Characteristics and temporal trends of microplastics in the coastal area in the Southern Black Sea over the past decade

Inter-annual variation in the microplastics abundance in feces of the Baird's tapir (Tapirus bairdii) from the Selva Maya, México

Microplastics (MPs) are found in a wide range of ecosystems, from the Arctic to the deep ocean. However, there is no data on their presence in terrestrial mammals that inhabit the Selva Maya. The aim of this study is to detect the presence of MPs in the feces of the Baird's tapir (Tapirus bairdii) from the region of Calakmul, located in the Yucatan Peninsula, Mexico. We analyzed 129 fecal samples collected during 2017 and 2018, obtaining 57 and 72 samples during the rainy and dry seasons respectively. Sixty-eight percent of the samples contained 743 MPs with a mean of 19.3 ± 28.1 MPs/kg of dry weight (DW) feces in both years. An inter-annual variation in the average abundance of microplastic was observed during the two-year period (2017-2018), with a 72 % increase in these plastic particles in feces. Fourteen polymers were identified, with ethylene vinyl acetate (EVA), polypropylene (PP) and polyester (PES) being the most abundant during both years. Although the effects of MPs on the health of tapirs are not known, their presence is cause for concern. There is an urgent need for the implementation of appropriate plastic waste management programs in communities of the Selva Maya to diminish the consumption of MPs in species including humans where they pose a significant risk to health. ENVIRONMENTAL IMPLICATIONS: The use of plastics worldwide is increasing every day, so the presence of microplastics is and will continue to be a major environmental problem. It is known that contaminants can adhere to plastics, making them hazardous materials. Microplastics can contaminate remote areas such as Biosphere Reserves. Terrestrial species such as the tapir can ingest microplastics, putting their health at risk. Knowing the dispersion of microplastics is very important in order to manage them properly, taking into account their emission sources and type of polymer.

Monitoring of microplastic pollution in sediments along the Çoruh River Basin, NE Türkiye

Microplastic (MP) pollution has become a research issue on the world agenda. Monitoring studies are essential for MP content in aquatic environments since it is the final accumulation point. The present study focused on MP characterizations in sediment samples taken from 20 different stations on the Çoruh River, the major river in the North East of Türkiye. Accordingly, the potential anthropogenic pollution from settlements near the four stations (2, 15, 18, and 20) exceeding 400 MP kg-1 was estimated. On the other hand, stations (1, 3, 9, 11, and 13) far from settlements with quite low MP abundance were also observed. The polymer structures of the detected MPs are generally PE and PET, and their shapes are mostly fiber. This situation raises suspicion that MPs originate from primary use waste such as water bottles and packaging materials. In general, the fiber MPs are smaller than the fragments because of the river's high water flow rate and the low strength of the fiber MPs. In light of these results, the current monitoring data in the region will create awareness and guidance regarding MP pollution in settlements.

A characterization and an exposure risk assessment of microplastics in settled house floor dust in Istanbul, Turkey

The presence of microplastics in the indoor environment presents growing environmental and human health risks because of their physicochemical and toxic characteristics. Therefore, we aimed to isolate, identify, and characterize plastic debris in settled house floor dusts. This study is a rare study which assess the risks of plastic debris in settled house dust through multiple approaches including the estimated daily intake, pollution loading index, and polymer hazard index. The results indicated that polyethylene and polypropylene were the predominate polymer type of plastic debris in settled house dust with various shapes and colors. The risk assessment results also indicated the serious impact of microplastics in terms of extremely dangerous contamination as well as the fact that they present a polymer hazard. Results indicated that humans have a higher risk of exposure to microplastics via ingestion rather than inhalation. In addition, infants had a higher risk of potential intake compared to other age groups.

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.

