastics. The health threat of microplastics to urban residents was briefly reviewed and the exposure and health risks of microplastics to infants and young children were of particular concern. Detailed and comprehensive studies on intervention and reduction in the transmission of microplastics between the atmosphere and water bodies, whether microplastics are harmful to infants and young children, and measures to reduce the risk of microplastic exposure are needed.

Uptake of microplastics by marine worms depends on feeding mode and particle shape but not exposure time

The uptake of microplastics into marine species has been widely documented across trophic levels. Feeding mode is suggested as playing an important role in determining different contamination loads across species, but this theory is poorly supported with empirical evidence. Here we use the two distinct feeding modes of the benthic polychaete, Hediste diversicolor (The Harbour Ragworm) (O.F. Müller, 1776), to test the hypothesis that filter feeding will lead to a greater uptake of microplastic particles than deposit feeding. Worms were exposed to both polyamide microfragments and microfibres in either water (as filter feeders) or sediment (as deposit feeders) for 1 week. No effect of exposure time was found between 1 day and 1 week (p > 0.19) but feeding mode was found to significantly affect the number of microfibres recovered from each worm (p < 0.001). When exposed to microfibers, filter feeding worms took up ≈15,000 % more fibres than deposit feeding worms (p < 0.001), whereas when feeding on microfragments there was no difference between feeding modes. Our data demonstrate that both feeding mode and particle characteristics significantly influence the uptake of microplastics by H. diversicolor. Using imaging flow cytometry, filter feeders were found to take up a broader size range of particles, with significantly more smaller and larger particles than deposit feeders (p < 0.05), commensurate with the range of plastics isolated from the guts of ragworms recovered from the environment. These results demonstrate that biological traits are useful in understanding the uptake of plastics into marine worms and warrant further exploration as a tool for understanding the bioaccessibility of plastics to marine organisms.

The use of microplastics as a reliable chronological marker of the Anthropocene onset in Southeastern South America

Microplastics (MPs) represent an emergent contamination marker. For this reason, we analyzed the vertical distribution of MPs in six sediment cores retrieved from the Patos-Mirim System, the world's largest coastal lagoonal system. The sediment cores span from mid Holocene to present times according to both radiocarbon and lead dating and are located close to both urban/industrial and agricultural regions. We identified a basal pre-disturbance MP-free zone in all cores and an uppermost contaminated 70-cm-zone, where a general increasing trend in MPs content resembling the human anthropization process was recorded. The predominant format of MPs was fiber, followed by fragments. The most commonly identified polymers were rayon, PVC, acrylate, polycarbonate and cellophane. Urban/industrial and agricultural activities were shown as clear sources of MPs, leading to comparable MPs concentration values in the sediment cores. Thus, MPs are collectively a reliable indicator of the Anthropocene onset, and in the Patos-Mirim System the most appropriate chronology can be assigned to the beginning of 1970s, matching the intensification of anthropogenic activities in the area.

Ingestion of microplastics and textile cellulose particles by some meiofaunal taxa of an urban stream

