Microplastics ingested by freshwater fish in rivers of the Syr Darya basin and associated ecological risks.

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.

Insights into microplastic exposure routes in the earthworm (Eisenia fetida): Gut and skin.

Accumulation, tissue distribution, and biochemical effects of polystyrene microplastics in the freshwater fish red tilapia (Oreochromis niloticus)

Uptake, accumulation and associated cellular alterations of environmental samples of microplastics in the seaworm Hediste diversicolor

Microplastics (MPs) and brominated flame retardants (BFRs) represent a synergic threat for aquatic environments and organisms' health status, with an additional concern over food quality and food security for species of commercial interest. In this study, the ingestion of MPs, levels of polybrominated diphenyl ethers (PBDEs), and hexabromocyclododecane (HBCDs) were assessed in organisms from two lakes of Central Italy, with the aims of exploring the bioavailability of these pollutants in freshwater environments, the possible translocation of MPs from digestive to edible tissues, and the relationship between MPs ingestion and bioaccumulation of BFRs. The fish Perca fluviatilis, Anguilla anguilla, Carassus auratus, and the crayfish Procambarus clarkii, all species commercialized for human consumption, were caught in Trasimeno Lake; moreover, P. fluviatilis and Rutilus rutilus were also sampled in Piediluco, a lake strongly influenced by industrial and anthropogenic activities, where fishing for commercial purpose is forbidden. With the exception of C. auratus which showed the highest frequency of MPs ingestion (75%), species from Piediluco Lake exhibited a more elevated percentage of organisms positive to MPs ingestion (45%) and higher levels of PBDEs and HBCDs (mean values of 343 and 792 pg/g, respectively, in P. fluviatilis; 445 and 677 pg/g, respectively, in R. rutilus) than Trasimeno species (25% frequency of MPs ingestion, mean values between 6 and 163 pg/g for PBDEs and 5-107 pg/g for HBCDs). Polyester fibers dominated among MP typologies, and a high occurrence of man-made natural fibers was recorded. The number of MPs extracted in the gastrointestinal tracts of fish and soft bodies of crayfishes positive to MPs ingestion ranged between 1 and 2, whereas no MPs were found in fish filets. Given these results, the risk related to human consumption of Trasimeno organisms appears very low, whereas further investigations are required to better elucidate the possible role of MPs pollution in modulating chemical bioaccumulation in edible tissues. This study contributed to assess both environmental quality and food safety, reinforcing the use of bioindicator species for monitoring plans, in accordance with European recommendations.

Microplastics accumulation in leaf litter: Field evidence for microplastic ingestion and transfer through prey-predatory relationships.

To combat the plastic problem in the marine environment, bioindicators are essential because they can provide insights into the extent and ecological impacts of plastic pollution. The ingestion and accumulation of microplastics (MPs) in the striped barnacle Amphibalanus amphitrite was studied by exposing them to MPs with or without biofilm. Three types (polyethylene, polystyrene/polyester), two sizes (27-32 µm and 90-106 µm) and two forms (microspheres and microfibers) of MPs at three concentrations (7.2, 72 and 720 P/mL) were investigated. The presence of biofilm did not affect the MP ingestion. The ingestion of MPs was concentration-dependent, irrespective of the size, form and type of the MPs. The numbers of microspheres and microfibers ingested by A. amphitrite were similar, and so were their numbers accumulated in the body. The results suggest a lack of both pre-ingestive and post-ingestive sorting and removal of MPs in A. amphitrite. The MP body burden, therefore, reflects levels of environmental contamination and the actual MPs composition in the water body. Considering the global distribution of A. amphitrite and its high abundance on rocky shores and man-made structures such as wharf piles, ease of finding and sampling, clear taxonomic status, small body size, high reproductive rate, specialized feeding mode, and well-known biology and life history, it has great potential to be considered as a member of a list of global marine bioindicators of MPs. Further investigations should focus on how seasonal changes in environmental factors and body conditions, such as reproductive cyclicity, influence the ingestion and accumulation of MPs, and the associated ecotoxicological effects.

Microplastic bioaccumulation in estuary-caught fishery resource

Microplastic accumulation in marine organisms across trophic levels along the west coast of India.

