Marine litter in stomach content of small pelagic fishes from the Adriatic Sea: sardines (Sardina pilchardus) and anchovies (Engraulis encrasicolus)

Uncovering microplastics contamination in canned seafood

There is limited research on the occurrence of microplastics (MPs) in canned seafood. All types of canned seafood investigated in the present study were contaminated. After sample digestion in 30 % hydrogen peroxide, a total of 40 MPs were recovered. Fibers were the most common type, blue was the dominant colour, and Fourier Transform Infrared Spectroscopy (FTIR) identified polyester as the most common polymer. Considering all samples, an average of 3.5 ± 5.2 MPs/can was obtained, with octopus in tomato sauce and tuna in olive oil presenting the highest contamination (5.2 ± 7.5 MPs/can and 5.2 ± 5.1 MPs/can, respectively). Also, significant differences between the number of MPs in the seafood tissues and immersion liquids were verified. The present study demonstrates MPs occurrence in canned seafood, a potential contamination pathway for humans. More research on the different stages of the canning processing is vital for understanding MPs contamination in cans.

Geographical and ecological factors affect microplastic body burden in marine fish at global scale

Microplastic (MP) contamination has been identified as a worrisome environmental issue at the global level. Fish are the taxonomic group more extensively investigated to assess MP contamination in marine environment. A large variability in MP bioaccumulation (i.e., body burden) was reported in fish but to date there is a dearth of information concerning the drivers underlying this process. The present systematic review aimed at summarizing the results of the scientific literature on MP body burden in the digestive tract of marine fish to quantitatively shed light on the contribution of different geographical (i.e., latitudinal origin of the sample, distance from the coastline and field- or marked-collected) and ecological (i.e., trophic strategy, milieu, and body size) factors driving bioaccumulation. The mean (±SE) MPs/individual was 4.13 ± 2.87, and the mean MPs/ww (i.e., MPs/g) was 5.92 ± 0.94. Overall, MP abundance expressed as MPs/individual of fish from tropical areas was significantly higher compared to the other latitudinal bands, with species sampled close to the coastline that accumulated a larger number of MPs compared to those collected offshore. Neither the trophic strategy, nor the milieu and the market or field origin of fish explained the MP body burden. However, fish body size resulted as a determinant of MP body burden (as MPs/individual), with small fish accumulating a lower amount of MPs compared to larger ones. Qualitatively, but not statistically significant, similar results were generally obtained for MPs/ww, except for an opposite, and significant, variation according to species body size. Our findings showed that geographical, rather than ecological factors represent the main drivers of MP body burden in marine fish, suggesting that environmental variables and/or local pollution sources mainly contribute to explaining the large variability underlying the ingestion and bioaccumulation processes of these contaminants.

New insights of bacterial and eukaryotic phenotypes on the plastics collected from the typical natural habitat of the endangered crocodile lizard

Although accumulating evidence indicates that endangered animals suffer from plastic pollution, this has been largely overlooked. Here, we explored the bacteria and eukaryotes living in the plastics gathered from the natural habitat of the highly endangered crocodile lizard. The results demonstrated that the bacterial and eukaryotic communities on plastics formed a unique ecosystem that exhibited lower diversity than those in the surrounding water and soil. However, microbes displayed a more complex and stable network on plastic than that in water or soil, implying unique mechanisms of stabilization. These mechanisms enhanced their resilience and contributed to the provision of stable ecological services. Eukaryotes formed a simpler and smaller network than bacteria, indicating different survival strategies. The bacteria residing on the plastics played a significant role in carbon transformation and sequestration, which likely impacted carbon cycling in the habitat. Furthermore, microbial exchange between plastics and the crocodile lizard was observed, suggesting that plastisphere serves as a mobile gene bank for the exchange of information, including potentially harmful substances. Overall, microbes on plastic appear to significantly impact the crocodile lizard and its natural habitat via various pathways. These results provided novel insights into risks evaluation of plastic pollution and valuable guidance for government efforts in plastic pollutant control in nature reserves.

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.

Marine litter weight estimation from UAV imagery: Three potential methodologies to advance macrolitter reports

In the context of marine litter monitoring, reporting the weight of beached litter can contribute to a better understanding of pollution sources and support clean-up activities. However, the litter scaling task requires considerable effort and specific equipment. This experimental study proposes and evaluates three methods to estimate beached litter weight from aerial images, employing different levels of litter categorization. The most promising approach (accuracy of 80 %) combined the outcomes of manual image screening with a generalized litter mean weight (14 g) derived from studies in the literature. Although the other two methods returned values of the same magnitude as the ground-truth, they were found less feasible for the aim. This study represents the first attempt to assess marine litter weight using remote sensing technology. Considering the exploratory nature of this study, further research is needed to enhance the reliability and robustness of the methods.

Microplastics in the stomach content of the commercial fish species Scomber colias in the Gulf of Cadiz, SW Europe

Concerning microplastics (MPs) contamination is increasing due their negative impacts on marine food webs and their potential toxicity to wildlife and humans. In this study, we analyze the presence of MPs in the stomachs of the commercial fish species Scomber colias (Atlantic chub mackerel) in the Gulf of Cadiz (GoC). Out of the 104 analyzed stomachs, 90.4 % contained some type of MPs, with an average of 5.4 MPs per individual. Of the 1152 MPs analyzed, 91.1 % were fibers, and 8.9 % fragments type. Fourier Transformation Infrared Spectrometry analysis was performed on 152 items, revealing that 73.6 % were MPs. The most common synthetic polymers found were polyamide (64 %), polypropylene (15 %), polystyrene (12 %), polyvinyl chloride (5 %), and polyethylene (4 %). The consistent ingestion of synthetic polymers by the individuals of Atlantic chub mackerel across different zones might suggest an even distribution of MP contamination throughout the GoC.

Review of emerging contaminants in green stormwater infrastructure: Antibiotic resistance genes, microplastics, tire wear particles, PFAS, and temperature

Green stormwater infrastructure is a growing management approach to capturing, infiltrating, and treating runoff at the source. However, there are several emerging contaminants for which green stormwater infrastructure has not been explicitly designed to mitigate and for which removal mechanisms are not yet well defined. This is an issue, as there is a growing understanding of the impact of emerging contaminants on human and environmental health. This paper presents a review of five emerging contaminants - antibiotic resistance genes, microplastics, tire wear particles, PFAS, and temperature - and seeks to improve our understanding of how green stormwater infrastructure is impacted by and can be designed to mitigate these emerging contaminants. To do so, we present a review of the source and transport of these contaminants to green stormwater infrastructure, specific treatment mechanisms within green infrastructure, and design considerations of green stormwater infrastructure that could lead to their removal. In addition, common removal mechanisms across these contaminants and limitations of green infrastructure for contaminant mitigation are discussed. Finally, we present future research directions that can help to advance the use of green infrastructure as a first line of defense for downstream water bodies against emerging contaminants of concern.