Microplastics (MPs) and textile cellulose are globally pervasive pollutants in freshwater. In-situ studies assessing the ingestion of MPs by freshwater meiofauna are few. Here, we evaluated MP and textile cellulose ingestion by some meiofaunal taxa and functional guilds of a first-order stream in the city of Florence (Italy) by using a tandem microscopy approach (fluorescence microscopy and μFTIR). The study targeted five taxa (nematodes, oligochaetes, copepods, ephemeropterans and chironomids), three feeding (scrapers, deposit-feeders, and predators), and three locomotion (crawlers, burrowers, and swimmers) guilds. Fluorescent particles related to both MPs and textile cellulose resulted in high numbers in all taxa and functional guilds. We found the highest number of particles in nematodes (5200 particles/ind.) and deposit-feeders (1693 particles/ind.). Oligochaetes and chironomids (burrowers) ingested the largest particles (medium length: 28 and 48 μm, respectively), whereas deposit-feeders ingested larger particles (medium length: 26 μm) than scrapers and predators. Pellets were abundant in all taxa, except for Chironomidae. Textile cellulose fibers were present in all taxa and functional guilds, while MP polymers (EVA, PET, PA, PE, PE-PP) differed among taxa and functional guilds. In detail: EVA and PET particles were found only in chironomids, PE particles occurred in chironomids, copepods and ephemeropterans, PA particles were found in all taxa except in nematodes, whereas particles made of PE-PP blend occurred in oligochaetes and copepods. Burrowers and deposit-feeders ingested EVA, PET, PA, PE and PE-PP, while crawlers and scrapers ingested PE and PA. Swimmers and predators ingested PE, PA and PE-PP. Our findings suggest a pervasive level of plastic and textile cellulose pollution consistent with an urban stream which propagates in the meiofaunal assemblage of the stream ecosystem.

Overviewing the Ground Reality of Microplastic Effects on Seafoods, Including Fish, Shrimps and Crabs: Future Research Directions

While plastics are already notorious for their accumulation in the environment, which poses environmental challenges, invisible microplastics (MPS) are an even greater challenge. This review focuses on consolidating the reports available on MP accumulation in edible marine and freshwater fishes, shrimps, and crabs. The reality as to whether MPs in these edible aquatic organisms are really a cause of high concern is questioned and discussed. While the entrails of aquatic organisms are reported to contain high levels of MPs, because these products are consumed after the removal of the entrails and gut area in the majority of cases, the MP threat is questionable. The existence of MPs in these aquatic sources is validated but their potency in harming humans, aquatic organisms, and other interlinked species is unassessed. To overcome the difficulty in tracing the movement of MPs in a bigger ecosystem, this review proposes laboratory-based pilot studies mimicking real-world conditions, which will help us to understand the kinetics of MPs in the food chain. The effects of MPs on human welfare and health are yet to be assessed, and this is another gap that needs attention.

Multispecies Assessment of Anthropogenic Particle Ingestion in a Marine Protected Area

We have applied a multispecies ecosystem approach to analyse the ingestion of anthropogenic particles (AP) in the gastrointestinal tract of 313 individuals (17 fish species and 8 invertebrate species) from pelagic, demersal and benthic habitats in a marine protected area off the Western Mediterranean (Cabrera National Park). We have quantified and characterized the ingestion at several taxonomic levels of fish, sea urchins, sea cucumbers, bivalves, and jellyfish in relation to biotic/abiotic factors based on taxonomic groups, trophic guilds (functional groups) and habitats. AP ingestion occurrence ranged from 26 to 100% with no significant differences among taxonomic groups. The fish within the MPA showed an overall ingestion occurrence ranging from 0 to 100%, the echinoderms from 29 to 100%, the bivalves from 72 to 96% and the jellyfish 36% ingestion. The ecosystem approach applied to evaluate overall AP ingestion within the species reported that for trophic guilds, the omnivorous species ingested the highest amounts of anthropogenic items, while herbivores ingested significantly fewer items than all other trophic guilds. Moreover, no significant differences were found amongst habitats, indicating a homogeneous spatial distribution of APs at all studied habitats. The multispecies approach provided insight into the high APs exposure to species within Cabrera MPA, highlighting the potential harm linked with marine litter that threatens marine biodiversity.