Microplastic emission trends in Turkish primary and secondary municipal wastewater treatment plant effluents discharged into the Sea of Marmara and Black Sea

Wastewater Treatment Plants (WWTPs) are recognized as one of the primary sources of microplastics, a class of contaminants that has lately gained attention. The quantity of MP that WWTPs release into the environment depends on several factors, including the treatment type, season, and population serviced. MP abundance and characterization were explored in 15 WWTP effluent waters, 9 discharged to the Black Sea from Türkiye and 6 to the Marmara Sea, with varying population densities and treatment methods. The mean MP abundance in primary treatment WWTPs (76.25 ± 49.20 MP L-1) was found to be substantially greater than that in secondary treatment WWTPs (20.57 ± 21.56 MP L-1) (p<0.05). MPs in WWTP effluent waters showed significant seasonal and spatial differences (Two Way ANOVA, Tukey, p<0.05). However, no positive correlation was detected between the population serviced and MP abundance in effluent waters. While the fiber was the dominant shape (49.5%) among MPs in effluent waters, ≈80% of the length was <1000 μm. MPs are classified into polymer types as follows: polyethylene terephthalate (34.9%) > polypropylene (32.4%) > polyethylene (19.9%) > polyamide (11%) > polystyrene (1.2%) > polyvinyl chloride (0.6%). With effluent waters from the WWTPs tested, we calculated that 1.24x1010 daily MPs are discharged into the Black Sea while 4.95x1010 MPs are into the Marmara Sea, for a combined annual discharge of 2.26x1013 MPs highlighting that WWTPs are key contributors of MP in Turkish coastal waters.

River export of macro- and microplastics to seas by sources worldwide

Seas are polluted with macro- (>5 mm) and microplastics (<5 mm). However, few studies account for both types when modeling water quality, thus limiting our understanding of the origin (e.g., basins) and sources of plastics. In this work, we model riverine macro- and microplastic exports to seas to identify their main sources in over ten thousand basins. We estimate that rivers export approximately 0.5 million tons of plastics per year worldwide. Microplastics are dominant in almost 40% of the basins in Europe, North America and Oceania, because of sewage effluents. Approximately 80% of the global population live in river basins where macroplastics are dominant because of mismanaged solid waste. These basins include many African and Asian rivers. In 10% of the basins, macro- and microplastics in seas (as mass) are equally important because of high sewage effluents and mismanaged solid waste production. Our results could be useful to prioritize reduction policies for plastics.

From source to sink: A comparative study of streamside and beach litter in the Black Sea

The increasing amount of marine litter pollution and its impact on the marine environment raises global concern. This study aims to reveal the effect of streams on marine litter density and composition. A total of ten stations on the southeastern Black Sea and six stations on the Manahoz stream were seasonally surveyed. The litter density ranged between 0.838 ± 0.33 and 4.01 ± 0.55 items/m² in the beach stations, and 0.93 ± 0.27 2.40 ± 2.18 items/m² in the streamside stations. No significant difference was determined among the seasons for both beach and streamside (Kruskal-Wallis test, p > 0.05). On the other hand, the litter density was also similar in beach and streamside stations in the same season. The litter composition consisted of > 75% plastic. Principal component analysis and PERMANOVA determined no significant difference in litter composition among beach and streamside stations. The litter items mostly consisted of single-use items. Among them, plastic beverage containers were the most abundant litter subcategory during the study (ranging between 18.79% and 34.50%). The subcategory composition exhibited a significant difference among beach and streamside stations (ANOSIM, p < 0.05), which was mainly explained by plastic pieces, beverage containers, and foams according to SIMPER analysis. Personal protection equipment that was not reported before the COVID-19 pandemic emerged. The results of our study can be used for marine litter modeling studies and legislation for restriction or ban of most abundant single-use litter items.

