Influence of biological, ecological, and anthropogenic factors on microplastic contamination in coastal fishes from Southeastern Brazil

Microplastic contamination in pelagic and coastal fish from Malaysian waters: Tissue-specific distribution, polymer characteristics, and environmental risk indicators.

Comparison of microplastic intake in two fish species from different functional feeding groups in Europe's second-largest river.

Microplastic distribution in different tissues of small pelagic fish of the Northeast Atlantic Ocean

Contamination of seafood with microplastics (MPs) poses a threat to food safety and public health, particularly in coastal regions where dried fish is a dietary staple. This study assessed MP contamination in fresh and sun-dried fish collected from processing centers along the Gulf of Mannar, southeast India, and evaluated potential post-harvest contamination sources, including curing salt, rinse water, processing-area soil, and airborne fallout. MPs were detected in all samples. Dried fish muscle contained significantly higher MP loads (7.25 ± 1.36 items g⁻1) than fresh fish (3.67 ± 1.04 items g⁻1), indicating substantial contamination during processing. Spearman correlation and principal component analysis revealed strong associations between MP levels in dried fish and curing salt (ρ = 0.99), airborne fallout (ρ = 0.97), and processing-area soil (ρ = 1.00), with these factors jointly explaining over 85% of the total variance. PERMANOVA further confirmed that processing centers accounted for 48% of the variance in MP loads in dried fish, compared with only 12% attributable to species identity. Source apportionment analysis indicated proportional contributions from curing salt (38%), airborne fallout (27%), and processing-area soil (20%). Fibers dominated MP morphology (62% in dried fish), while polymer and color profiles suggested inputs from ambient air, packaging materials, plastic trays, and salt. Based on FAO/WHO seafood consumption models, estimated adult exposure was 170,820 MPs year⁻1, with dried fish contributing 44% (75,400 MPs year⁻1) despite lower consumption frequency. These findings highlight the need for improved hygiene in traditional fish processing to reduce dietary MP exposure.

Microplastic pollution in the environment and organisms of Xiangshan Bay, East China Sea: An area of intensive mariculture

Microplastics (MPs) have attracted global concern because of their harmful effects on marine biota; their toxic properties can negatively impact aquatic ecosystems. Fish is an essential source of protein for humans, playing a crucial role in daily food intake. Until recently, MPs were addressed primarily as environmental pollutants, but they are now increasingly recognized as contaminants in the food supply. The present review has comprehended the current knowledge of MP contamination in freshwater and marine fishes of Asia, including 112 peer-reviewed sources from 2016 to 2023. The review recorded 422 Asian fishes (345 marine and 77 freshwater) to be contaminated with MPs. Clarias gariepinus and Selaroides leptolepi have shown maximum MP contamination in the freshwater and marine environments of Asia, respectively. Omnivorous and carnivorous fishes exhibited higher susceptibility to ingesting MPs. Benthopelagic, demersal, and reef-associated habitats were identified as more prone to MP accumulation. In both freshwater and marine environments, China has the highest number of contaminated species among all the countries. Pollution indices indicated high MP contamination in both freshwater and marine environments. A prevalence of fibers was recorded in all fishes. Black- and blue-colored MPs of <500 µm-1 mm size were found dominantly. Polyethylene terephthalate and polyethylene were recorded as the prevalent plastic polymers in freshwater and marine fish, respectively. Overall, the review served as a comprehensive understanding of MP concentrations and variations between species, between feeding habits, and between geographic locations, which can be pivotal for addressing pressing environmental challenges, protecting human health, and fostering global sustainability efforts in the face of escalating plastic pollution. Environ Toxicol Chem 2024;43:671-685. © 2024 SETAC.

