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

Occurrence of microplastics in the gastrointestinal tracts of four most consumed fish species in Giresun, the Southeastern Black Sea

Microplastic studies investigating concentrations in water are numerous, but the majority of microplastics settle and are retained in sediment, and higher concentrations are regularly reported in sediments. Thus, MPs accumulation may be more threatening to benthic fish living in sediments than to pelagic fish. The presence, abundance and diversity of microplastics were investigated by collecting samples from two pelagic, European anchovy, and horse mackerel and two benthic fish species, red mullet, and whiting that are popularly consumed in Giresun province of Türkiye, located on the southern coast of the Black Sea. Visual classification and chemical compositions of microplastics was performed using a light microscope and ATR-FTIR spectrophotometry, consecutively. The overall incidence and mean microplastics abundance in sampled fishes were 17 and 1.7 ± 0.18 MP fish-1, respectively. MPs were within the range of 0.026-5 mm in size. In most of the cases, the MP was black in color with 41%. With the rates of 56%, polypropylene was the predominant polymer type. The most dominant MP type was identified as fiber followed by fragments and pellets. The relationship between MP amounts in fish and Fulton condition factor was not strong enough to establish a cause-effect relationship.

Microplastics in multi-environmental compartments: Research advances, media, and global management scenarios

During the past decades, microplastics (MPs) have become an emerging concern due to their persistence and potential environmental threat. MP pollution has become so drastic that it has been found in the human food chain, breast milk, polar regions, and even the Himalayan basin, lake, etc. Inflammation, pulmonary hypertension, vascular occlusions, increased coagulability and blood cell cytotoxicity, disruption of immune function, neurotoxicity, and neurodegenerative diseases can all be brought on by severe microplastic exposure. Although many MPs studies have been performed on single environmental compartments, MPs in multi-environmental compartments have yet to be explored fully. This review aims to summarize the muti-environmental media, detection tools, and global management scenarios of MPs. The study revealed that MPs could significantly alter C flow through the soil-plant system, the structure and metabolic status of the microbial community, soil pH value, biomass of plant shoots and roots, chlorophyll, leaf C and N contents, and root N contents. This review reveals that MPs may negatively affect many C-dependent soil functions. Different methods have been developed to detect the MPs from these various environmental sources, including microscopic observation, density separation, Raman, and FT-IR analysis. Several articles have focused on MPs in individual environmental sources with a developed evaluation technique. This review revealed the extensive impacts of MPs on soil-plant systems, microbial communities, and soil functions, especially on water, suggesting possible disturbances to vital ecological processes. Furthermore, the broad range of detection methods explored emphasizes the significance of reliable analytical techniques in precisely evaluating levels of MP contamination in various environmental media. This paper critically discusses MPs' sources, occurrences, and global management scenarios in all possible environmental media and ecological health impacts. Future research opportunities and required sustainable strategies have also been suggested from Bangladesh and international perspectives based on challenges faced due to MP's pollution.

The presence and physico-chemical properties of microplastics in seawater, sediment, and several organs of the spotted scat fish (Scatophagus argus, Linnaeus, 1766) collected from different locations along the East Java coast in Indonesia

A comprehensive study was undertaken to examine the contamination of spotted scat fish (Scatophagus argus) with microplastics (MP) in various locations along the East Java coast of Indonesia. The purpose of this study was to collect detailed information regarding the abundance, color, shape, size, type of polymer, and chemical components of the MP. The findings of this study indicated that MP exhibiting distinct attributes-including a specific fiber type, black coloration, and a size range of 1000- <5000 μm-was most abundant in the gill, stomach, and intestines of spotted scat fish of varying lengths. And MP with a size range of 100-<500 μm was prevalent in the sediment. MP with black fragments measuring less than 100 μm in diameter were found primarily in seawater. A positive correlation was identified between fish length and MP abundance in the intestines, as indicated by the Spearman correlation coefficient. Conversely, a negative correlation was detected between fish length and MP abundance in the gills. The findings of the Fourier transform infrared spectroscopy and Gas chromatography-mass spectrometry analyses, which indicate the presence of various polymers and chemical substances including plasticizers (e.g., diethyl phthalate, decane, and eicosane), stabilizers (2-piperidinone, hexadecanoic acid, mesitylene, and 2,4-Di-tert-butylphenol), and flame retardant (cyclododecene), in fish, are of the utmost importance. These substances have the potential to endanger the health of both animals and humans if they are ingested through the food chain.