First assessment of microplastic and artificial microfiber contamination in surface waters of the Amazon Continental Shelf

The composition and distribution of microplastics (MPs) in the Brazilian Amazon Continental Shelf surface waters are described for the first time. The study was conducted during the 2018 rainy and dry seasons, using 57 water samples collected with aluminum buckets and filtered through a 64-μm mesh. The samples were vacuum-filtered in a still-air box, and the content of each filter was measured, counted, and classified. A total of 12,288 floating MPs were retrieved; particles were present at all 57 sampling points. The mean MP abundance was 3593 ± 2264 items·m^-3, with significantly higher values during the rainy season (1500 to 12,967; 4772 ± 2761 items·m^-3) than in the dry season (323 to 5733; 2672 ± 1167 items·m^-3). Polyamides (PA), polyurethane (PU), and acrylonitrile butadiene styrene (ABS) were the most common polymers identified through Fourier Transform Infrared Spectroscopy (FTIR) analysis. Cellulose-based textile fibers were also abundant (~40%). Our results indicate that the Amazon Continental Shelf is contaminated with moderate to high levels of MPs; the highest abundances were recorded at stations near land-based sources such as river mouths and large coastal cities.

Occurrence of microplastics in gastrointestinal tract of fish from the Gulf of Guinea, Ghana

Over the past decades, there has been a growing concern about microplastics pollution in global aquatic habitats and its potential impact on human health. This study was carried out to determine the presence of microplastics in fish of economic importance in Ghana. Microplastics were found to be abundant in all investigated samples, with 68 % of the fishes contaminated with microplastics and a total of 133 plastic items identified in the fish. The presence of fibers, black coloured particles, and microplastics in the size range of 0.5-1.0 mm was the most abundant in the samples examined. Three polymers specifically, polyethylene, polyvinyl acetate, and polyamide were identified in the study. The presence of microplastics in the fishes investigated may pose severe ecological and health concerns, and hence comprehensive policies targeted at preventing plastic pollution of Ghana's maritime environment is warranted.

Hidden problems in geological heritage sites: The microplastic issue on Saint Mary's Island, India, Southeast Arabian Sea

Microplastics (MPs) have become a dominant constituent of several oceanic islands. This study focuses on the occurrence and distribution of MPs present in the beach sediments of Saint Mary's Island (SMI), a geological heritage site located in the south-eastern part of the Arabian Sea. The average (standard deviation) abundance of MPs on this island was 97.18 (80.49) particles/kg. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy revealed that MPs are composed of high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyamide (PA). Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) highlighted the presence of Cr, As, Pb, and Cd (harmful pollutants) on MP surfaces. The MPs in the SMI are largely contributed by the nearby fishing harbour, touristic beaches and estuaries. The results of this study, act as a starting point for continuous environmental monitoring in this unique region of the world.

Microplastic occurrence in deep-sea fish species Alepocephalus bairdii and Coryphaenoides rupestris from the Porcupine Bank (North Atlantic)

Microplastic occurrence in marine biota has been reported in a wide range of animals, from marine mammals and seabirds to invertebrates. Commercial and shallow-water fish have been the subject of numerous works on microplastic ingestion, given their importance in human diet and accessibility. However, little is known about microlitter occurrence in fish species inhabiting the dark ocean, in the bathyal zone and there is a high degree of uncertainty about microplastic distribution in offshore areas and the deep sea. In this study, bathydemersal species Alepocephalus bairdii and Coryphaenoides rupestris from the Porcupine Bank caught between 985 and 1037 m depth were inspected for microdebris. The stomach contents were digested by the alkaline method plus ethanol addition to avoid clogging. A filament of Polyethylene Terephthalate (PET) was found in the stomach of a specimen of A. bairdii, representing 4% of the total sampled specimens of this species (i.e. prevalence in n = 25). However, when considering potential microplastics, the prevalence increased to 28% in both, A. bairdii and C. rupestris. This work provides the first baseline study of microplastic items in fish from such depths in the Atlantic and suggests these species might be used as biomonitors in future research.