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

The accumulation of microplastics (MP) by marine species of ecological and commercial interest represents a major concern, particularly for those present in human diet. This study analysed the accumulation of MP in three species of coastal pelagic fish with high commercial value, European sardine (Sardina pilchardus), European anchovy (Engraulis encrasicolus) and horse mackerel (Trachurus trachurus), collected along the Western coast of the Iberian Peninsula. The gastrointestinal tract (GT), gills and muscle were analysed and a total of 504 particles were observed. MP were found in all target tissues of the studied species. Horse mackerel exhibited significantly higher concentrations of microplastics in GT compared to other tissues. On the other hand, anchovies and sardines had significantly lower microplastic concentrations in their muscle tissue. The accumulation of microplastics in the gills showed a significant difference between species, with anchovy having significantly higher concentrations compared to horse mackerel. Horse mackerel had the highest percentage of individuals with microplastics in their GT (92 %), followed by sardine (75 %) and anchovy (50 %). Horse mackerel was also the species that registered the highest percentage of individuals with particles in the muscle (63 %), followed by anchovy (40 %) and finally sardine (39 %). MP in the gills of European sardines and anchovies were similar to those found in water samples. The majority of MP found measured <0.5 mm and were blue fibers. Furthermore, the presence of MP in the GT showed a weak and moderated significant negative correlation with the Fulton Condition Index in horse mackerel and European sardine. Our study confirms the ubiquitous extent of MP contamination in the ocean and provides baseline evidence of MP tissue distribution in three small pelagic fish species with distinct feeding behaviour, while correlating this with the presence of MP in water. Importantly, the results of this study contribute to improve the understanding of biological partitioning of MP in open sea fish species with high commercial relevance, and the potential deleterious effects of our increasingly MP contaminated world.

Suspected anthropogenic microparticle ingestion by Icelandic capelin

Documented ingestion of microplastics and other anthropogenic microparticles (AMP) by marine fishes has increased over the last decade. However, baseline datasets on AMP ingestion in Arctic fish species are limited. This study documents AMP ingestion in Icelandic capelin (Mallotus villosus) and investigates how this relates to several biological variables. A total of 160 capelin gastrointestinal tracts were sampled and digested using 10 % potassium hydroxide and visual inspection protocols. A total frequency of occurrence (%FO) of 52.5 % and a mean AMP abundance of 1.33 ± 2.37 per individual was found (particles > 45 μm). The colour of AMP detected was significantly different between sampling locations. However, no differences in %FO or mean AMP abundance were detected between sampling locations or related to body size, gut fullness, or sex. This research contributes to the growing body of knowledge on AMP ingestion by Arctic marine species.

Microplastics, a Global Issue: Human Exposure through Environmental and Dietary Sources

Plastic production has grown dramatically over the years. Microplastics (MPs) are formed from the fragmentation of larger plastic debris by combining chemical, physical, and biological processes and can degrade further to form nanoplastics (NPs). Because of their size, MPs and NPs are bioavailable to many organisms and can reach humans through transport along the food chain. In addition to the risk from ingesting MPs themselves, there are risks associated with the substances they carry, such as pesticides, pathogenic microorganisms, and heavy metals, and with the additives added to plastics to improve their characteristics. In addition, bioaccumulation and biomagnification can cause a cumulative exposure effect for organisms at the top of the food chain and humans. Despite the growing scientific interest in this emerging contaminant, the potential adverse effects remain unclear. The aim of this review is to summarize the characteristics (size, shape, color, and properties) of MPs in the environment, the primary sources, and the transport pathways in various environmental compartments, and to shed more light on the ecological impact of MPs and the potential health effects on organisms and humans by identifying human exposure pathways.

Monthly microplastics change in European anchovy's (Engraulis encrasicolus) gastrointestinal tract in the Black Sea

To contribute to a better understanding of the regional dynamics of MP pollution and its potential effects on the anchovy population and human health, here we assessed the presence and characterization of microplastics (MPs) in European anchovy (Engraulis encrasicolus), which is the most caught/consumed species in the Black Sea and is of vital importance to the ecosystem. A total of 360 individuals (30 per month) were sampled from the eastern Black Sea continental shelf all year round (monthly from September 20 to Aug 21). We extracted and digested the gastrointestinal tracts (GITs) of the samples with H2O2 and characterized the MPs in the GITs by stereomicroscope and ATR-FTIR. MPs varied between 0 and 0.43 MP individual-1. The morphological structure of MPs was composed of 51 % fiber > fragment (32.7 %) > film (12.2 %) > foam (4.1 %) and polymer types as PP (42.9 %) and PE (22.4 %). In the prevalence of MP colors, black (26.5 %) > white (24.5 %) > red (22.5 %) was observed. The mean MP size was 735.32 ± 836.62 μm, with no significant correlation between the abundance and size of ingested MPs and anchovy height/weight and GIT weight. We determined that MP abundance showed substantial differences between the fishing season (0.18 ± 0.05 MP ind-1) and the banned season (0.05 ± 0.03 MP ind-1). It is essential to develop effective waste management strategies to protect the vulnerable marine ecosystems of the Black Sea and ensure sustainable exploitation of living resources in this region. These strategies should be accompanied by robust monitoring and enforcement measures to guarantee their effectiveness and compliance.

Trophic niche influences ingestion of micro- and mesoplastics in pelagic and demersal fish from the Western Mediterranean Sea

Plastic pollution has been extensively documented in the marine food web, but targeted studies focusing on the relationship between microplastic ingestion and fish trophic niches are still limited. In this study we investigated the frequency of occurrence and the abundance of micro- and mesoplastics (MMPs) in eight fish species with different feeding habits from the western Mediterranean Sea. Stable isotope analysis (δ13C and δ15N) was used to describe the trophic niche and its metrics for each species. A total of 139 plastic items were found in 98 out of the 396 fish analysed (25%). The bogue revealed the highest occurrence with 37% of individuals with MMPs in their gastrointestinal tract, followed by the European sardine (35%). We highlighted how some of the assessed trophic niche metrics seem to influence MMPs occurrence. Fish species with a wider isotopic niche and higher trophic diversity were more probable to ingest plastic particles in pelagic, benthopelagic and demersal habitats. Additionally, fish trophic habits, habitat and body condition influenced the abundance of ingested MMPs. A higher number of MMPs per individual was found in zooplanktivorous than in benthivore and piscivorous species. Similarly, our results show a higher plastic particles ingestion per individual in benthopelagic and pelagic species than in demersal species, which also resulted in lower body condition. Altogether, these results suggest that feeding habits and trophic niche descriptors can play a significant role in the ingestion of plastic particles in fish species.

