Average Abundance Of Microplastics Research Articles

The presence of microplastics in fishes of South Maldives

Plastic pollution has been a widespread global challenge with negative impacts on human health, environment and economies. Recently its effect on the environment and marine life has been of immense interest. This study aimed to investigate the presence of microplastics in the gut, gill and flesh of Selar Crumenophthalmus and Decapterus Macarellus from two different locations in South Maldives. A total of 56 fishes were examined from the two species and a total of 200 possible microplastic pieces were identified by visual analysis. It was found that 80% of Selar Crumenophthalmus contained micro and macroplastics, whereas these were detected in 76.2% of Decapterus Macarellus. The average abundance of microplastics in fishes was 3.3 ± 4.6 items/individual and in both species, the abundance of microplastics was highest in the gills compared to other body parts with an average abundance of 1.4 ± 2.1 items/individual. The ingested plastics mainly consisted of fragments (57.5%), fibres (41.5%) and films (1%). The particles which were identified from the analysed samples predominantly included blue (36.90%), grey (30.48%), black (17.11%) and red (9.09%) colours. The ingested plastics were found to be polyethylene (PE) and polypropylene (PP), which were determined with the use of Fourier Transform Infrared (FT-IR) Spectroscopy.

Analysis of Microplastics in Water and Biofilm Matrices in Lahor Reservoirs, East Java, Indonesia

One of the aquatic ecosystems that are very susceptible to contamination is the reservoir ecosystem. Reservoirs have different characteristics from other water bodies because they receive continuous water input from the river that flows through them. The river water contains organic and inorganic materials that can cause pollution caused by various kinds of human activities. The pollutant that is currently getting more attention is microplastics. Hence, various ways are developed to monitor the presence of microplastics in environments. The biotic component that may adsorb and accumulate microplastics is microbes that formed biofilm matrices as a predominant habitat. This study analyzes the presence of microplastics in water and biofilm matrices in Lahor Reservoir. The water parameters (pH, dissolved oxygen, temperature, and flow velocity) were also measured. Samplings were carried out at three stations, namely station A (inlet channel), station B (middle), and station C (outlet channel). This study revealed that water quality parameters were still relatively good according to the environment's quality standards. The average value of microplastic abundance in water at station A was 0.0013 particles.mL-1, station B was 0.00083 particles.mL-1, and station C was 0.00072 particles.mL-1. The average abundance of microplastics in the biofilm at station A, station B, and station C was 7.55 particles.g-1, 7.26 particles.g-1, and 4.59 particles.gram-1, respectively. This study indicates that the abundance of microplastics in the biofilm in the Lahor Reservoir was thousands of times higher than in the water. According to the results of this study, the biofilm can be used as a biological agent in monitoring the presence of microplastics in aquatic ecosystems such as the Lahor Reservoir, East Java, Indonesia. Keywords: Aquatic Ecosystem, Biofilm, Microbial Ecology, Microplastics, Water Pollutant.

Greenhouse farming as a source of macroplastic and microplastics contamination in agricultural soils: a case study from Southeast-Hungary

Greenhouse plastic contaminations in agricultural soils were studied to quantify and examine the macroplastic and microplastic contaminants on the soil surface, soil profile, and groundwater under greenhouse farmland. Random sampling was used to select three areas in a greenhouse farm where macroplastic and microplastic data were collected. Four composite samples were collected from shallow (0–20 cm) and deep (20–40 cm) soils for each sampling point, respectively. Three soil profiles were dug, and samples were collected at intervals of 20 cm. Groundwater samples were also collected from the same profiles at a depth of 100 cm. Microplastics were extracted using predigestion of organic matter with 30% H2O2 and density separation with ZnCl2. The total mass of macroplastics in the greenhouse farmland was 6.4 kg ha–1. Polyethylene and polyvinyl chloride were the dominant plastic structures, and the dominant sizes were 1–5 and 0.5–1.0 cm, respectively. Overall, the average abundance of microplastics in the greenhouse soil was 225 ± 61.69 pieces/kg, and the dominant size structure was 2–3 mm. The average microplastic concentrations at depths of 0–20 and 20–40 cm were 300 ± 93 and 150.0 ± 76.3 pieces/kg, respectively. The average microplastic concentration in the groundwater was 2.3 pieces/l, and fibers were the dominant plastic structure. Given that microplastics were found in greenhouse soil, soil profiles, and groundwater, we recommend the careful cleaning and disposal of plastics on greenhouse farmland and further research to shed light on the level of microplastic contamination in the soil profiles and groundwater.