Protracted dynamicity of microplastics in the coastal sediment of the Southeast Black Sea

This study provided the first evaluation of microplastic abundance, features, risk assessment, and decade-changing status in sediment along the southeastern Black Sea coast. Sediment samples were collected from thirteen stations in the Southeast Black Sea in 2012 and 2022. >70 % of the detected microplastics had a length of up to 2.5 mm and consisted of fragments and fibers in shape. The average microplastic abundance in the sediment samples was 108 MP/kg. The composition in the sediment (particles/kg) was dominated by polyethylene (PE) (44.9 %), polyethylene terephthalate (PET) (27.2 %), and polypropylene PP (15.2 %). Remarkable results for contamination factors, polymeric risk assessment and contamination risk indices. The sharp rise in MPS highlighted the heavily populated stations and stream discharge locations. The data shed light on anthropogenic and basal microplastic pollution in the Southeast Black Sea, assisting in developing effective policies for preserving and managing the Black Sea environment.

Microplastic prevalence in anatolian water frogs (Pelophylax spp.)

Frogs are on the verge of extinction due to various biotic and abiotic stressors. Rivers, lakes, ponds, wetlands, and ditches that make up their habitats are exposed to different anthropogenic pollutants. Today, plastics stand out among these pollutants due to their widespread use; however, the information on microplastic (MP) accumulation in frogs is insufficient. In the present study, adult frog samples were collected from 19 different stations in Türkiye, including marsh frogs (Pelophylax ridibundus) from 18 stations and levantine frogs (Pelophylax bedriagae) from 1 station. MP was found in 147 (82.4%) of the 176 frogs that were analyzed. MP abundance in frogs varied between 0.20 and 18.93 MP individual^-1. The characterization of MPs was determined predominantly as follows; PET (70.1%) in polymer type, fiber (92.2%) in shape, navy blue/blue (76.1%) in color, and >90% were smaller than 300 μm. No significant relationship with frog's weight (correlation coefficient = 0.01, P = 0.812) or length (correlation coefficient = 0.06, P = 0.473) and MP abundance was detected. The outcomes of this survey might be a baseline to assess the ecological risks posed by MPs and to guide future experimental research.

The broad-scale microplastic distribution in surface water and sediments along Northeastern Mediterranean shoreline

Plastics manufactured to fulfil the unique demands of civilization accumulate in the sea due to their durability. Microplastics (MP) pose a greater threat than macroplastics as they can easily enter the aquatic environment and be hard to detect. MPs potentially impact several components of the marine life and food chain. This study determined MP distribution and characterization by collecting sediment from 47 different stations and surface seawater (SSW) from 29 stations in 2019 along the Turkish coast of the Eastern Mediterranean Sea. Potential MP particles were stained with Nile-Red and verified using ATR-FTIR. While MP abundance in the sediment ranged between 118 ± 97 and 1688 ± 746 MPs kg^-1, it varied between 0.18 ± 0.10 MPs m^-3 and 2.21 ± 1.75 MPs m^-3 in SSW. The MP abundance showed significant spatial variation (p < 0.05). The polymer type in the samples was determined by ATR-FTIR. In both water and sediments, polyethylene was the most common MP type (>59 %), while fragment was the most common MP form (>57.6 %), and >65 % of overall MPs were <1500 μm. The spatial pattern of MPs in the sediments and SSW was affected by the population, the magnitude of the tourism sector, the rim current, and circulation. The monitoring data presented here can provide a remarkable projection of the current trend and form a basis for future MP pollution prevention.

Solid waste composition and COVID-19-induced changes in an inland water ecosystem in Turkey