Microplastics in Sepia officinalis caught on the central Adriatic coast: preliminary results

Microplastics (μPs) represent an emerging problem for the marine environment given their wide bioavailability for all aquatic organisms, from zooplankton to top predators. This work aimed to evaluate a method of extracting microplastics from the gastrointestinal tract of 122 Sepia officinalis caught from the Adriatic Sea (along Abruzzo region coasts) to measure its quantity in a poorly investigated species. The extraction method used for gastrointestinal content was performed using 10% potassium hydroxide. In 98/122 (80.32-95% CI=73.27-87.37%) wild animals microplastics were detected with a mean concentration of 6.82±5.52 μPs/subject. Among the fragments, as supported by various authors, those of black color were the most represented ones; however, also blue fibers and transparent spheres were isolated. This study, in agreement with previous ones, poses further attention to the wide microplastic diffusion in the marine environment (surface, columns, sediments, and animals). The obtained results provide the basis for future investigations on this public health concern.

The octopus pot on the North Atlantic Iberian coast: A plague of plastic on beaches and dunes

This baseline focuses on the octopus pot, a litter item found on the North Atlantic Iberian coast. Octopus pots are deployed from vessels in ropes, with several hundred units, and placed on the seabed, to capture mostly Octopus Vulgaris. The loss of gears due to extreme seas state, bad weather and/or fishing-related unforeseen circumstances, cause the octopus pots contaminating beaches and dunes, where they are transported by sea current, waves and wind actions. This work i) gives an overview of the use of octopus pot on fisheries, ii) analyses the spatial distribution of this item on the coast, and iii) discusses the potential measures for tackling the octopus pot plague on the North Atlantic Iberian coast. Overall, it is urgent to promote conducive policies and strategies for a sustainable waste management of octopus pots, based on Reduce, Reuse and Recycle hierarchical framework.

Impact of Fibrous Microplastic Pollution on Commercial Seafood and Consumer Health: A Review

The omnipresence of microfibers in marine environments has raised concerns about their availability to aquatic biota, including commercial fish species. Due to their tiny size and wide distribution, microfibers may be ingested by wild-captured pelagic or benthic fish and farmed species. Humans are exposed via seafood consumption. Despite the fact that research on the impact of microfibers on marine biota is increasing, knowledge on their role in food security and safety is limited. The present review aims to examine the current knowledge about microfiber contamination in commercially relevant fish species, their impact on the marine food chain, and their probable threat to consumer health. The available information suggests that among the marine biota, edible species are also contaminated, but there is an urgent need to standardize data collection methods to assess the extent of microfiber occurrence in seafood. In this context, natural microfibers should also be investigated. A multidisciplinary approach to the microfiber issue that recognizes the interrelationship and connection of environmental health with that of animals and humans should be used, leading to the application of strategies to reduce microfiber pollution through the control of the sources and the development of remediation technologies.

Sources, distribution, and incipient threats of polymeric microplastic released from food storage plastic materials

The present study aimed to find out the source, distribution, quantity, and incipient threats of the microplastics (MPs) released by food-packing plastic materials, plastic bags, bottles, and containers on human health, biodiversity, water bodies, and atmosphere. For this purpose, 152 articles about MPs (0.1 to 5000 µm) and nanoplastics (NP) 1 to 100 nm) were reviewed and interpreted their results in the present articles about microplastics. The highest plastic waste is generated by China (⁓ 59 Mt), the USA (⁓ 38 Mt), Brazil (⁓ 12 Mt), Germany (⁓ 15 Mt), and Pakistan (⁓ 6 Mt). The count of MPs (MPs/kg) in Chinese salt was 718, UK 136, Iran 48, and USA 32, while MPs in bivalves, i.e., in Chinese bivalves was 2.93, UK 2.9, Iran 2.2, and Italy 7.2 in MPs/kg, respectively. The MPs count in Chinese fish was 7.3, Italy's 23, the USA's 13, and UK's 1.25 in MPs/kg, respectively. The MP concentrations in the water bodies, i.e., USA, were 15.2, Italy 7, and UK 4.4 in mg/L, respectively. It was critically reviewed that MPs can enter the human body causing various disorders (neurotoxic, biotoxic, mutagenic, teratogenic, and carcinogenic disorders) because of the presence of various polymers. The present study concluded that MPs were released from processed and stored food containers, either through physical, biological, or chemical means, which harshly affect the surrounding environment and human health. The study recommended that alternatives to plastic containers are glass and bioplastic containers, papers, cotton bags, wooden boxes, and tree leaves need to use to avoid direct consumption of MPs from food.

Tropical sharks feasting on and swimming through microplastics: First evidence from Malaysia

Plastic can be degraded into microplastic (<5 mm) and has been polluting worldwide marine environment and negatively impact human health. Microplastics in marine organisms are still understudied in Malaysia, let alone from a subclass Elasmobranchii. Five tropical shark species (Carcharhinus dussumieri, Carcharhinus sorrah, Chiloscyllium hasseltii, Chiloscyllium punctatum, and Scoliodon laticaudus) were examined for the presence of microplastics. 74 sharks were sampled from the local wet market and 100 % of samples contained microplastics. A total of 2211 plastic particles were found in gastrointestinal tracts (GIT) and gills, where 29.88 ± 2.34 particles per shark (mean ± SEM). Black (40.07 %) and fiber (84.44 %) microplastics were the most dominant. Extracted microplastic sizes ranged from 0.007 mm to 4.992 mm. This study suggests that microplastic uptake is gender-related for some shark species. A subsample of microplastics (10 %) was used for polymer type identification, where polyester was recorded the highest (43.95 %).

Detection methods of micro and nanoplastics

Plastics and related contaminants (including microplastics; MPs and nanoplastics; NPs) have become a serious global safety issue due to their overuse in many products and applications and their inadequate management, leading to possible leakage into the environment and eventually to the food chain and humans. There is a growing literature reporting on the occurrence of plastics, (MPs and NPs) in both marine and terrestrial organisms, with many indications about the harmful impact of these contaminants on plants and animals, as well as potential human health risks. The presence of MPs and NPs in many foods and beverages including seafood (especially finfish, crustaceans, bivalves, and cephalopods), fruits, vegetables, milk, wine and beer, meat, and table salts, has become popular research areas in recent years. Detection, identification, and quantification of MPs and NPs have been widely investigated using a wide range of traditional methods, such as visual and optical methods, scanning electron microscopy, and gas chromatography-mass spectrometry, but these methods are burdened with a number of limitations. In contrast, spectroscopic techniques, especially Fourier-transform infrared spectroscopy and Raman spectroscopy, and other emerging techniques, such as hyperspectral imaging are increasingly being applied due to their potential to enable rapid, non-destructive, and high-throughput analysis. Despite huge research efforts, there is still an overarching need to develop reliable analytical techniques with low cost and high efficiency. Mitigation of plastic pollution requires establishing standard and harmonized methods, adopting holistic approaches, and raising awareness and engaging the public and policymakers. Therefore, this chapter focuses mainly on identification and quantification techniques of MPs and NPs in different food matrices (mostly seafood).