Microplastics (MPs) are ubiquitous in river and freshwater ecosystems. However, the hydraulic and hydrological mechanisms that regulate the activation and emissions of MPs from both the land surface and subsurface into rivers are not well understood. This study aims to quantify the instream MP concentration and MP load in a remote headwater catchment river (Taff Bargoed, Wales, UK), which drains the UK's largest opencast coal mine (Ffos-y-fran), over a two-year period. Small fibers (< 1mm) composed of acrylic and polyester dominated the MPs found in the Taff Bargoed, while less commonly observed MP fragments were mostly composed of polysulfone. River MP concentrations ranged from 0.27 to 28.87MP/m³ (average: 14.60±10.31MP/m³), and MP load ranged one order of magnitude from 0.08 to 3.04MP/s (average: 1.42±0.81MP/s). Statistically significant relationships were found between MP concentration, the number of dry weather hours and river discharge, which indicated rainfall-runoff induced, source limited, dilution effects on instream MP concentration. A negligible relationship between MP load and river discharge was observed, which suggests that MP load variability was independent of flow conditions, dry weather hours, and the MP concentration in the Taff Bargoed. Significant positive relationships between MP concentration and instream total suspended solids were also observed, indicating that this may provide a useful proxy for estimating MP variation in the Taff Bargoed. No longitudinal variation in MP concentration over a 2km reach was observed, where differences in flow and drainage area were negligible, however, MP concentration increased by a factor of 2-4 downstream of an inflowing tributary, also sourced from the Ffos-y-fran coal mine. Overall, the results of this study provide evidence that mining activities can contribute MPs in rural and remote rivers, with their contribution being regulated by the hydraulic and hydrological processes in the catchment.

Lake Gölcük represents a significant natural freshwater resource within the Gediz River basin, located in the Ödemiş district of İzmir, Türkiye. The ecosystem has experienced considerable anthropogenic pressure from expanding settlements and tourism activities. This study aimed to assess the spatial distribution and severity of microplastic (MP) contamination in the lake. Microplastics (MPs) were quantified and characterized in water, sediment, fish muscle, gastrointestinal tract, and macroinvertebrate tissues collected from three spatially distinct stations using integrated morphological and spectroscopic methods. Macroinvertebrate samples were processed for MP contamination following standardized field sampling and laboratory protocols. The results show that Station 2, corresponding to the primary recreational zone, exhibited the highest MPs concentrations in water (81.33 ± 4.16 particles L⁻ 1 ) and sediment (30.00 ± 4.16 particles kg⁻ 1 ). In macroinvertebrates, MP loads ranged from 0.01 to 0.09 particles mg⁻ 1 , with peak values observed in Haliplidae and Veliidae taxa. European perch (Perca fluviatilis) contained 7.00 ± 2.00 particles g⁻ 1 in muscle tissue and 1.67 ± 0.58 particles g⁻ 1 in the gastrointestinal tract, whereas gibel carp ( Carassius gibelio ) from Station 1 showed no detectable MPs. Fibers dominated the morphotype distribution, with blue, black, and transparent particles most prevalent. Polyethylene, polypropylene, polyethylene terephthalate, and nylon constituted the predominant polymer compositions. Collectively, these findings confirm substantial MP contamination across both abiotic (water, sediment) and biotic (fish, macroinvertebrates) compartments of Lake Gölcük, posing potential ecological risks to resident biota and overall ecosystem integrity. The results contribute critical baseline data on MP distribution in Turkish inland waters and underscore the urgent need for protective measures amid escalating tourism pressure.

Wastewater treatment plants (WWTPs) have been described as key contributors of microplastics (MPs) to aquatic systems, yet temporal fluctuations in MP concentrations and loads downstream are underexplored. This study investigated how different sampling frequencies (hourly, weekly, and monthly) affect MP estimates in a stream linked to a single WWTP. Utilizing fluorescence microscopy and Raman spectroscopy, considerable hourly variations in MP concentrations were discovered, while the polymer composition remained consistent. This temporal variability in MP loads was influenced by MP concentration, discharge rates, or a mix of both. These results show a high uncertainty, as relying on sparse snapshot samples combined with annual discharge data led to significant uncertainties in MP load estimates (over- and/or underestimation of emissions by 3.8 billion MPs annually at this site). Our findings stress the necessity of higher-frequency sampling for better comprehending the hydrodynamic factors influencing MP transport. This improved understanding enables a more accurate quantification of MP dynamics, crucial for downstream impact assessments. Therefore, preliminary reconnaissance campaigns are essential for designing extended, representative site-monitoring programs and ensuring more precise trend predictions on a larger scale.