The composition and abundance of solid waste and the effect of COVID-19 measures were studied in an inland water ecosystem in Turkey. Solid waste items were collected annually for 5 years from 2017 to 2021 from seven stations located in Borçka Dam Lake (B1-B4) and Murgul Stream (M1-M3) in the Artvin Province. The highest densities by number and weight were recorded at M3 in 2020 (5.72 items/m²) and M1 in 2020 (0.39 kg/m²), respectively. However, no significant difference in density was recorded (p < 0.05) between the years. Plastic was the most abundant waste material by number of items in all the stations with a percentage contribution varying between 25.47 and 88.89%. There was a considerable increase in medical items during the COVID-19 pandemic in 2020-2021. Nonmetric multidimensional scaling (NMDS) and ANOSIM results revealed visually and statistically significant differences in solid waste composition between the years and stations. The dissimilarity between the years was driven by plastic and medical waste. The main sources of solid waste were river transportation (22.93%), improper disposal (20.74%), aquaculture activities (16.42%), and recreational and tourism activities (14.72%). The results of our study can be a baseline for transportation models, local administrations, and non-governmental organizations. Besides, the current waste management measures in Turkey are not effective in preventing waste accumulation in inland aquatic systems such as the Borçka Dam Lake and Murgul Stream. Furthermore, these findings indicate that the COVID-19 pandemic influenced solid waste composition and increased its abundance in the study area.

Solid waste composition and COVID-19-induced changes in an inland water ecosystem in Turkey

The composition and abundance of solid waste and the effect of COVID-19 measures were studied in an inland water ecosystem in Turkey. Solid waste items were collected annually for 5 years from 2017 to 2021 from seven stations located in Borçka Dam Lake (B1-B4) and Murgul Stream (M1-M3) in the Artvin Province. The highest densities by number and weight were recorded at M3 in 2020 (5.72 items/m²) and M1 in 2020 (0.39 kg/m²), respectively. However, no significant difference in density was recorded (p < 0.05) between the years. Plastic was the most abundant waste material by number of items in all the stations with a percentage contribution varying between 25.47 and 88.89%. There was a considerable increase in medical items during the COVID-19 pandemic in 2020-2021. Nonmetric multidimensional scaling (NMDS) and ANOSIM results revealed visually and statistically significant differences in solid waste composition between the years and stations. The dissimilarity between the years was driven by plastic and medical waste. The main sources of solid waste were river transportation (22.93%), improper disposal (20.74%), aquaculture activities (16.42%), and recreational and tourism activities (14.72%). The results of our study can be a baseline for transportation models, local administrations, and non-governmental organizations. Besides, the current waste management measures in Turkey are not effective in preventing waste accumulation in inland aquatic systems such as the Borçka Dam Lake and Murgul Stream. Furthermore, these findings indicate that the COVID-19 pandemic influenced solid waste composition and increased its abundance in the study area.

Future microplastics in the Black Sea: River exports and reduction options for zero pollution

The Black Sea receives increasing amounts of microplastics from rivers. In this study, we explore options to reduce future river export of microplastics to the Black Sea. We develop five scenarios with different reduction options and implement them to a Model to Assess River Inputs of pollutaNts to seA (MARINA-Global) for 107 sub-basins. Today, European rivers draining into the Black Sea export over half of the total microplastics. In 2050, Asian rivers draining into the sea will be responsible for 34-46% of microplastic pollution. Implemented advanced treatment will reduce point-source pollution. Reduced consumption or more collection of plastics will reduce 40% of microplastics in the sea by 2050. In the optimistic future, sea pollution is 84% lower than today when the abovementioned reduction options are combined. Reduction options affect the share of pollution sources. Our insights could support environmental policies for a zero pollution future of the Black 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.

The microplastic pattern of wild-caught Mediterranean mussels from the Marmara Sea

The Sea of Marmara suffers from pollutants that come from municipal/industrial discharges and the Black Sea. Microplastic (MP)s, a rising environmental concern with consequences for seafood safety, are one of these contaminants. Thus, the abundance and feature of MPs in wild populations of the Mediterranean mussel (Mytilus galloprovincialis) from 20 sites along the sea of Marmara coastlines were analyzed herein. In total, 812 MPs were detected in 412 mussels. The MPs ranged from 0.30 to 7.53 MP individual^-1 and 0.11 to 4.58 MP g^-1 fresh weight. The most common shape of the MPs detected was fiber (81.16%), the majority of which were smaller than 1 mm. Polymer types were verified by FTIR, and 14 different polymers have been identified; the dominant was polyethylene terephthalate (PET, 66.38%). When one is served by a mussel meal weekly, the risk statistics project that the exposure will be 252 MPs per portion. Yet, the risk associated with the MP-contaminated mussel consumption is insignificant according to hypothetical calculations using a chemical additive (bisphenol A).