Impacts of nano/micro-plastics on safety and quality of aquatic food products

The spread of nano/microplastics (N/MPs) pollution has gained importance due to the associated health concerns. Marine environment including fishes, mussels, seaweed and crustaceans are largely exposed to these potential threats. N/MPs are associated with plastic, additives, contaminants and microbial growth, which are transmitted to higher trophic levels. Foods from aquatic origin are known to promote health and have gained immense importance. Recently, aquatic foods are traced to transmit the nano/microplastic and the persistent organic pollutant poising hazard to humans. However, microplastic ingestion, translocation and bioaccumulation of the contaminant have impacts on animal health. The level of pollution depends upon the pollution in the zone of growth for aquatic organisms. Consumption of contaminated aquatic food affects the health by transferring the microplastic and chemicals. This chapter describes the sources and occurrence of N/MPs in marine environment, detailed classification of N/MPs based on the properties influencing associated hazard. Additionally, occurrence of N/MPs and their impact on quality and safety in aquatic food products are discussed. Lastly, existing regulations and requirements of a robust framework of N/MPs are reviewed.

Mistaking plastic for zooplankton: Risk assessment of plastic ingestion in the Mediterranean sea

Floating plastic debris is a pervasive pollutant in seas and oceans, affecting a wide range of animals. In particular, microplastics (<5 mm in size) increase the possibility that marine species consume plastic and enter the food chain. The present study investigates this potential mistake between plastic debris and zooplankton by calculating the plastic debris to zooplankton ratio over the whole Mediterranean Sea. To this aim, in situ data from the Tara Mediterranean Expedition are combined with environmental and Lagrangian diagnostics in a machine learning approach to produce spatially-explicit maps of plastic debris and zooplankton abundance. We then analyse the plastic to zooplankton ratio in regions with high abundances of pelagic fish. Two of the major hotspots of pelagic fish, located in the Gulf of Gabès and Cilician basin, were associated with high ratio values. Finally, we compare the plastic to zooplankton ratio values in the Pelagos Sanctuary, an important hotspot for marine mammals, with other Geographical Sub-Areas, and find that they were among the larger of the Western Mediterranean Sea. Our results indicate a high potential risk of contamination of marine fauna by plastic and advocate for novel integrated modelling approaches which account for potential trophic transfer within the food chain.

Dried fish more prone to microplastics contamination over fresh fish - Higher potential of trophic transfer to human body

Globally, microplastics (MPs) contamination in aquatic organisms is emerging as an alarming phenomenon. In the present study, we investigated MPs in three commercially important fishes (Bombay duck Harpadon nehereus, ribbon fish Trichiurus lepturus and hairfin anchovy Setipinna phasa) in fresh and dried conditions collected from two sites (Chattogram and Kuakata) of the Bay of Bengal. It was evident that fresh T. lepturus ingested highest amount of MPs through the gills (6.41 mps/g) from Chattogram followed by in the gastrointestinal tract, GIT (6.20 mps/g) and in the muscle (1.20 mps/g) from Kuakata. Among the fresh fishes, H. nehereus from Kuakata accumulated highest amount of MPs (0.21 mps/g), while S. phasa from Kuakata contained the least amount of MPs (0.06 mps/g). On the other hand, among the dried fishes, T. lepturus from Kuakata contained highest amount of MPs (46.00 mps/g), while S. phasa from Kuakata retained lowest amount of MPs (2.17 mps/g). Strangely, all the dried fishes showed significantly higher amount of MPs compared to fresh fishes from both the locations. Fiber was the most dominant type of shape of MPs which accounted 66 %, followed by fragment (27.38 %), microbeads (3.59 %), film (1.48 %), foam (1.31 %) and pellet (0.25 %). Size-wise, the major portion (39.66 %) of MPs was present to be in size range less than 0.5 mm followed by 37.67 % in the size range of 0.5-1.0 mm group and rest 22.67 % within 1.0-5.0 mm. Red (41.55 %) colored MPs was the most prominent, followed by brown (22.11 %), blue (16.32 %), pink (11.69 %), purple (5.10 %), and green (2.25 %). Among polymer types, low-density polyethylene (LDPE) was the most common (38 %), followed by polystyrene (PS-22 %), polyvinyl chloride (PVC-16 %), polyamide (PA-13 %) and ethylene-vinyl acetate (EVA-9 %). The present study confirms high occurrence of MPs in the dried fishes over the fresh fishes from the Bay of Bengal, with high potential of trophic transfer to the human body.

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 Fish and Fishery Products and Risks for Human Health: A Review

In recent years, plastic waste has become a universally significant environmental problem. Ingestion of food and water contaminated with microplastics is the main route of human exposure. Fishery products are an important source of microplastics in the human diet. Once ingested, microplastics reach the gastrointestinal tract and can be absorbed causing oxidative stress, cytotoxicity, and translocation to other tissues. Furthermore, microplastics can release chemical substances (organic and inorganic) present in their matrix or previously absorbed from the environment and act as carriers of microorganisms. Additives present in microplastics such as polybrominated diphenyl ethers (PBDE), bisphenol A (BPA), nonylphenol (NP), octylphenol (OP), and potentially toxic elements can be harmful for humans. However, to date, the data we have are not sufficient to perform a reliable assessment of the risks to human health. Further studies on the toxicokinetics and toxicity of microplastics in humans are needed.