Assessment of the impact of microplastic ingestion in striped red mullets from an Eastern Mediterranean coastal area (Zakynthos Island, Ionian Sea)

Monitoring microplastics (MPs) in the marine environment is an ongoing process, and our understanding of their impact on marine organisms is limited. The present study evaluates the effects of ingested MPs on the marine MP pollution bioindicator fish species Mullus surmuletus. The study follows a three-fold approach to assess the impact of MPs on marine organisms by investigating: 1) the ingestion of MPs, 2) the bioaccumulation of phthalate compounds as plastic additives, and 3) the evaluation of toxicological biochemical and cellular biomarkers. Striped red mullets were sampled in the marine protected area (MPA) of the National Marine Park of Zakynthos and coastal sites with high touristic pressure in Zakynthos Island in the Ionian Sea, Greece. Fewer ingested MPs and lower phthalate concentrations were found in fish inside the MPA compared to those sampled outside the marine park. However, no relationship was found between either phthalate concentrations or biomarker levels with the ingested MPs in the red striped mullets. Biomarker levels were influenced by season and site, but no effect could be attributed to the ingested MPs. The lack of association of biomarker responses and plasticizer bioaccumulation to MP ingestion can be explained by the low number of ingested MPs in the fish from Zakynthos coastal area as MP abundance ranged from 0.15 to 0.55 items per individual fish.

Use of trophic ecology of omnivorous fish and abiotic factors as supporting tools for assessing environmental impacts in a neotropical river

The study of diet is one of the mechanisms by which competition for resources between species that cohabit in the same ecosystem can be inferred. Therefore, the relationships of the indices that measure specialization in the diet of fish species are necessary to characterize the nutritional quality of these populations and the ecosystem's environmental health. Three species of catfish were selected: one invasive (Clarias gariepinus) and two natives (Trachelyopterus striatulus and Rhamdia quelen), with similar distribution along the Guapi-Macacu River, in the Guapimirim Protection Area (Rio de Janeiro). Fifty-nine catfish of the three species were collected in total, along 32 collection points in the Guapi-Macacu River in two periods (dry and rainy) in 2018. Non-parametric statistics showed the partition of resources between species and the influence of abiotic factors (temperature, pH, transparency, and dissolved oxygen) contributing to the selection of available resources in the environment. Diet-related indices-repletion index (RI), condition factor (K), niche width, and trophic position (TP) of the specimens collected-contributed to measuring the nutritional status of each of these catfish species, showing that R. quelen has a relationship between RI and K, tending to absorb and metabolize nutrients faster than other species. In addition, the invasive species occupies a wide range of TPs compared to native species, confirming its feeding plasticity. On the contrary, T. striatulus needs large amounts of terrestrial insects to maintain its poor condition factor. Also, the RI showed direct influences of abiotic variables, with the temperature being the most prominent. Our results suggest that the invasive species can benefit from this environment that shows signs of environmental degradation.

Beadlet anemone: A novel bio-indicator of microplastic pollution in the marine environment

Extensive usage of plastic in different industries and household usage has degraded to microplastic due to environmental conditions over the last year. While several researchers conducted the determination of microplastic (MP) bioaccumulation from rivers to stormwater, except for some filter-feeding species used as a bioindicator, to achieve a holistic approach to the fate of MPs in the marine system, sea anemone was used as an indicator. Microplastics were extracted from surface seawater, sediment, and sea anemones from the same sampling area and characterized. The extracted MPs were confirmed by confocal micro-Raman spectroscopy, and the morphology of the MPs was investigated by scanning electron microscopy (SEM). The results showed that the accumulation of microplastics and the type of polymer, shape, colour, and size of these persistent pollutants varied in sediment, surface water, and sea anemone. The abundance of MPs was different, and grey-coloured MPs were detected at a relatively higher level in sea anemones, from 8.7 to 13.3%, and more minor MPs (less than 0.5 mm) at 43.4-56.8% were detected in sea anemones among the sampling stations. In terms of polymer type, there are relatively more types of polymers classified in sea anemones among the sampling stations (six different types of polymers). These results indicated that the utilization of sea anemones as a bioindicator for MPs could be a critical factor in a better understanding of their pathway in the marine ecosystem. This study proved that analysing sea anemones as an indicator could offer a reliable, fast, and time-saving approach for detecting microplastic accumulation in marine systems.