Microplastic pollution in the surface water and sediments from Kallar Kahar wetland, Pakistan: occurrence, distribution, and characterization by ATR-FTIR.

This study reports the distribution of microplastics in surface water and sediments collected from Kallar Kahar wetland, Punjab, Pakistan, which is a game reserve and hosts migratory birds during winter season. Microplastics were extracted using density separation and wet oxidation method. The microplastics identification was done under a stereo-microscope, and their polymer compositions were characterized using an attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The average abundance of microplastics in water and sediment samples was 88 ± 14.5 items/Land 5720 ± 2580 items/kg, respectively. The dominant shape groups of microplastics in water were fiber (58.7%), irregular fragments (32.4%), and beads (8.7%) with dominant colors as transparent > black > yellow ≈ white > red > green > pink > blue. Similar distribution in sediments was found, i.e., fiber (61.2%), irregular fragments (28.4%), and beads (10.3%) with dominant colors as transparent > pink > white > red ≈ black > blue > brown > green ≈ yellow. The ATR-FTIR spectra of visible microplastics were identified to be polypropylene (PP), high density polyethylene (HDPE), ethylene vinyl acetate (EVA), low density polyethylene (LDPE), nitrile, polymethyl methacrylate (PMMA), latex, and polyethylene terephthalate (PETE). In the study area, recreational activities, improper waste disposal, and runoff from catchment areas are the main reasons for the contamination of microplastics in the Lake. The pollution load can be minimized by taking measures such as creating awareness, promotion of ecotourism, and reducing plastic use.

Microplastics contamination in bivalves from the Daya Bay: Species variability and spatio-temporal distribution and human health risks

Microplastic contamination is an emerging global threat for various marine organisms. Marine invertebrates such as bivalve mollusks are more susceptible to the widespread presence of microplastics due to their limited abilities to escape from pollution exposure and they can readily ingest environmental pollutants like microplastics through their filter-feeding behaviors. In this study, microplastic contamination in bivalves related to species, spatial, and temporal variability were conducted. Results showed that the frequency of microplastic occurrence varied from 86.7 % to 93.3 % in six species of bivalves, and the average abundance of microplastics ranged from 3.5 to 8.6 items per individual or from 0.2 to 3.1 items per gram tissues wet weight. No significant difference was observed in microplastic abundances of bivalves collected from different research regions and sampling seasons. However, the sediment-dwelling bivalves had higher microplastics abundances than the water-dwelling bivalves. Microplastic features with various shapes, colors, sizes, and polymer types detected in bivalves were similar with those in seawater and sediment environments that they are living in. The potential risk assessment of microplastics in bivalves basing on polymer hazard index (PHI) was in the risk levels of II-III, implying that microplastic contamination in bivalves may pose health risk to human via seafood consumption.

Characteristics of Microplastics and Their Affiliated PAHs in Surface Water in Ho Chi Minh City, Vietnam.