Ascaridoid parasites in European sardine throughout the annual cycle: Variability in parasitic load according to host stock features

In recent years, a drop in the condition of the European sardine has been observed. Although several causes have been attributed to this issue, as overfishing and climate change, little is known about the link between ascaridoid nematode parasitisation and fish status. In this study, sardines were obtained from four fishing grounds along the Mediterranean (Alboran, Northern Spain, Northern Adriatic, and Aegean), and one location in the Atlantic Ocean (Southern Portugal). After analysing individual fish body condition (by direct tissue fat content measurements and condition indices), and reproductive status (by a detailed gonadal examination) throughout the entire annual cycle, ascaridoids were recognised by combining naked eye and UV-press method along flesh, viscera, and gonads. Afterwards, sequence analysis of the rDNA internal transcribed spacers region (ITS) and the mtDNA cox2 gene were used to identify and characterise the different species of ascaridoids from the fish host in the localities throughout the seasons. The main species found along different areas was Hysterothylacium aduncum, present in the Northern Adriatic (prevalence of 7.6%, mean intensity 1.700), the Atlantic (7.5%, 3.889), and the Northern Spain (3.9%, 1.600). Moreover, few individuals of Anisakis simplex (s.s.) and A. pegreffii were observed in the Atlantic (1.7% and 0.8%, respectively), and the latter species was also found in the Adriatic stock (0.8%). All ascaridoid specimens were found in viscera. Obtained results seem to indicate that in stocks with medium sizes, small variations in length are related to parasite intensity. This study highlights the importance of seasonal parasitological analyses at stock level and, especially, in capital breeders, as relationships between condition and reproduction parameters and parasitism are conditioned by seasonality.

A Biomarker Approach as Responses of Bioindicator Commercial Fish Species to Microplastic Ingestion: Assessing Tissue and Biochemical Relationships

Plastic debris is a growing environmental problem on a global scale, as plastics and microplastics (MPs) can be ingested by marine organisms, inducing toxic effects. The aim of this study was to assess MP intake and antioxidant responses in three bioindicator species: red mullet, bogue, and anchovy (Mullus surmuletus, Boops boops, and Engraulis encrasicolus, respectively) for plastic contamination in the Mediterranean Sea. MP intake was assessed in the gastrointestinal tract of the fish. Further, several enzymes from both the liver and brain were analysed. The antioxidant defences, catalase (CAT) and superoxide dismutase (SOD), as well as the detoxifying enzyme glutathione-S-transferase (GST), were measured in both tissues. The acetylcholine esterase (AchE), as an indicator of neuronal damage, was measured in the brain. Malondialdehyde (MDA) was analysed as a marker of oxidative damage in the brain and liver samples. Total MP intake and MP typology differed between the three species, with M. surmuletus showing the lowest intake of MPs, while B. boops showed the highest intake of MPs. An increase in both antioxidant enzymes was evidenced in E. encrasicolus liver activity with respect to MP intake. In brain samples, an increase in CAT activity was found in M. surmuletus and B. boops as a consequence of MP ingestion. SOD activity in the brain increased in B. boops and E. encrasicolus that had ingested MPs. GST activity increased in the liver of M. surmuletus' and in brains of B. boops that had ingested MPs. The intake of MPs is species related, as well as being inherently linked to the habitat they live in and being able to induce a light activation of species-specific detoxifying and antioxidant mechanisms.

Microplastics accumulation in gastrointestinal tracts of Mullus barbatus and Merluccius merluccius is associated with increased cytokine production and signaling

There is clear evidence that different marine species can be impacted by microplastic (MP) ingestion accumulating such MPs mainly in the gastrointestinal tract. However, there is still limited knowledge on the consequences of MPs' accumulation in the gut. The present study aims to assess MPs and their potential immunotoxic effects in the digestive tract of two species showing different ecological traits: the red mullet (Mullus barbatus) and the European hake (Merluccius merluccius). Infrared spectroscopy (FTIR-ATR), micro-Raman and electron scanning microscope (SEM) were used to accurately identify the main plastic polymers detected in gut contents. In addition, we investigated the association between MP uptake and intestinal inflammation by evaluating expression and secretion of proinflammatory cytokines. MP abundance ranged from 1 to 20 items/individual in red mullet and from 2 to 15 items/individual in European hake. The majority of ingested MPs were fibers, while the dominant colors were black and blue in both species. Chemical characterization indicated polyethylene and polypropylene as the most common polymer types. Moreover, it was observed that MP abundance was highly positive correlated to cytokines (i.e. interleukin-1β, 10, and interferon) and antioxidant enzyme (i.e. catalase and superoxide dismutase) transcript levels suggesting ROS generation and an infiltration of immune cells in the gut. Our findings provide evidence that the induction of cytokine-dependent signaling pathways is one aspect of the complex mechanism by which MPs affect the gut system in fish.

Assessment of the health status of the European anchovy (Engraulis encrasicolus) in the NW Mediterranean Sea from an interdisciplinary approach and implications for food safety

The European anchovy (Engraulis encrasicolus) is a small pelagic fish with an outstanding commercial value supporting important fisheries and is a key component of pelagic ecosystems in the Mediterranean Sea. Progressive reductions in the population size of this species has been observed in the Mediterranean Sea during recent decades, accompanied by a decline in the body condition, as well as the size/age of maturation. Nonetheless, the health status has not been yet assessed using a holistic approach. Herein, we analyse the health status of the European anchovy, integrating distinct indicators from fish condition, enzymatic biomarkers, presence of tissue alterations, and parasite descriptors. In addition, we analyse the presence of anthropogenic items (AIs) in the digestive tract of fish and their potential impact on health status. Additionally, we assess the differences between current AIs values and those recorded over 12 years ago. None of the health indicators studied provided evidence of relevant pathologic conditions affecting this fish species in the studied area. However, changes in the pattern of liver parenchyma were found. Compared with anchovy populations from other distribution areas, no zoonotic parasites were recorded in this study, demonstrating a reduced risks associated with foodborne transmission to humans. AIs, such as fibres and plastic particles, were found in the digestive tract of half of the fish analysed. A significant increase was detected in AIs prevalence between 2007 (40 %) and 2019 (70 %), alongside differences in the abundance and typology of the AIs, though this does not seem to have impacted fish health yet. Therefore, our work underscores the importance of implementing a regular program to monitor the health status of this key species to better understand population dynamics and their drivers.

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.

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 detection of microplastics in Xyrichtys novacula (Linnaeus 1758) digestive tract from Eivissa Island (Western Mediterranean)

Plastic waste and its ubiquity in the oceans represent a growing problem for marine life worldwide. Microplastics (MPs) are ubiquitous in the sea and easily enter food webs. Xyrichtys novacula L. is one of the main target species of recreational fishing in the Balearic Islands, Spain. In the present study, the quantity of MPs in gastrointestinal tracts of X. novacula from two different areas (a marine protected area (MPA) and a non-protected area) of Eivissa Island (in the Balearic archipelago) has been assessed, as well as MPs evaluation within the sediment of both areas. The results showed that over 80% of sampled individuals had MPs in their gut with an average of 3.9 ± 4.3 plastic items/individual. Eighty percent of these plastics were fibres, while the rest were fragments. Although the sediment of the non-protected area had a significant higher presence of MPs, no significant differences in the number of MPs were observed in X. novacula from both areas. The µ-FT-IR analysis showed that the main polymers in the sediments were polycarbonate (PC) and polypropylene (PP), whereas in the digestive tract of fish PC, PP, polyethylene, polystyrene and polyester. In conclusion, practically all X. novacula specimens presented MPs in their digestive tract regardless if the capture zone was in a MPAs or not. These results highlight the ubiquity of MPs in coastal marine areas, and further studies might be necessary to evaluate further implications of MP presence in this species.