Microplastic enrichment capacity of Ctenochaetus striatus from the habitat environment - An example in Xisha, South China Sea

Microplastic pollution is a widespread concern in the global marine environment. In this study, microplastic pollution status in Xisha waters was investigated. Microplastics were found in all seawater samples, and 90.76 % of C. striatus samples were detected with microplastics. The average abundance of microplastics in seawater samples was 0.64 ± 0.39 items/L, and the abundance of microplastics in the gills and gastrointestinal tracts (GITs)of C. striatus was 1.14 ± 0.41 items/L and 1.80 ± 0.49 items/L, respectively. Shapes of microplastics in the seawater and in the gills and GITs of C. striatus were mainly fibers and films, and the majority of the particle sizes being <1 mm, and the polymers were mainly PET. In addition, the abundance of microplastics in the gills and GITs of C. striatus was positively correlated with that in the seawater, and the correlation was higher in the gills than in the GITs, which means that the accumulation of microplastics in the gills was more closely related to their habitats. The positive correlation between microplastic abundance in the gills and GITs of C. striatus and its body size may be due to the fact that larger individuals have greater energetic demands, require more energy requirements, consume more food, and thus increase the chances of ingesting microplastics.

Plastic Contamination in Seabass and Seabream from Off-Shore Aquaculture Facilities from the Mediterranean Sea

We characterized the presence of plastics in different organs of the gilthead seabream (Sparus aurata) and European seabass (Dicentrarchus labrax) from some off-shore aquaculture facilities of the Mediterranean Sea. Plastics were detected in 38% of analyzed fish. Higher contamination was observed in fish from Turkey and Greece with respect to Italy, without significant differences between the geographical areas. Plastics accumulated mostly in the gastrointestinal tract and, to a lower extent, in the muscle, which represents the edible part of fish. Based on the particle detected, a maximum amount of 0.01 plastic/g wet weight (w.w.) can occur in muscles, suggesting a low input for humans through consumption. A large portion of the particles identified was represented by man-made cellulose-based fibers. The characterization of the polymeric composition suggests that plastics taken up by fish can have land-based and pelagic origins, but plastics can be introduced also from different aquaculture practices.

The Presence of Microplastics in the Gills and Gastrointestinal Tract of Mackerel (Rastrelliger Kanagurta Cuvier, 1816) from Jakarta Bay, Indonesia

This study examined the characteristics of microplastics (MPs) in the gills and gastrointestinal tract (GIT) of mackerel (Rastrelliger kanagurta) captured in Jakarta Bay, Indonesia. All 120 fish contained MPs, with fragment > fiber > film being the most prevalent types, in that order. The total abundances of fragments, fibers, and films in the gills were as follows: 4.8 ± 1.6, 1.0 ± 0.7, and 0.3 ± 0.3, respectively. The total abundances of fragments, fibers, and films in the GIT were 5.9 ± 2.3, 1.3 ± 0.8, and 0.4 ± 0.4, respectively. Statistical analysis showed that the abundance of fragments, fibers and films in both the gills and GIT of mackerel did not differ significantly between sampling locations. In the gills and GIT, MPs with sizes less than 0.1 mm and MPs that were black in color were most prevalent. Fourier transform infrared (FTIR) spectroscopy tests on MPs from the tissues of mackerel showed that there were 8 different types of MP polymers, namely, latex, nylon, polymethyl methacrylate (PMMA), cellulose acetate (CA), polyurethane (PU), polycarbonate (PC), polystyrene (PS), and polytetrafluoroethylene (PTFE). Latex and polycarbonate were detected in fish samples from Jakarta Bay.

Detection of anthropogenic fibres in marine organisms: Knowledge gaps and methodological issues

Most studies examining the occurrence of plastics and microplastics in marine organisms have identified anthropogenic fibres, of natural and synthetic origin, as the most commonly occurring category. Anthropogenic fibres may have been chemically treated with additives making them more persistent and a potential threat to marine organisms. However, fibres have often been excluded from analytical data for the difficulties related to the sampling and analytical procedures, including potential overestimation of the results due to airborne contamination. This review aimed to collect and analyse all studies focusing on the interaction between anthropogenic fibres and marine organisms worldwide, highlighting critical issues that need to be overcome for the analysis fibres on marine organisms. Furthermore, emphasis was placed on the species studied in the Mediterranean Sea, which is particularly affected by this type of pollution. Overall, this review shows that fibre pollution is an underestimated threat to marine organisms and that a specific, harmonised protocol for the analysis of different anthropogenic fibres needs to be developed.