Microplastic pollution has become a worldwide concern. However, studies on the distribution of microplastics (MPs) from inland water to the ocean and their affiliated polycyclic aromatic hydrocarbons (PAHs) are still limited in Vietnam. In this study, we investigated the distribution of MPs and PAHs associated with MPs in canals, Saigon River, and Can Gio Sea. MPs were found at all sites, with the highest average abundance of MPs being 104.17 ± 162.44 pieces/m3 in canals, followed by 2.08 ± 2.22 pieces/m3 in the sea, and 0.60 ± 0.38 pieces/m3 in the river. Fragment, fiber, and granule were three common shapes, and each shape was dominant in one sampling area. White was the most common MP color at all sites. A total of 13 polymers and co-polymers were confirmed, and polyethylene, polypropylene, and ethylene-vinyl acetate were the three dominant polymers. The total concentration of MPs-affiliated PAHs ranged from 232.71 to 6448.66, from 30.94 to 8940.99, and from 432.95 to 3267.88 ng/g in Can Gio sea, canals, and Saigon River, respectively. Petrogenic sources were suggested as a major source of PAHs associated with MPs in Can Gio Sea, whereas those found in Saigon River and canals were from both petrogenic and pyrogenic sources.

Microplastics shift macrobenthic community structures near a coastal nuclear power plant under construction in North East China

Coastal sediments are considered to be a potential sink for microplastics, which mainly derived from the land-based sources. This study investigated microplastic pollution in the sediments of 20 stations near a nuclear power plant under construction in North East China and analyzed its impacts on macrobenthic communities. The average abundance of microplastics in three stations close to the nuclear power plant was 0.33 items/g, which was approximately 10 times higher than those in the distant stations. The clustering of microplastic characteristics (sizes, shapes, and colors) showed that the three stations near the plant were in one group, and the distant stations were in another group. A total of 105 macroinvertebrate species belonging to 7 phyla were identified in all stations, and the dominant phyla were Annelida and Arthropoda. Spearman rank correlation showed that rare taxa (83 species with a contribution <1 %) were positively correlated with microplastics and As, and redundancy analysis demonstrated that the distribution patterns of macrobenthic communities were similar to those of microplastics. Moreover, co-occurrence networks showed that the rare taxa were positively correlated with microplastics. Therefore, microplastics released from the nuclear power plant under construction might shift the structure of macrobenthic communities, especially the rare taxa.

Impacts of terrestrial input on the distribution characteristics of microplastics in the East China Sea characterized by chromophoric dissolved organic matter (CDOM) analysis

Large quantities of microplastics are found in the East China Sea (ECS), however, the impacts of complicated terrestrial input on the distribution characteristics of microplastics have not been studied. Hence, we aimed to characterize the microplastic distribution in the ECS combined with the fluorescence characteristics of chromophoric dissolved organic matter (CDOM), a sensitive technique to trace terrestrial substances in seawater. The average microplastic abundance in the surface seawater of ECS was 34.73 ± 4.05 items/m3 and sites in the north ECS had a higher microplastic abundance (55.90 ± 2.47 items/m3) than those in the southern region (11.22 ± 4.01 items/m3), due to its proximity to the Yangtze River estuary and Hangzhou Bay. Polyethylene (PE, 44.2 %) was the most abundant microplastic type in the northern region, whereas polyethylene terephthalate (PET, 28.4 %) had a higher proportion in the south ECS. Besides, sites in the north ECS had a higher diversity index of microplastics, suggesting various sources of microplastic pollution. Interestingly, a stronger correlation with the diversity index was found for protein-like component C3 (R2 = 0.56) in northern regions compared to fulvic-like component C1 (R2 = 0.32) and humic-like component C2 (R2 = 0.28), suggesting the significant impact of anthropogenic discharge. Moreover, no correlation between fluorescence components and microplastic diversity index was found in the south ECS, indicating that CDOM can reflect the impact range of terrestrial input on the distribution characteristics of microplastics. This research might be useful in assessing and reducing the impact of terrestrial input on the distribution characteristics of microplastics in the ECS.