First evidence of ingestion and retention of microplastics in seahorses (Hippocampus reidi) using copepods (Acartia tonsa) as transfer vectors

Microplastics (MPs) have received increasing attention in the last decade and are now considered among the most concerning emerging pollutants in natural environments. Here, the current knowledge on microplastic ingestion by wild freshwater fish is reviewed with a focus on the identification of possible factors leading to the ingestion of MPs and the consequences on fish health. Within the literature, 257 species of freshwater fishes from 32 countries have been documented to ingest MPs. MPs ingestion was found to increase with rising level of urbanization, although a direct correlation with MPs concentration in the surrounding water has not been identified. MPs ingestion was detected in all the published articles, with MPs presence in more than 50% of the specimens analyzed in one study out of two. Together with the digestive tract, MPs were also found in the gills, and there is evidence that MPs can translocate to different tissues of the organism. Strong evidence, therefore, exists that MPs may represent a serious risk for ecosystems, and are a direct danger for human health. Moreover, toxicological effects have also been highlighted in wild catches, demonstrating the importance of this problem and suggesting the need for laboratory experiments more representative of the environmental situation.

Abundance, characteristics and variation of microplastics in different freshwater fish species from Bangladesh

Microplastics (MP) have been an evolving global concern by dint of the escalation of plastic pollution in the aquatic environment. However, few data document MP ingestion and accumulation in freshwater fauna as compared to marine organisms. This study investigates the prevalence of MPs in the gastrointestinal tracts (GIT) of 45 individuals belonging to seven commonly found Bangladeshi freshwater fish species with different feeding types (herbivore, carnivore, and omnivore). A total of 81 MP items of varying shapes were detected in 76% of individuals investigated, with an average abundance of 1.80±1.65 items/individual. Of these, fiber was identified as the most prevalent ingested MP type (70%) followed by film (14%), line (10%), fragment (4%), and foam (2%). Black-colored MPs were the most dominant (27%) followed by white (26%), blue (24%), red (17%), and green (6%). The results demonstrated a higher number of MPs in the carnivore (1.95 items/individual) and omnivore (1.85 items/individual) fish species as compared to herbivore fish species. Among carnivores, Wallago attu registered the highest amount of ingested MP items (3.5 items/individual), while Anguilla bengalensis registered the highest amount of ingested MP items (2.14 items/individual) among the omnivores. The amount of ingested MPs was significantly correlated (P<0.05) with body size, body weight, and gut weight, while an insignificant correlation (P>0.05) was found between the number of consumed MPs and trophic fractions. The results provide valuable insights into the prevalence of MPs in freshwater fish in Bangladesh and associated bioaccumulation through trophic transfer.

Microplastics (MPs) contamination in marine environments is of increasing concern, as plastic particles are globally ubiquitous across ecosystems. A large variety of aquatic taxa ingest MPs, but the extent to which animals accumulate and transfer MPs through food webs is largely unknown. In this study, we quantified MP uptake in bivalves, crabs, echinoderms, and fish feeding at different trophic levels at three sites on southern Vancouver Island. We paired stable-isotope food web analysis with MP concentrations in digestive tracts across all trophic levels and in fish livers. We then used Bayesian generalized linear mixed models to explore whether bioaccumulation and biomagnification were occurring. Our results showed that MPs (100-5000 μm along their longest dimension) are not biomagnifying in marine coastal food webs, with no correlation between the digestive tract or fish liver MP concentrations and trophic position of the various species. Ecological traits did, however, affect microplastic accumulation in digestive tracts, with suspension feeder and smaller-bodied planktivorous fish ingesting more MPs by body weight. Trophic transfer occurred between prey and predator for rockfish, but higher concentrations in full stomachs compared with empty ones suggested rapid excretion of ingested MPs. Collectively, our findings suggested the movement of MP through marine food webs is facilitated by species-specific mechanisms, with contamination susceptibility a function of species biology, not trophic position. Furthermore, the statistical methods we employ, including machine learning for classifying unknown particles and a probabilistic way to account for background contamination, are universally applicable to the study of microplastics. Our findings advance understanding of how MPs enter and move through aquatic food webs, suggesting that lower-trophic-level animals are more at risk of ingesting >100-μm MPs, relative to higher-trophic-level animals. Our work also highlights the need to advance the study of <100-μm MPs, which are still poorly understood and may need to be considered separately in ecological risk assessments.

Microplastic bioaccumulation in odonata larvae: Integrating evidence from experimental studies in freshwater microcosm.