First account of microplastics in pelagic sporting dolphinfish from the eastern Mexican coast of Baja California Sur

This study is a baseline data on the presence of MPs from the gastro-intestinal tracts (GITs) in Coryphaena hippurus Linnaeus, from eastern Baja California Sur, México. 878 MPs items (in %) of fibers (29%), fragments (68%) and films (1.3%) were detected from 51 GITs of Coryphaena hippurus. Transparent, white, blue and black were the prevalent colours. Morphological features observed through SEM analysis, the presence of heavily weathered MPs is due to the mechanical, microbiological and chemical weathering process. PP (29%), Nylon (29%), PS (17%), PE (11%), PET (6%) and HDPE (8%) presence indicates their source from regional anthropogenic stress. Trophic level transition is enforced by polymer derivative, permitting the sinking behavior of MPs and increased ingestion probability. Fishes were classified as slim despite their higher feeding capabilities and ingested MPs indicates a relationship with environmental contaminants. Current study emphasizes the health risk linked to biological aspects of MPs ingestion.

Euryhaline fish larvae ingest more microplastic particles in seawater than in freshwater

Microplastic (MP) pollution is a major concern in aquatic environments. Many studies have detected MPs in fishes; however, little is known about differences of microplastic uptake by fish in freshwater (FW) and those in seawater (SW), although physiological conditions of fish differ significantly in the two media. In this study, we exposed larvae (21 days post-hatching) of Oryzias javanicus (euryhaline SW) and Oryzias latipes (euryhaline FW), to 1-µm polystyrene microspheres in SW and FW for 1, 3, or 7 days, after which, microscopic observation was conducted. MPs were detected in the gastrointestinal tracts in both FW and SW groups, and MP numbers were higher in the SW group in both species. Vertical distribution of MPs in the water, and body sizes of both species exhibited no significant difference between SW and FW. Detection of water containing a fluorescent dye revealed that O. javanicus larvae swallowed more water in SW than in FW, as has also been reported for O. latipes. Therefore, MPs are thought to be ingested with water for osmoregulation. These results imply that SW fish ingest more MPs than FW fish when exposed to the same concentration of MPs.

Presence of microplastic in the Patella caerulea from the northeastern Mediterranean Sea

This study reports first evidence of microplastic detection in the Patella caerulea collected from 5 different stations located in İskenderun Bay and Mersin Bay. A total of 160 P. caerulea specimens were examined and 40 of them contained MPs in their soft tissues. The number of microplastics extracted per sample varied from 0.20 ± 0.5 items/ind to 0.45 ± 0.7 items/ind depending on station. Fibers were predominant type of MPs and accounted for 75 % to 87.5 % of total extracted MPs, followed by fragments (12.5-25 %). Majority of MPs were 0.5-1 mm size and black in color. Fourier transform infrared spectroscopy (FTIR) showed that the extracted MPs were polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET), high density polyethylene (HDPE). This study contributes to the knowledge of the transfer of microplastics to the marine food web and highlights the need for protective measurements.

Are microplastics contributing to pollution-induced neurotoxicity? A pilot study with wild fish in a real scenario

Pollution-induced neurotoxicity is of high concern. This pilot study investigated the potential relationship between the presence of microplastics (MPs) in the brain of 180 wild fish (Dicentrarchus labrax, Platichthys flesus, Mugil cephalus) from a contaminated estuary and the activity of the acetylcholinesterase (AChE) enzyme. MPs were found in 9 samples (5% of the total), all of them from D. labrax collected in the summer, which represents 45% of the samples of this species collected in that season (20). Seventeen MPs were recovered from brain samples, with sizes ranging from 8 to 96 μm. Polyacrylamide, polyacrylic acid and one biopolymer (zein) were identified by Micro-Raman spectroscopy. Fish with MPs showed lower (p ≤ 0.05) AChE activity than those where MPs were not found. These findings point to the contribution of MPs to the neurotoxicity induced by long-term exposure to pollution, stressing the need of further studies on the topic to increase 'One Health' protection.