Distribution Characteristics of Microplastics and Their Migration Patterns in Xiangxi River Basin

Microplastics as a prevalent pollutant in water bodies have recently attracted widespread attention. To investigate the spatial and temporal distribution characteristics of microplastics in freshwater rivers and their migration patterns, the surface water, sediments, and subsidence zone of the Xiangxi River, a tributary of the Yangtze River, were sampled and analyzed in November 2020 and April 2021, respectively. The results showed that the average abundance of microplastics in the surface water of Xiangxi River was (6.64±1.32) n·L-1 in flat water and (5.00±1.07) n·L-1 in dry water, the average abundance of microplastics in sediments was (0.56±0.13) n·g-1 in flat water and (0.41±0.09) n·g-1 in dry water, and the average abundance of microplastics in the subsidence zone was (0.53±0.15) n·g-1 in flat water and (0.68±0.18) n·g-1in dry water. There were significant differences in the abundance distribution of microplastics in the surface water, sediments, and subsidence zone (P<0.05). In the surface water and sediments, the particle size of microplastics was mainly distributed in the range of 0.1-0.5 mm, and in the subsidence zone, it mainly ranged from 1-5 mm. The color of microplastics was mainly transparent in the surface water and subsidence zone and blue in sediments. The morphology of microplastics in the Xiangxi River basin was mainly fiber, and the materials were mainly polyethylene (PE) and polypropylene (PP). There were many factors affecting the distribution of microplastics. The analysis results showed that the abundance of microplastics in the surface water was negatively correlated with the flow rate of the water body. The abundance of microplastics in the sediment was related to the substrate type of the riverbed and negatively correlated with the substrate particle size. Combined with the microplastic abundance data of each sampling site, it was found that there was a significant migration process of microplastics in the spatial distribution of the Xiangxi River in the watershed. Along the river longitudinal direction, the longitudinal migration of microplastics in the surface water was along the river direction, and in the vertical direction, it showed the mutual migration between the water body and the subsidence zone and the water body and sediments.

Distribution and types of microplastics on the coast of Aipiri and Andai Beaches, Manokwari District, Indonesia

Abstract. Embulaba O, Kolibongso D, Tapilatu RF, Saleh F, Bawole R. 2022. Distribution and types of microplastics on the coast of Aipiri and Andai Beaches, Manokwari District, Indonesia. Indo Pac J Ocean Life 6: 10-16. Plastic waste enters the marine environment in various sizes, from micrometers to millimeters. The composition and occurrence of microplastics were investigated on the Manokwari coast (Manokwari District, Indonesia) from two different beaches in terms of intensity of exploitation and exposure to various activities such as urbanization, ports, tourism, and morphological characteristics of the coast. The average abundance of microplastics was between 0.001 to 0.041 items/gram of dry sediment. Fragments and fibers are the two types of microplastics found to dominate. On the other hand, there was no substantial difference in the abundance of microplastics found on unexposed beaches with other beaches. Our results show that coastal morphology with gentle slopes with high tide limits tends to have a 'better' potential for accumulating microplastics on the beach. However, the accumulation of microplastic types is also primarily determined by the characteristics possessed by microplastics. Therefore, it causes spatial and temporal variability in the composition of microplastics found on the coast.

Microplastic pollution at Qilianyu, the largest green sea turtle nesting grounds in the northern South China Sea.

Microplastics, new persistent pollutants, have recently attracted considerable attention. When present in beach sediments, microplastics may adversely affect the nesting and hatching of sea turtles on beaches. In this study, we investigate microplastic pollution at Qilianyu (northeastern Xisha Islands), the largest known nesting ground for green sea turtles (Chelonia mydas) in China. We found that the average abundance of microplastics in the beach surface sediments was 338.44 ± 315.69 thousand pieces·m−3 or 1,353.78 ± 853.68 pieces·m−2, with foam and fragments as the main microplastic type identified. The microplastic particles were categorised as small and were predominantly within the 0.05–1 mm size category. Most microplastic particles were white (71.31%). Polystyrene and polyethylene were found to be the most common forms of plastic present. Microplastic pollution was not only observed on the beach surface but also at the bottom of nests approximately 60 cm may be harmful to the incubation of sea turtle eggs. We suggest removing plastic litter, especially small pieces of plastic, on beaches to reduce the threat of microplastic pollution to marine life, including sea turtles. Furthermore, the foam used in aquaculture should be recovered and replaced before it becomes fragmented due to age. In addition, regional cooperation between stakeholders in the South China Sea should be strengthened to collectively promote the reduction and cleanup of marine litter.