Impacts of microplastics on scleractinian corals nearshore Liuqiu Island southwestern Taiwan

Seawater, sediments, and three genera of wild scleractinian corals were collected from four coral reef areas nearshore Liuqiu Island, southwestern Taiwan. Abundance, characteristics (sizes, colors, shapes, and polymer types), and enrichment of microplastics (MPs) in the corals, and their impacts on coral cover were determined. The average MPs abundances were 0.95, 0.77, and 0.36 item/g for Galaxea sp, Acropora spp, and Pocillopora sp, respectively. The MPs abundance was relatively higher on the coral surfaces than inside the skeletons, dominated by blue rayon-fibers, correspondingly observed in seawater and sediments. Large-size colorless MPs tended to be mis-ingested by Galaxea sp. (71%) compared with Pocillopora sp. (43%) and Acropora spp. (31%). The low hard coral cover (12.5%) observed at Yufu (L1) on the northeastern coastal zone nearby tourism center of Liuqiu Island where correspondingly associated with high MPs abundance in seawater (10 item/L), sediments (260 item/kg), and corals (0.60 item/g). Tourism induced sewage discharges and sailing activities significantly contributed to the MPs pollution, probably contributing to the loss of coral cover. High MPs enrichment in corals (EF_MP = 25-283) shows that the marine MPs pollution can critically threaten coral reef ecosystems. Fibrous MPs present inside the coral skeleton serve as potential indicator of MPs' impact on corals-with the dominance of textile-related rayon and polyester/PET microfibers in the coral reef zones. This study provided valuable information for coral conservation and coastal management.

Assessment of microplastic contamination in the urban lower Chao Phraya River of Bangkok city, Thailand

Rivers are one of the major pathways for the transportation of microplastics (MPs) from land-based sources to the ocean. However, there are only a few studies on MPs in freshwater environments, particularly in Asian countries. In this study, MP contamination in the Chao Phraya River in selected locations distributed throughout Bangkok, Thailand was investigated. MPs were collected using a Manta net with a mesh size of 335 μm. After digestion and distinction based on density, MPs were observed using a stereomicroscope, and polymer types were identified using Fourier Transform Infrared Spectroscopy. MP concentrations detected in the five sampling locations of the river water from upstream to downstream were 11, 35, 40, 15, and 4 particles/m³, with an average concentration of 21±16 particles/m³. Most MPs were identified as either fragments or sheets/films. Polypropylene was the dominant polymer type. The number of MPs increases as their size decreases. Potential sources of MPs may include the degradation of single-use plastic products, especially containers and plastic packaging. MP concentrations and characteristics varied for different locations, indicating different sources and pathways of MPs in urban contexts. Further investigation on the different pathways of the transportation of MPs to river water from land-based sources is required.

Tracing microplastics from raw water to drinking water treatment plants in Busan, South Korea

The increasing amount of plastic waste has raised concerns about microplastics (MPs) in aquatic environments. MPs can be fragmented into nanoplastics that can pass through water treatment processes and into tap water; potentially threatening human health because of their high adsorption capacity for hazardous organic materials and their intrinsic toxicity. This case study investigates the identification, fate, and removal efficiency of MPs in Korean drinking water treatment plants. Two sites on the Nakdong River, two lake reservoirs (raw water sources), and four corresponding drinking water treatment plants were targeted to trace the amounts, types, and sizes of MPs throughout the treatment process. Monthly quantitative and qualitative analyses were conducted by chemical image mapping using micro-Fourier-transform infrared spectroscopy. MPs larger than 20 μm were detected, and their sizes and types were quantified using siMPle software. Overall, the number of MPs in the river sites (January to April and October to November) exceeded those in the reservoirs, but only slight differences in the number of MPs between rivers and lake reservoirs were detected from June to October. The annual average number of MPs in River A, B and Lack C and D was not distinctively different (2.65, 2.48, 2.46 and 1.87 particles/L, respectively). The majority of MPs found in raw waters were polyethylene (PE)/polypropylene (PP) (> 60%) and polyethylene terephthalate (PET)/poly(methyl methacrylate) (PMMA) (20%), in addition to polyamide (<10%) in the river and polystyrene (<10%) in the lake reservoirs. Approximately 70-80% of the MPs were removed by pre-ozonation/sedimentation; 81-88% of PE/PP was removed by this process. PET/PMMA was removed by filtration. Correlation of MPs with water quality parameters showed that the Mn concentration was moderately correlated with the MP abundance in rivers and lake reservoirs, excluding the lake with the lowest Mn concentration, while the total organic carbon was negatively correlated with the MP abundance in both rivers (A and B) and lake reservoir C.