Microplastics (MPs) contamination in fish species was one of the emerging environmental issues as a result of the widespread presence of plastic pollution in the environment. The presence of MPs in Thailand's freshwater was scant, and in contrast to other countries, little was known about the presence of this contaminant in freshwater fish. Hence, the purpose of this study was to examine the abundance, characteristics, and variation of MPs in various Thai commercial freshwater fish species. In order to compare the differences in MP ingestion rates across different feeding zones, 166 fish representing 24 species from various feeding zones were collected. MPs were found in the gastrointestinal tracts (GIT) of all fish samples tested, which was a substantially larger number than previously reported in other locations. Of all the fish species, Anabas testudineus, Labeo rohita, and Oreochromis mossambicus had the highest concentration of MPs (34.90 ± 21.43, 34.50 ± 7.78, 34.10 ± 11.15 items/individuals). Microscopical examinations showed that the majority of MPs were fiber-shaped and blue in color. Fourier transform infrared analysis (FTIR) showed that the polymers found in fish GIT were polyethylene, polypropylene, polyethylene terephthalate, polyvinyl acetate, poly (methyl vinyl ether), poly (methyl vinyl ether), polybutadiene, poly (ethylene-co-propylene), poly (ethylene glycol) tetrahydrofurfuryl ether, poly (methyl phenyl siloxane), poly (styrene-co-divinylbenzene), and polyvinylidene fluoride. The results of this study demonstrate that demersal fish had a higher concentration of MPs than benthopelagic and pelagic fish, indicating that plastic ingestion in fish may be related to the feeding habitat. However, it was not discovered that differences in the fish's body weight and length affected the MPs' ingestion. Our findings will help people in Thailand understand which freshwater fish and fish from which feeding zones are more contaminated with MPs for human consumption.

Microplastics (MPs) are an emerging class of pollutants with growing evidence of their accumulation in aquatic organisms. This study assessed the presence, characteristics, and ecological risks of MPs in the gills and gastrointestinal tracts (GITs) of five fish species from Anzali Wetland, Iran: Prussian carp (Carassius gibelio), perch (Perca fluviatilis), tench (Tinca tinca), common carp (Cyprinus carpio), and northern pike (Esox lucius). The average MPs abundance was 5.50 ± 3.36 particles per individual, with Tinca tinca showing the highest contamination (8.16 ± 4.45 MPs) and Perca fluviatilis the lowest (2.60 ± 1.26 MPs). Omnivorous and benthic species exhibited significantly higher MPs loads compared to carnivorous and pelagic species. Most MPs were blue (38%), fiber-shaped (78%), and sized between 250 and 500 µm (26%), with polyethylene, polypropylene, and polyamide identified as the dominant polymer types. Ecological risk assessment indicated a high potential threat to the wetland’s biodiversity. These findings demonstrate that MPs are bioaccumulating in key fish species of Anzali Wetland, with implications for food webs and human health. The study underscores the urgent need for stricter pollution control, enhanced public awareness, and improved methodologies for detecting smaller MPs and nanoplastics to effectively monitor and mitigate this growing environmental threat.

&amp;lt;p&amp;gt;Microplastics (MPs) are becoming an important component of suspended particulate matter (SPM), especially in estuaries which are hotspots of MPs pollution. Most SPM in estuarine water are removed via flocculation and further deposited. Therefore, we hypothesise that there is an efficient removal process for MPs by flocculation, which are expected to decrease the overall load of MPs in the marine environment. Here we systematically studied and quantified the influence of MPs properties (size, shape, density, polymer type and weathering condition) on flocculation behavior with suspended sediment in estuary conditions.&amp;amp;#160;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;We chose over 20 types of MPs with different properties for 8 size ranges from (10-300 &amp;amp;#181;m for fragments and microbeads, and 10-1000 &amp;amp;#181;m in length for microfibers, respectively). The MPs with different properties and suspended sediment were flocculated in artificial seawater, and the MPs in the system were observed using fluorescence microscopy to distinguish the incorporated MPs and suspended MPs. The incorporation rate (IR) is the ratio of incorporated MPs to total MPs, which is the parameter to evaluate the interaction between MPs and flocs.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The IR decreased with increasing size for fragments and microbeads, and also decreased as the diameter of microfibers rose. The IR for fragments smaller 20 &amp;amp;#181;m is extremely high, from 94.8% to 100%, but gradually decreased with increasing size. For fragments larger than 200 &amp;amp;#181;m, the IR of Polyethylene (PE), Polypropylene (PP) and Polystyrene (PS) are lower than 20%, while higher than 50% for Polyethylene terephthalate (PET) and Polyvinyl chloride (PVC). The IR of PE microbeads is significantly lower than those of fragments. When the diameter of microfibers are smaller than 20 &amp;amp;#181;m, the IRs are always higher than 90%, and the length has no effect on IR. While the IR of microfibers decreased with the length increasing when the diameter of microfibers is larger than 30 &amp;amp;#181;m. According to extensive comparisons between 20 types of MPs, we found that the IR is normally higher in the small size, elongated, angular, high density, weathered, chemically active MPs, while lower in the large size, spherical, low density, pristine and chemically inactive MPs. The size plays the most important role, followed by shape.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;There is an evidence that MPs are likely to be removed from the water column and hence estuary sediments are important sinks for MPs. This process reduces overall load to marine environments, but this is selective and depends on the characteristics of MPs. This study offers a reference to predict the preferential removal behavior of MPs in the estuary.&amp;lt;/p&amp;gt;