Identification Of Microplastics Content in Sediment, Water and Digestive Channel of Milkfish (Chanos chanos) in Sidoarjo Pond

Microplastics are a form of new pollution that the Indonesian people are not aware of. The factors for the entry of microplastics into pond waters are water sources, anthropogenic activities, and pond cleanliness. The purpose of this study was to determine the abundance of microplastics, the color and shape of microplastics, and the types of microplastic polymers found in sediment, water, and the digestive tract of milkfish (Chanos chanos) in Sidoarjo ponds. The average abundance of microplastics in sediment samples obtained from semi-intensive ponds is 300 particles per 50 grams, while the sediment samples from traditional ponds are 613 particles per 50 grams. The average abundance of microplastics in the semi-intensive pond water samples was 2.1 particles per 20 liters and in traditional ponds was 2.3 particles per 20 liters. The average abundance of microplastics in the milkfish (Chanos chanos) samples from the Semi-Intensive Pond was as many as 6 particles per tail, while the Traditional Pond had 9.5 particles per tail. In this study, four colors of microplastics were found, namely blue, black, red, and transparent, while the microplastics obtained were fiber, fragment, and filament. The types of microplastic polymers encountered in this study were dominated by polyamide or nylon polymers. In sediment samples from both ponds, we found the presence of Polyamide or Nylon polymers, namely Polystyrene and Polyamide or Nylon, and in the digestive tract of milkfish (Chanos chanos), namely Polyamide or Nylon.

Spatial and temporal distributions of microplastics and their macroscopic relationship with algal blooms in Chaohu Lake, China

Microplastics are emerging pollutants with sizes less than 5 mm, and they are ubiquitous. The occurrence of algal blooms has become a major problem affecting water quality in Chaohu Lake. To understand the relationship between the microplastic distribution and algal bloom density from a macroscopic point of view in Chaohu Lake, we collected microplastic samples from water and sediments during the wet and dry seasons and collected satellite remote sensing images of the algae density in recent years. The research results showed that the spatial and temporal distributions of microplastics were uneven and varied greatly. The average abundances of microplastics in the water samples were 2133 ± 1534 n•m−3 in the dry season and 1679 ± 1577 n•m−3 in the wet season, and the average abundance of microplastics in sediments was 308 ± 231 n•kg−1. The abundance of microplastics in the estuaries was higher than those in other locations, and it was higher in the western part of the lake than in the eastern part. The microplastics in water and sediments presented different sizes, colors, shapes and compositions. The abundance, distribution and migration of microplastics were mainly affected by population density, rainfall, runoff, hydrodynamic force and wind direction. At a more macroscopic level, the distribution of microplastics was similar to that of algal blooms, TN and TP to some extent, especially in the early stage of algal bloom outbreaks, and the algal density was significantly positively correlated with the flux of microplastics into the lake. Microplastics, as carriers of algae, could promote the growth of algae blooms in the early stage, while in the later stage, microplastics and algal blooms could aggregate and coprecipitate through adsorption or adhesion and then inhibit the growth of algae.

Distribution characteristics of microplastics in surface and subsurface Antarctic seawater

Microplastics have attracted worldwide attention due to their potential threat to the marine ecosystem, with such pollutants even detected in the polar seas. Although in-depth research on microplastics has increased in recent years, studies in Antarctic waters remain relatively scarce compared with coastal waters and open oceans. In this study, microplastics in surface and subsurface Antarctic waters were investigated. The average microplastic abundance in the surface water was 0.10 ± 0.14 items/m3, with highest abundance in the Ross Sea, and the average microplastic abundance in the subsurface water was 1.66 ± 1.20 items/m3, with highest abundance in the Dumont d'Urville Sea. Polyester was the main microplastic in the surface waters (87.3%), while polypropylene (33.1%), polyester (28.7%), and polyethylene (22.8%) were the dominant microplastics in the subsurface waters. Results indicate that microplastic pollution in Antarctic waters may come from the Antarctic continent as well as southward transport from the ocean at mid- and low latitudes.