Spatial pattern and characteristics of the benthic marine litter in the southern Black Sea shelf

The abundance and characteristics of benthic marine litter in the southern Black Sea shelf were demonstrated. During the surveys, 671 litter items weighing 83.93 kg were collected from the stations. The average density by number and weight were 460.70 ± 99.71 n/km² and 80.68 ± 48.06 kg/km². The litter density was significantly higher at 10-20 m (646.09 ± 165.63 n/km²) compared to 20-30 m (165.53 ± 81.02 n/km²) and >30 m (413.87 ± 146.59 n/km²) depth classes. Plastic (69.03%) was the most abundant material by number, followed by textile (20.94%) and metal (5.68%). The litter composition differed between the no-trawl zone and trawl ground. Our results indicate that more detailed research is needed to understand the interaction of various factors influencing transportation and accumulation of marine litter in the Black Sea.

Hallmarking microplastics of sediments and Chamelea gallina inhabiting Southwestern Black Sea: A hypothetical look at consumption risks

The consumer preference of bivalves originating from fishery or aquaculture has gained momentum in response to higher nutrition, quality, and market availability. However, potential toxicity caused by plastics, the pollution icons of the current era, could raise concerns for the sources of essential nutrients provided by bivalves. Thus, we investigated the abundance, spatial distribution, polymer composition, size, and the shapes of the microplastics (MPs) in the sediment and Chamelea gallina from 15 sites at gradual depths (10 and 30 m) along the Southwestern Black Sea coast. The abundance of the MPs ranged from 28 to 684 MP kg^-1 in the sediments and the amount of 0.22-2.17 MP individual^-1 (or 0.20-2.16 MP g^-1 fresh weight soft tissue) in C. gallina. Seven types of polymers were detected by FTIR, and the most abundant type was polyethylene terephthalate (34.2-35.1%), polyethylene (28-31.1%), and polypropylene (18.9-21%). MP sizes were ranged from 73 to 4987 μm. 47% and 65% of the MPs in the sediments and C. gallina, respectively, were <1000 μm in size. The most dominant shape of the MPs was found as fibers (56.5% for sediments and 68.9% for C. gallina). The risk data predicted that people are exposed to 304 MPs when consuming a single portion of C. gallina weekly. Hypothetical calculations performed with a chemical additive simulation (bisphenol A) showed that the risk associated with the MP-contaminated C. gallina model is negligible, and the consumption is rather beneficial due to already known positive aspects.

Microplastic contamination and characteristics spatially vary in the southern Black Sea beach sediment and sea surface water

In this study, the abundance, and characteristics of the microplastics on the southern coast of the Black Sea were assessed. More than 70% of the detected microplastics were smaller than 2.5 mm and mostly consisted of fibers and fragments. The average microplastic abundance in the beach sediment and seawater were 64.06 ± 8.95 particles/kg and 18.68 ± 3.01 particles/m³, respectively. The western coast of the study area (Marmara region) was the most polluted area, and a spatially significant difference was determined in terms of abundance. The composition in the beach sediment (particles/kg) was dominated by styrene acrylonitrile copolymer (SAC) (40.53%), polyethylene terephthalate (PET) (38.75%), and polyethylene (PE) (6.91%), whereas the seawater (particles/m³) was dominated by PET (57.26%), PE (13.52%), and polypropylene PP (11.24%). The results of our study can be a baseline for environmental modeling studies and experimental studies on the marine organisms inhabiting the Black Sea.