Occurrence of microplastics in bivalve molluscs Anomalocardia flexuosa captured in Pernambuco, Northeast Brazil

Microplastics (MPs) are widely distributed in marine ecosystems, and their ubiquitous presence is raising concern, particularly about possible impacts on fisheries resources. In tropical regions, shellfish fisheries represent an essential source of income and subsistence for traditional communities, and adverse effects on these resources may have severe consequences on human health. In the present study, bivalve molluscs of the species Anomalocardia flexuosa, captured in the region of the Itapessoca estuary in Pernambuco, Brazil, were analysed. A total of 90% of the individuals presented MP particles in their tissue. We observed an average of 5.15 ± 3.80 MP particles per individual, and for each gram of soft tissue, 3.66 ± 2.59 MP particles were found. Our results showed that MPs are present in clams captured on the Pernambuco coast and that the species studied proved to be suitable for monitoring the levels of microplastic pollution.

Microplastic pollution in the surface seawater in Zhongsha Atoll, South China Sea

The prevalence of microplastics in the marine environment has attracted extensive attention. So far, no information is known regarding the temporal and spatial variations of microplastics in Zhongsha Atoll. This study, for the first time, comprehensively investigated the occurrence and distribution of microplastics in the surface seawater in Zhongsha Atoll based on two ocean cruises. The abundances of microplastics measured in the surface seawater of Zhongsha Atoll were in the ranges of not detected (ND) to 67 items/m³, and ND to 160 items/m³ in 2019 and 2020, respectively. All microplastics detected in Zhongsha Atoll were fibers, most of which were transparent and less than 2 mm. Polyethylene terephthalate was the dominating composition of microplastics. These results suggested that sewage, surface runoff, atmospheric deposition by neighboring land, and fishing activities may be the primary pollution sources. This study provides critical information on microplastic pollution in Zhongsha Atoll for the first time, calling for more research in the management of marine plastic debris in the future.

Microplastic occurrence in the gastrointestinal tract and gill of bioindicator fish species in the northeastern Mediterranean

Microplastic pollution is an extremely emerging problem and its potential threats to the aquatic organisms were investigated worldwide. In this study, four different commercial fish species (Mullus barbatus (Linnaeus, 1758), Mullus surmuletus (Linnaeus, 1758), Mugil cephalus (Linnaeus, 1758), Saurida undosquamis (Richardson, 1848)) were used as a bioindicator to assess the microplastic pollution in the northeastern Mediterranean. The frequency of occurrence in the gastrointestinal tract (GIT) and gill was varied between 66-100% and 68-90%, respectively. The highest microplastic abundance was detected at the GIT of M. cephalus sampled from Asi River estuary. The majority of extracted microplastics were fiber, black in color and less than 1 mm in size. Fourier Transform Infrared Spectroscopy (FTIR) indicated the most common polymer type as polyethylene. This study is the first study examining the microplastic existence in gill and results obtained in this study improve the knowledge about the relationship of microplastic ingestion in fish and environmental conditions in the Northeastern Mediterranean Sea.