Microplastic Variations in Land-Based Sources of Coastal Water Affected by Tropical Typhoon Events in Zhanjiang Bay, China

Increasingly serious microplastic pollution in coastal areas and the ecological threats associated with plastics have attracted global attention. The frequency and intensity of typhoons have increased owing to global warming, strongly influencing the distribution and composition of microplastics in coastal ecosystems. In this study, the abundance, composition, diversity, and flux of microplastics in three estuaries and one sewage outlet in Zhanjiang Bay (ZJB) were analyzed. The average abundance of microplastics from land-based sources increased 3.6-fold from 14.19 ± 3.60 items/L before Typhoon Kompasu to 51.19 ± 28.53 items/L after the typhoon (p &lt; 0.05). In addition, the proportion of fiber and large microplastics increased after the typhoon. In all samples, microplastics 100–330 μm in size were predominant, and blue was the most abundant color. The diversity in the color and size of microplastics increased after Typhoon Kompasu. The total daily flux of microplastics at the four stations entering ZJB was 3.95 × 1011 items before the typhoon and 9.93 × 1011 items after the typhoon, showing a 2.5-fold increase. This study demonstrated the influence of Typhoon Kompasu on microplastics from land-based sources of ZJB coastal waters and provided vital data for further study on MP pollution in coastal water ecosystems and the impact of typhoons on microplastics.

A large-scale study of microplastic abundance in sediment cores from the UK continental shelf and slope

To inform risk assessments, reliable, time efficient and affordable quantification methods are required for creating a microplastic (MP) pollution baseline in the world's oceans. To facilitate this, MP abundance was investigated in sediments of three contrasting areas of the UK continental shelf: North West of Jones Bank, the Canyons in the Celtic Sea and Dogger Bank in the North Sea, utilising the Nile Red tagging method to assess its time efficiency and cost. Average MP abundance in the top 10 cm was 1050–2700 MP kg−1. MP abundance decreased with increasing sediment depth and increased with increasing water depth. The findings emphasise the extent of MP pollution and illustrate the value of Nile Red for large scale mapping at relatively low cost.

Occurrence of microplastics in a pond-river-lake connection water system: How does the aquaculture process affect microplastics in natural water bodies

Aquaculture activities have been considered to be important sources of microplastics to the water. Microplastic contamination closely related to aquaculture activities has been found in mariculture areas as well as in there nearby natural water bodies. However, for freshwater bodies with complex connectivity, it remains to be revealed how aquaculture activities affect microplastics in neighboring natural water bodies. In this study, we investigated the occurrence of microplastics of a water system consisting of aquaculture ponds, rivers, and lakes in June and December, which represented different aquaculture stages. The average microplastic abundances in June were 167 (67–367) items/m3, 129 (67–233) items/m3, and 372 (100–1167) items/m3, respectively in the lake, river, and aquaculture ponds, while in December, those were 533 (200–933) items/m3, 311 (200–600) items/m3, and 429 (200–600) items/m3, respectively. Microplastic abundance in ponds was significantly higher than in the river in June, while there was no significant spatial difference of microplastic abundance in December. Microplastics abundances in both river and lake were significantly higher in December than in June. The characteristics of morphology, size, color, and polymer type of microplastics were also different among different water bodies in June. However, the differences became smaller in December. The results of this study implied that the drainage of aquaculture ponds might increase the microplastics abundances of natural water in the water system predominated by aquaculture ponds. Further studies of the environmental fate of microplastics in ponds would be beneficial for understanding and controlling microplastics in the whole water system.