Seafloor litter generated by coastal and offshore fisheries operations in the South Sea of Korea

Seafloor litter sources, distribution and density were assessed in a bottom trawl survey of the South Sea around Jeju Island by the Ara-ho training ship of Jeju National University. Samples were taken from 14 transects at a depth range of 60-120 m in areas with sandy and muddy substratum. Generally, mean densities varied from 26.9 items/km² to 62.4 items/km² and 104.8 kg/km² to 370.9 kg/km². Mean densities of total litter sampled was 46.3 items/km² and 228.6 kg/km². Derelict gears were the most common litter items (92 % of total litter) with mean densities of 44.3 items/km² and 228.1 kg/km². Gillnets and traps were the most derelict with densities reaching 4.9 items/km² and 99.2 kg/km² and 25.0 items/km² and 89.1 kg/km² respectively. The results of this study indicate that significant level of pollution in the South Sea are generated from commercial fishing activities and gillnets and traps being high risk derelict gears.

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.

Color preferences and gastrointestinal-tract retention times of microplastics by freshwater and marine fishes

We examined ingestion and retention rates of microplastics (MPs) by two freshwater (Japanese medaka and zebrafish) and two marine fish species (Indian medaka and clown anemonefish) to determine their color preferences and gastrointestinal-tract retention times. In our ingestion experiments, clown anemonefish ingested the most MP particles, followed by zebrafish, and then Japanese and Indian medaka. Next, we investigated color preferences among five MP colors. Red, yellow, and green MP were ingested at higher rates than gray and blue MPs for all tested fish species. To test whether these differences truly reflect a recognition of and preference for certain colors based on color vision, we investigated the preferences of clown anemonefish for MP colors under light and dark conditions. Under dark conditions, ingestion of MP particles was reduced, and color preferences were not observed. Finally, we assessed gastrointestinal-tract retention times for all four fish species. Some individuals retained MP particles in their gastrointestinal tracts for over 24 h after ingestion. Our results show that fish rely on color vision to recognize and express preferences for certain MP colors. In addition, MP excretion times varied widely among individuals. Our results provide new insights into accidental MP ingestion by fishes.

Plastic in digestive tracts and gills of cod and herring from the Baltic Sea

Plastic litter is widespread on our planet and is recognized as a contaminant of high concern. Plastic ingestion and retention in gills were studied in two key Baltic fish species: herring (Clupea harengus L.) and cod (Gadus morhua L.). In total, 183 fish from the southern Baltic Sea were analysed. Plastic litter was found in digestive tracts of 12.7 and 14.8% of herrings and cods, respectively. In addition, gills were shown to constitute an important transfer route of plastic to cod (9.9% of cods) but not to herring thus likely reflecting species-specific differences in fish lifestyles and/or water filtering capacity. No more than one plastic item per individual was found except for three fish with two items in their stomachs. Dominant microplastics (<5 mm) (MPs) (88.6% of all items) composed of irregular fragments, fibres and foils (61.3%, 25.8% and 12.9% of all MPs, respectively) were followed by meso- (5-25 mm) and macro-plastics (>25 mm) (5.7% each of all items). Plastic ingestion and retention in gills did not affect fish body condition assessed by Fulton's K index, although herrings that ingested plastic particles beyond the microplastic size range (i.e. >5 mm) were characterized by the lowest condition indices. All plastic items recovered from fish exhibited clear signs of weathering and surface extended due to their roughness and fragmentation which may enhance both sorption properties for chemical compounds and/or their leaching. Nevertheless, chemical contaminant levels in herring muscles were not different than in a plastic-free group. The vast majority of fibres found in fish was identified as air-borne or procedural contamination and were excluded from further analyses. In addition, the vessel's paint dust found in fish stressed the need for strict quality assurance also during fish sampling.

Microplastics in the Deep: Comparing Dietary and Plastic Ingestion Data between Two Mediterranean Bathyal Opportunistic Feeder Species, Galeus melastomus, Rafinesque, 1810 and Coelorinchus caelorhincus (Risso, 1810), through Stomach Content Analysis

Marine plastic pollution is currently an issue of mounting concern around the world. Stomach content of marine fish has been increasingly used as a valid proxy for detecting the presence of such a pollutant in marine biota, both for coastal and deep-water environments. Although ingestion of microplastics has been reported in an increasing number of species, the patterns of ingestion still remain unclear, depending closely on the interaction between the species and types of microplastics involved. In this context, we analysed and compared the stomach contents of two bathyal dwelling opportunistic feeder species namely Galeus melastomus and Coelorinchus caelorhincus. In particular, we analysed microplastic items according to their dimension, morphology and colour, and diet’s variation with size obtained through prey identification. Both species showed a higher frequency of occurrence of the blue filament-like middle-sized microplastics (1.01–4.75 mm) compared with the other categories, although this pattern was much more marked in C. caelorhincus than in G. melastomus. The latter conversely showed a larger array of ingested plastic items in terms of shape and colour. Matching plastic ingestion with dietary data suggested potential predator confusion occurring in C. caelorhincus through active mis-selection of a defined type of microplastic instead of some particular family of polychaetes, which resemble in shape, size, and color to that type. Otherwise, G. melastomus appeared more prone to a random ingestion of a larger array of microplastic items because of a more generalistic and less selective feeding strategy. Although further validation is needed, stomach contents of the two species showed evidence strong enough to be considered as potential bioindicator species of microplastic pollution, as required by the Marine Strategy Framework Directive for monitoring this pollutant in the marine environment.

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.

Ingestion of microplastics by commercial fish species from the southern Black Sea coast

Microplastic (MP) contamination is a serious threat to today's marine life. Therefore, this study investigates MP ingestion in three commercial fish species (European anchovy Engraulis encrasicolus, whiting Merlangius merlangus, and red mullet Mullus barbatus) from the Turkish coast of the Black Sea. Ninety-five MPs were detected in all examined fish (371). Fiber forms were detected in the majority of cases based on the MP morphology. Polyethylene and polypropylene were the most dominant polymer type. The mean of ingested MPs was found as 0.15 ± 0.04, 0.28 ± 0.06, 0.40 ± 0.07 in anchovy, whiting and red mullet, respectively. The size of the MPs ranged from 118 μm and 4854 μm. The MP waste was detected in each species, and the highest MP amount was determined in the red mullet, which was significantly higher than European anchovy. The present study's data might be a baseline on the ecological risk assessment of MPs in the fish and future experimental studies on the fish species living in the Black Sea.