The patterns of trophic transfer of microplastic ingestion by fish in the artificial reef area and adjacent waters of Haizhou Bay

Plastic pollution has become a threat to the global marine environment. Many studies have shown that marine organisms are at risk of plastic ingestion, but there is still a lack of relevant research in the artificial reef area and adjacent waters of Haizhou Bay, located in the western Yellow Sea. The study of MPs will provide useful information for MPs pollution in the artificial reef food webs, as well as the understanding of MPs trophic transfer by reef fish. In this study, we quantified plastic ingestion by marine fish in artificial reef areas and adjacent waters (Natural area, NA; Aquaculture area, AA; Estuary area, EA; Artificial reefs area, AR and Comprehensive effective area, CEA) and analysed the related possible influencing factors. Of the 146 fish samples examined, 100% of fish ingested plastics, and 98.9% of these particles were microplastics (MPs) (<5 mm), with 3.00 ± 2.63 pieces/fish. The main types and colours of MPs were fibre (95.9%) and blue (84%). The MP quantity of AR and AA were significantly higher than that of CEA (P < 0.05) and there is no significant difference among other habitats. The MP ingestion by pelagic fishes was significantly lower than that of demersal fishes (P < 0.05). MP ingestion by omnivores was significantly higher than that by carnivores and planktivores (P < 0.05). The body length (body weight) of four species (Larimichthys polyactis: 17.7-16.7 cm (16.01-59.41 g); Collichthys lucidus: 8.1-14.3 cm (19.65-56.92 g); Tridentiger barbatus: 5.9-9.2 cm (3.37-19.1 g); Cynoglossus joyneri: 10.1-18.7 cm (5-45 g)) had no significant correlation with MP ingestion (P > 0.05). Our results showed that MPs in this region are ubiquitous (i.e., the MP ingestion rate was as high as 100%). We infer that there is a transfer mechanism in MPs from pelagic to benthic fish in this area, and there is weak biomagnification with the trophic transfer of the food chain (TMF = 1.62). However, more practical studies still need to verify whether MPs are actually transferred to humans through trophic transfer from the marine food web.

Occurrence and Quantification of Natural and Microplastic Items in Urban Streams: The Case of Mugnone Creek (Florence, Italy)

The terrestrial environment is an important contributor of microplastics (MPs) to the oceans. Urban streams, strictly interwoven in the city network and to the MPs' terrestrial source, have a relevant impact on the MP budget of large rivers and, in turn, marine areas. We investigated the fluxes (items/day) of MPs and natural fibers of Mugnone Creek, a small stream crossing the highly urbanized landscape of Florence (Italy) and ending in the Arno River (and eventually to the Tyrrhenian Sea). Measurements were done in dry and wet seasons for two years (2019-2020); stream sediments were also collected in 2019. The highest loads of anthropogenic particles were observed in the 2019 wet season (109 items/day) at the creek outlet. The number of items in sediments increased from upstream (500 items/kg) to urban sites (1540 items/kg). Fibers were the dominant shape class; they were mostly cellulosic in composition. Among synthetic items, fragments of butadiene-styrene (SBR), indicative of tire wear, were observed. Domestic wastewater discharge and vehicular traffic are important sources of pollution for Mugnone Creek, especially during rain events. The study of small creeks is of pivotal importance to limit the availability of MPs in the environment.

Microplastic pollution in surface seawater and beach sand from the shore of Rayong province, Thailand: Distribution, characterization, and ecological risk assessment

The distribution, characteristics, and ecological risk of microplastics in beach sand and seawater samples collected along the shore of Rayong province, Thailand, were investigated in this study. The average microplastics abundance in beach sand and seawater was 338.89 ± 264.94 particles/kg d.w. and 1781.48 ± 1598.36 particles/m³, respectively. Beach sand and seawater had the most yellow-brown particles and transparent microfibers, respectively. The most common microplastics (100-500 μm) and polyethylene were found. In beach sand, the potential ecological risk (RI) is classified as minor, while in seawater, it is classified as medium. The PLI_zone in beach sand and seawater was Hazard Level II and Hazard Level IV, respectively. Despite their apparent proximity, the non-correlation between risk levels in beach sand and seawater may be due to polymer type variations influenced by the different land-based and sea-based sources.