Distribution Characteristics and Source Analysis of Microplastics in Urban Freshwater Lakes: A Case Study in Songshan Lake of Dongguan, China

Current studies on microplastic pollution mainly focus on marine systems. However, few studies have investigated microplastics in an urban lake. This research intends to use an urban lake (Songshan Lake) as an example to explore the pollution characteristics of microplastics and use the principal component as well as the heat map analysis to discuss the relationships between different shapes of microplastics. According to this study, the average abundance of microplastics in the surface water and surface sediments of Songshan Lake were, respectively, 2.29 ± 0.98 items/m3 and 244 ± 121 items/kg; thin films were the major microplastics in both media; transparent this type of color has the most microplastic content. The particle size of microplastics was mainly 0.18–0.6 mm (43.3%) in surface water and 1–2 mm (48.3%) in surface sediments. The composition included five polymers: polyethylene (PE), polypropylene (PP), polypropylene–polyethylene copolymer (PP–PE copolymer), polystyrene (PS), and polyvinyl chloride (PVC), among which PE (47%) and PP (36%) were the main components. Principal component analysis (PCA) showed that there was a positive correlation among the four shapes of microplastics: films, fragments, foams, and fibers. The heat map analysis showed that the same category of shape distribution features may be similar for each sampling site.

Microplastic contamination in seafood from Dongshan Bay in southeastern China and its health risk implication for human consumption

Microplastic (MP) pollution has been a considerable concern due to its ubiquity in the environment and its potential to harm human health. Unfortunately, the exact levels of MP in various species of seafood species have not been established. It is also unclear whether or not consuming seafood contaminated with MPs directly jeopardizes human health. Here, eight popular species of seafood in Dongshan Bay, China were investigated to determine the presence of MP pollution and its implications on human health. The abundance, color, size, shape, type, surface morphology, danger of the MPs extracted from the seafood were analyzed. Results showed that the average MP abundance in the shellfish and fish was 1.88 ± 1.44 and 1.98 ± 1.98 items individual−1, respectively. The heavy presence of fibers may be attributed to the shellfish and fish's feeding behaviors as well as their habitat and environment. The sizes of MPs found were below 1.0 mm. The main types of MP found in the shellfish were PES and PET, whereas the main types found in the fish were PS and PES. Risk assessment suggested that MPs in the shellfish (risk Level V) posed a greater and more direct threat to human health if the shellfish is eaten whole. The MPs in the gastrointestinal tracts (GITs) of fish (risk Level IV) have a relatively limited effect on human health since GITs are seldom consumed by humans unless the fish is heavily processed (canned or dried). MPs-induced health risk is predicted using a technique called molecular docking. The results of this study not only establish levels of MP pollution in popular seafood species but also help understand the implications of consuming MP-contaminated seafood on human health.

Zonal Distribution Characteristics of Microplastics in the Southern Indian Ocean and the Influence of Ocean Current

As a new type of pollutant, microplastics widely exist in the marine environment and have attracted a lot of attention from the international community. In order to study the distribution of microplastics and the influence of ocean current, microplastic samples in seawater of the southern Indian Ocean were collected using a peristaltic pump equipped on-board and concentrated on site. Qualitative and quantitative analyses of microplastics were performed using a stereo-microscope and a micro-Fourier transform infrared spectroscope attenuated total reflection. The results showed that the average abundance of microplastics in seawater of the southern Indian Ocean was 2.3 ± 2.1 items/m3, which was consistent with that in other oceans. Polyethylene terephthalate (PET), polyethylene (PE), Rayon, polyamide (PA), and polyvinylidene chloride (PVDC) were the main polymers of microplastics in the southern Indian Ocean. The size range of all detected microplastics was 108.2–4703.0 µm. All microplastics had different colors, such as black, red, yellow, gray, blue, green, purple, and transparent. Fiber was the dominant shape of microplastics. The abundance distribution of microplastics fluctuated in the latitudinal direction. The abundance of microplastics from the present study area was higher in the coastal region of the South Africa continent and the Indian Ocean garbage patch, with an average abundance of 4.0 items/m3. The average abundance of microplastics was relatively high in the convergence area of the circulation, which revealed that the ocean current facilitated the agglomeration and transportation of microplastics.