Additives, plasticizers, small microplastics (<100 μm), and other microlitter components in the gastrointestinal tract of commercial teleost fish: Method of extraction, purification, quantification, and characterization using Micro-FTIR

One of the aims of this study is the development of a pretreatment method for additives, plasticizers and other components of micro-litter (APFs), and small microplastics (SMPs <100 μm) in the gastrointestinal tract (GIT) of five of the most widely distributed and consumed commercial fish species, Engraulis encrasiculos, Sardina pilchardus, Mullus surmuletus, Solea solea, and Sparus aurata. The second aim was to develop a simultaneous quantification and identification method via Micro-FTIR of APFs and SMPs ingested by these commercial fish species. The distribution of SMPs and APFs is characteristically different for each species investigated. E. encrasiculos and S. pilchardus had a higher weight of SMPs than the other species investigated. Regarding APFs, the highest abundance was observed in E. encrasiculos. This study highlights the importance of studying additives and plasticizers that can be used as efficient proxies of microplastics, as shown by the presence of vulcanizing agents such as Vanax®.

Microplastic accumulation in commercial fish from the Adriatic Sea

We assessed the presence and concentration of microplastics in fishes from the Northern Adriatic Sea on sale for human consumption. Microplastics were extracted from the digestive tract of 180 specimens, belonging to 6 different species (2 pelagic, and 4 demersal). Microplastics were identified through Nile red staining, and selected particles were analyzed by μ-Raman spectroscopy. The 47.8% of examined fish were found to contain microplastics (233 fragments). The mean concentration of microplastics in the 6 species ranged between 4.11 ± 2.85 items/individual in Adriatic soles, and 1.75 ± 0.71 items/individual in pilchards. Microplastics ranged in size between 0.054 mm and 0.765 mm. Polyethylene and polypropylene were the polymer types identified through μ-Raman spectroscopy. Despite our estimates are underestimations, these results are of particular concern, as the fish analyzed are consumed without being eviscerated, and the microplastics they contain are transferred directly to humans.

Untoward Effects of Micro- and Nanoplastics: An Expert Review of Their Biological Impact and Epigenetic Effects

The production of plastic has dramatically increased in the last 50 y. Because of their stability and durability, plastics are ubiquitously incorporated in both marine and terrestrial ecosystems. Plastic is acted upon by biological, chemical, and physical agents, leading to fragmentation into small pieces [i.e., microplastics (MPs) or nanoplastics (NPs)], classified depending on their size. MPs range from 0.1 to 5000 μm and NPs are fragments between 0.001 to 0.1 μm. MPs and, especially NPs, are easily incorporated into living beings via ingestion. The penetration of MPs and NPs into the food system is an important issue, for both food security and health risk assessment. Ingestion of different MPs and NPs has been associated with different issues in the intestine, such as direct physical damage, increased intestinal permeability, diminished microbiota diversity, and increases in local inflammatory response. However, the potential harmful effects of low-dose dietary plastic are still unclear. Some evidence indicates that intestinal uptake of plastic particles is relatively low and is mostly dependent on the particle's size. However, other evidence highlights that NPs dysregulate key molecular signaling pathways, modify the gut microbiota composition, and may induce important epigenetic changes, including transgenerational effects that might be involved in the onset of many different metabolic disorders. Until now, experiments have been mostly performed on marine organisms, Caenorhabditis elegans, and mouse models, but some research indicates accidental plastic dietary consumption by humans, raising the issue of detrimental health effects of MPs and NPs. This review discusses the impact that MPs and NPs could have on the intestinal tract and the biodistribution and systemic, cellular, and molecular levels. Accumulated evidence of MPs' effects on the human gut suggests that large exposure to MPs and NPs may have phenotypical untoward effects in humans, calling for urgent research in this field.

Microplastic contamination of fish gills and the assessment of both quality assurance and quality control during laboratory analyses

Microplastic pollution has received substantial international attention in terrestrial and marine environments and in the atmosphere. In this study, we assessed microplastic pollution and analyzed the accumulation of microplastics in the gills of fish caught in the Zhoushan fishing ground from September 2017 to March 2018. The average abundance of microplastics was 0.49 ± 0.54 particles/gill and frequently found chemical polymers was polyethylene terephthalate. We also conducted experiments on microplastic pollution in the water and the working solutions used during the analytical process and found that the source of microplastic contamination was the solutions used. Moreover, we evaluated and scored experimental quality control and quality assurance adapted from the 'Total Accumulated Score' method. Valuable steps are recommended in order to produce reliable results and improve the quality of results in microplastic analyses.

Occurrence of potential plastic microfibers in mussels and anchovies sold for human consumption: Preliminary results

There is a global concern over the impact of microplastics on marine species and trophic webs. Microfibers commonly represent the greater portion of microplastics in the aquatic environment, but little is known about fiber uptake and accumulation by marine biota. The aim of the study was to investigate the potential plastic microfiber contamination in mussels (Mytilus galloprovincialis) and anchovies (Engraulis encrasicolus) from the Tyrrhenian Sea sold for human consumption. Anthropogenic debris was extracted from the digestive tracts of fish and the whole shellfish using a 10% KOH solution and quantified under a light microscope. The preliminary results showed the occurrence of potential plastic and natural microfibers in 73% of the samples. On average mussels contained 1.33 microfibers/g w.w. and 7.66 items/individual, while anchovies contained 9.06 microfibers/individual. Considering that mussels are consumed as a whole, and small pelagic fish, as anchovy, may be eaten without removing the gastrointestinal tract, microfiber contamination may lead to human exposure. More research is required to adequately assess the risk that microplastics, including microfibers, may pose for food safety and human health.

Environmental status of marine plastic pollution in Spain

The excessive use of plastic in our society is causing a massive accumulation, since it is a non-biodegradable product and with still poor recycling rates. This effect can be observed in the seas, which more and more plastic waste are accumulating. The present work is a critical review, based on all currently available literature, that reports environmental status of marine plastic pollution, especially microplastic pollution, in Spain. The three Spanish water areas with the highest presence of plastics are the Alboran Sea, the Gulf of Alicante and the vicinity of Barcelona probably related to fishing and industrial activities and high population densities. With regard to microplastic contamination on beaches in Spain, annual monitoring by the Spanish government shows contamination along the entire coast of the country, with particularly high concentrations in the Canary Islands (between 800 and 8800 particles/m² in spring). Between 40 and 50% of the particles analyzed were pellets and the main factors postulated for the distribution of these particles are marine currents and the geomorphological characteristics. With regards to biota, ingestion of microplastics by fish has been intensely confirmed and, important differences were observed between the locations of the sampling, being bogues (Boops boops) one of the fish species more studied in Spain. Finally, the work includes a revision of European and Spanish legislation about plastics and marine pollution and some strategies to reduce this kind of contamination in Spain.