Disturbing ion regulation and excretion in medaka (Oryzias melastigma) gills by microplastics: Insights from the gut-gill axis

The accumulation of microplastics (MPs) in fish gills has been widely recognized, however, whether such stress could thereby impact the physiological responses of fish gills is still unknown. Here, we investigated the impacts of three sizes (400 nm, 4 μm, 20 μm) of polystyrene (PS) MPs on (Na⁺, K⁺, Cl^-) ions regulation and ammonia excretion in medaka Oryzias melastigma. Significantly increased net Na⁺ and K⁺ flux rates were observed transiently during 0-3 h and 3-9 h, but not during 9-24 h. Such results suggest that the physiological resilience of fish gills regarding Na⁺ and K⁺ regulation was unaffected upon the exposure to PS-MPs, probably evidenced by the increased secretion of mucus. However, Cl^- regulation and ammonia excretion were significantly impaired, partly in consistent with the damages of ionocytes. The adverse impacts of PS-MPs on Cl^- regulation and ammonia excretion were size-dependent, with significant disturbances observed in 4 μm and 20 μm treated group for Cl^- regulation, but only in 20 μm treated group for ammonia excretion. The specific enrichment of Shinella and lower abundance of function profiles related to ion transport and metabolism might be responsible for the specific disturbance of Cl^- regulation found in the 4 μm treated group. The enrichment of Gemmobacter also accounted for the disturbances of ammonia excretion in 20 μm treated group. Our results highlighted the impacts of PS-MPs on the physiological functions in fish gills.

Detection of microplastic fibers tangle in deep-water rose shrimp (Parapenaeus longirostris, Lucas, 1846) in the northeastern Mediterranean Sea

Microplastic (MP) pollution in marine environments has been a major global concern in recent years. Microplastic particles pose a threat in aquatic animals by accumulating in their digestive system, acting like a pollution vector, and they can also transfer to upper trophic levels. For that reason, commercially important deep-water rose shrimp Parapenaeus longirostris were employed in this study to examine the MP pollution status of two different regions (Samandağ and Mersin offshore waters) of the northeastern Mediterranean Sea. MPs were detected in all examined specimens (average of 18.8 MPs ind-1), and fiber tangle-shaped like balls were observed by 22% and 9% at Samandağ and Mersin, respectively. P. longirostris individuals from Samandağ showed higher occurrence (100%) and higher accumulation (29.7 ± 24.4 MPs ind-1). MP abundance extracted from the shrimp individuals from Samandağ region was higher than that of previously reported shrimp species. The majority of extracted microplastics were fiber (100%), black (46%) in color and 1-2.5 mm in size. Polyethylene was identified as the most common polymer type by Fourier transform infrared spectroscopy (FTIR). This study is the first report to evaluate microplastic occurrence and fiber tangles in P. longirostris from northeastern Mediterranean Sea. Results obtained in this study will enhance the understanding of MP pollution among different trophic levels.

Microplastics in water surface and in the gastrointestinal tract of target marine organisms in Salento coastal seas (Italy, Southern Puglia)

Microplastic pollution is a major global environmental threat that has attracted increasing interest from the scientific community over the past decade. The semi-closed and highly urbanized Mediterranean Sea has been investigated since 2012, in several specific studies that have identified it as a target hotspot for microplastic contamination. The marine coastal zone of the Salento peninsula (Apulia, Italy) has peculiar geographical and hydrodynamic features, although there are few published data detailing the level of microplastics present in this area. The present manuscript contains both data on the concentration of microplastics in surface waters and the level of microplastics ingested by selected marine organisms in the Salento coastal zone. Microplastics floating on the water surface were monitored during Autumn 2020 and Spring 2021 using neuston Manta net at three different distances from the coasts (Lizzano, Gallipoli and Otranto). The level of microplastic ingestion was monitored in fish species (Sardina pilchardus, Boops boops, Mullus barbatus) and in mussels (Mytilus galloprovincialis). Episodic peaks of microplastic concentrations were found on the sea surface during transects performed in the 3 nautic miles from the seashore. High values of ingested microplastics were found in S. pilchardus. and B. boops (5.4 and 4.6 items/individual respectively). A higher concentration of microplastics was detected in the Adriatic Sea than in the Ionian Sea by comparing the gastrointestinal tract of S. pilchardus and B. boops, in the monitored areas. These results are correlated with the concentration of floating microplastics, although this last result is not validated by statistical analysis. These results support the effectiveness of S. pilchardus and B. boops used as targets in monitoring activity for these pollutants. Results show a worrying increase in the concentration of microplastics on the sea surface and in the gastrointestinal tract of the target species compared to data reported in the literature.