Pollution from synthetic microparticles such as microplastic (MPs) is of global concern. Semi-synthetic microparticles, also known as manufactured natural polymers (MNPs), have received much less scientific attention, despite their morphological similarity to MPs, comparable chemical additives, and the shared potential to act as vector for chemical substances and microorganisms. This study assessed MP and MNP levels in five popular seafood species: sand whiting (Sillago cillata), squids (Loligo spp.), eastern king prawns (Melicertus plebejus), blue swimmer crabs (Portunus armatus), and flatheads (family Platycephalidae) sold fresh in local fish markets from the Gold Coast, Australia. Samples from three tissue types (gill, gut, and muscle) were digested with 10% KOH and filtered through 5-micron stainless steel filter meshes. Visual microscopic screening was carried out for isolated microparticles, and size, shape, and colour were recorded; then, isolated suspected microparticles were analysed by μ-FTIR to identify the polymer type. Our results show that 88.6% of seafood available in local fish markets on the Gold Coast was contaminated with at least one particle of MP or MNP. Pelagic species contained a higher particle concentration (0.630±0.064 particles/g) compared to demersal species (0.130±0.019 particles/g. Non-edible tissues exposed to the external environment (gill and gut) contained significantly higher concentrations (0.545±0.046 particles/g) of microparticles compared to edible tissue (muscle) (0.203±0.025 particles/g). There was 1.1-3.2 time more MNPs than MPs in all tissue samples except in prawn muscle and flathead gill tissues, indicating that MNPs may pose a greater threat than previously recognised.

Circulation of fibrous microplastic (microfiber) in sewage and sewage sludge treatment processes

Coastal fisheries are essential to Pacific Island communities, providing vital nutrition, livelihoods, and cultural value, yet microplastic (MP) contamination poses a growing threat to both ecosystem and human health. This study presents a regional assessment of microplastic contamination in coastal fish across four Pacific Island Countries and Territories (Fiji, Tonga, Tuvalu, and Vanuatu), based on the compilation of four methodologically standardized datasets, enabling us to evaluate whether regional patterns of contamination are linked to the ecological traits of fish. A total of 878 fish from 138 species were analysed to reveal widespread ingestion (32.7% prevalence; 0.76 ± 0.05 MPs/individual), with Fiji exhibiting the highest contamination (74.5% frequency). Reef-associated invertivores such as Lethrinus harak showed elevated risks (80% contaminated in Fiji), driven by fiber-dominated particles (65–95%), while ecological traits (benthic feeding, reef habitats) increased exposure compared to nearshore pelagic species. Disparities emerged between nations, with Fiji’s sites exceeding global averages despite remoteness, whereas Vanuatu’s low fish contamination suggests restricted dispersal, successful waste management influences, or differential bioaccumulation pathways. Polypropylene, polyethylene, polyethylene terephthalate, and nylon were the dominant (~11–43%) polymer types across all countries. The findings highlight the essential need to incorporate the Pacific Island data into global pollution assessments to better represent tropical Pacific marine ecosystems. This work establishes a standardized baseline for microplastics in the Pacific coastal fish, providing a framework to guide future research on ecological impacts while highlighting the need to integrate these data into regional and global plastics negotiations. The study underscores the importance of expanding monitoring to underrepresented PICTs to better understand contamination drivers in island ecosystems.