Microplastics in aquatic environments: A review on occurrence, distribution, toxic effects, and implications for human health

Microplastics (MPs) are fragments, fibers, granules, flakes and spheres with a diameter or length of less than 5 mm. These may eventually end up in the aquatic environment by the progressive breakdown of larger plastics or via domestic and industrial sewage spillage. In order to better understand the current knowledge in this field, we carried out and extensive literature research to retrieve articles mainly focusing on the occurrence and distribution of MPs in aquatic matrix as well as their impacts on aquatic organisms and human derived cells. Once in the environment, MPs may be transported via wind and water movement, affecting their spatial distribution. Furthermore, density may also affect the buoyancy and vertical distribution of these pollutants. Consequently, MPs are ubiquitously distributed in fresh- and marine- water systems, posing a real threat to aquatic organisms. Furthermore, trophic transfer and biomagnification processes represent a viable route for the input of MPs to humans. This paper focuses on (1) Outline the occurrence of MPs in worldwide aquatic ecosystems; (2) Investigate the factors affecting the abundance and distribution of MPs in aquatic ecosystems; (3) Provide an in-depth discussion about the harmful effects that MPs poses to aquatic organisms; (4) Summarizes the possible mechanisms by which MPs may induce toxic effects on humans.

Evidence of microplastic ingestion by cultured European sea bass (Dicentrarchus labrax)

The presence of microplastics (MPs) in the marine environment is a concerning topic due to the ecotoxicological effects and possible seafood contamination. Data is needed to evaluate human exposure and assess risks, in the context of a healthy and beneficial seafood consumption. While microplastic ingestion by wild fish has been reported since the early 70's, farmed fish are rarely investigated. Here, for the first time the presence of microplastics in fish cultivated in the coastal water of Tenerife (Canary Island, Spain) was evaluated. From 83 examined individuals, 65% displayed microplastics in their gastrointestinal tracts, with averages between 0.6 ± 0.8 (SD) and 2.7 ± 1.85 (SD) particles per fish. The total number of microplastics detected was 119. Fibres (81%) and fragments (12%) were the predominant shapes. FTIR analysis showed that fibres were mostly composed by Cellulose (55%) and Nylon (27%), whereas fragments by PE (25%) and PP (25%).

How do humans recognize and face challenges of microplastic pollution in marine environments? A bibliometric analysis

Microplastics (MPs) are abundant in marine environments, drawing global attention from scientists and rendering it significant to review the research progress and predict future trends of this field. To achieve that, we collected 1898 publications on marine MPs from Web of Science and performed a bibliometric analysis by CiteSpace and VOSviewer. Additionally, we utilized an unrestricted retrieval of literature from ScienceDirect to supplement our major findings. Trends in publication numbers show the growth in study from the initial stage ( 2012 and before), when microplastic (MP) occurrence, abundance, and distribution were primarily investigated. Throughout the ascent stage (between 2013-2016), when diverse sampling and analytical methods were applied to capture and identify MPs from the ocean, baseline data have been gleaned on physiochemical properties of MPs. The research focus then shifted to the bioaccumulation and ecotoxicological effects of MPs on marine biota, further highlighting their potential deleterious impacts on human health via dietary exposure, and this period was defined as the exploration stage (2017 and onwards). Nevertheless, key challenges including the lack of standard procedures for MP sampling, technical limitations in MP detecting and identification, and controversy about the underlying effects on the marine ecosystems and humans have also been arisen in the last decade. The present study elucidates how we gradually recognize MP pollution in marine environments and what challenges we face, suggesting future avenues for MP research.

Microplastics contamination in food and beverages: Direct exposure to humans

Since microplastics (MPs) bring the potential risks to human health when plastics are ingested, more needs to be known about the presence and abundance of human ingestion of MPs. To address these issues, we reviewed 108 publications in Web of Science concerning abundances, sources, and analytical methods of MPs in human daily intake including fish, salt, drinking water, beverages, package food, and other food. The results demonstrate that aquatic food products (fish and bivalves) present a wide range of 0-10.5 items/g for bivalves and 0-20 items/individual for fish. Salt data in literatures present a concentration of 0-13,629 particles/kg. Drinking water is also a pathway of MPs exposure to human, presenting a concentration range from 0 to 61 particles/L for tap water and 0 to 6292 MPs/L for bottled water. Besides, MPs have been found in beverages, package food, sugar, honey, vegetables, and fruits. Therefore, human intake of MPs via ingestion is a nonnegligible exposure route.

Plastic Ingestion by the Small-Spotted Catshark (Scyliorhinus canicula) from the South West Coast of the United Kingdom

Plastic pollution has increased dramatically worldwide and is having a detrimental effect on a variety of marine organisms. This study contributes to the existing data on the ingestion of both macroplastics and microplastics by one elasmobranch species, the small-spotted catshark (Scyliorhinus canicula), considering the occurrence in males and females. Plastics were extracted from the stomach and spiral valve of (N = 200, n = 100 females and n = 100 males) and analysed by visual observations. A total of 28 pieces of plastic were found with five pieces extracted from a single individual. Overall findings indicate that this shark species is vulnerable to some extent to plastic ingestion (6.5% frequency of occurrence), but different aspects, such as differences in plastic contamination levels of different locations and ability to regurgitate stomach content, may affect the results of similar studies.

Preliminary results on the occurrence and anatomical distribution of microplastics in wild populations of Nephrops norvegicus from the Adriatic Sea

This study reports the shapes, dimensional classes, types and counts of microplastics (MPs) found in 23 individuals of N. norvegicus collected from two wild populations of the Adriatic Sea (Mediterranean basin). The focus was on three different anatomical compartments (gut, hepatopancreas and tail), which were analysed separately. MPs were found in all the investigated individuals with an average of about 17 MPs/individual. Fragments were predominant over fibers with a ratio of about 3:1. The majority of MPs were in the dimensional range 50-100 μm. The predominant polymers were polyester, polyamide 6, polyvinyl chloride and polyethylene, which together constitute about 61% of all the MPs found. Fragments were more concentrated in the hepatopancreas, with no significant difference between gut and tail, while fibers were more concentrated in the gut than in the tail with hepatopancreas somehow in between. The dimensional class of the MPs influences their anatomical distribution. There were no statistical differences among individuals from the two sampling sites. Sex of the individual did not influence the level of retained MPs, while length had a very marginal effect. The information reported here contributes to understanding of the possible risks linked to human consumption of different tissues from contaminated Norway lobsters.