Microplastics in fish and sediments from the Montenegrin coast (Adriatic Sea): Similarities in accumulation

The accumulation of microplastics (MPs) in the biotic and abiotic components of the marine environment poses a major threat to marine ecosystems worldwide. The objective of this study was to document, for the first time, differences in MP accumulation in the gastrointestinal tract of two commercially important fish species and to evaluate the possible correlation between MP accumulation in the biotic (fish) and abiotic (sediment) components of the marine environment of the Montenegrin coast (Adriatic Sea). Samples were collected from two areas of the Montenegrin coast, Boka Kotorska Bay and the coastal part of the open sea. The frequency of MP ingestion was 58.6 % for Mullus barbatus and 54 % for Merluccius merluccius, while the average number of ingested MPs was 2.9 ± 0.5 and 3.2 ± 1.0 items/individual, respectively. Average MP abundance in surface sediments from Boka Kotorska Bay and the coastal part of the open sea was 315 ± 45 and 435 ± 258 MPs/kg of dry sediment, respectively. Most MPs identified were filaments, followed by fragments and films, while the most abundant polymers found in fish and sediments samples were polypropylene and polyethylene. The present results indicate that MP pollution in the study area is reflected in the accumulation of MPs in the biotic (fish) and abiotic (sediment) components of the marine environment. Measures need to be taken to reduce the input of plastics/MPs into the marine environment.

Microplastic ingestion evidence by economically important farmed fish species from Turkey

Microplastic pollution and its potential impacts on humans become a global concern. This study is the first study examining the microplastic ingestion in the commercially important species Oncorhynchus mykiss Rainbow trout (Walbaum, 1792), Sparus aurata Gilthead seabream Linnaeus, 1758, and Dicentrarchus labrax European seabass (Linnaeus, 1758) from Turkey. The occurrence frequency of microplastic (MP)in the gastrointestinal tract (GIT) was varied between 50 and 63 %. The highest MP abundance in the GIT was estimated in Rainbow trout (1.2 MPs individual^-1) followed by European seabass (0.95 MPs individual^-1) and Gilthead seabream (0.8 MPs individual^-1). Most of the extracted microplastic particles were black (61 %) and blue (27 %) in color and fiber (80 %) in shape. Major identified polymers were polyethylene (25 %), polyester (20 %), polyamide (10 %). Since fish consumption is an important route for MPs, results light up the danger potential for humans. This study will fill the information gap in Turkey and show the necessity of protection measures in aquaculture industry.

First record of microplastic occurence at the commercial fish from Orontes River

Freshwater environments are more sensitive to anthropogenic influences and usually contain higher concentrations of pollutants than marine environments. Microplastic pollution causes additional stress on freshwater animals; yet, studies evaluating the microplastic occurrence in freshwater biota are still limited. In this study, microplastic occurrence in the gastrointestinal tracts (GIT) and gill of commercial fish species (Prussian carp Carassius gibelio (Bloch, 1782); Abu mullet Planiliza abu (Heckel, 1843); Common carp Cyprinus carpio Linnaeus, 1758; European ell Anguilla Anguilla (Linnaeus, 1758); North African catfish Clarias gariepinus (Burchell, 1822); Goldfish Carassius auratus (Linnaeus, 1758) were reported from Orontes River. MPs abundance in the GIT and gill of six species were found as 5.1 ± 2 MPs fish^-1 and 4.4 ± 2 MPs fish^-1 with an occurrence of 95% and 74%, respectively. The majority of extracted microplastics were fiber, black and less than 1000 μm in size. FTIR analysis determined the main polymer types as polyester (50%), high-density polyethylene (HDPE) (10%), polypropylene (PP) (8%) and polyethylene terephthalate (PET) (5%). High MPs abundance and frequency of occurence indicate the exposure of microplastic pollution in freshwater biota which could threat the health of both individuals and consumers. Results obtained in this study will increase the acknowledgement of MPs pollution in the Orontes River. Also, this study will provide data to the administrators to set up necessary legislations in freshwater ecosystems.