Vol. 77 (1) 2025
ARTICLES
Effects of Microplastics and Metal Pollution on Bivalves from the Bulgarian Black Sea Sublittoral, with Comments on their Adaptive Capacity
Georgi I. Pramatarov1*, Elina R. Tsvetanova2, Vladimir M. Ilinkin3, Madlena N. Andreeva2, Albena V. Alexandrova2 & Nesho H. Chipev2
More info
*1Department of Biotechnology, Faculty of Biology, Sofia University “St. Kliment Ohridski”, 1164 Sofia, Bulgaria
2Laboratory of Free Radical Processes, Institute of Neurobiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
3National Society “Ecological Engineering and Environmental Protection”, Sofia, Bulgaria
Abstract
The present study aimed to assess the effects of microplastics (MPs) and metal bioaccumulation on the bivalve species Donax trunculus Linnaeus, 1758, Cerastoderma edule (Linnaeus, 1758), Mya arenaria Linnaeus, 1758 and Mytilus galloprovincialis Lamarck, 1819 from the Bulgarian Black Sea coast and their adaptive capacity to pollution. The MPs accumulation in the bivalves was observed under a stereomicroscope after 10% KOH tissue digestion. Metal elements (Cd, Cu, Cr, Ni, Pb, Zn and Fe) in the bivalve soft tissues were measured by EPA-METHOD 3052. The effects of pollutants on the bivalve species were assessed by oxidative stress (OS) biomarkers, which were measured spectrophotometrically. MPs were observed in all studied species but at a different ratio, pellets being the most numerous (94.7%). The accumulated MPs and metal elements induced OS but significantly correlated with different OS indices in the individual bivalve species. The principal component analysis suggested that the MPs accumulation probably leads to changes in bivalve cells similar to those caused by Pb and associated with protein oxidation and glutathione levels. In conclusion, the accumulated MPs and metal elements caused OS in all studied bivalves, which, in turn, activated their antioxidant system. This suggested the presence of adaptive potential of the bivalve species to the current ecological state of the marine environment in their habitats of the Bulgarian Black Sea sublittoral.
Key words
adaptive potential, bivalves, Bulgarian Black Sea, metal elements, microplastics, oxidative stress
How to Cite
Pramatarov G.I., Tsvetanova E.R., Ilinkin V.M., Andreeva M.N., Alexandrova A.V. & Chipev N.H. 2025. Effects of Microplastics and Metal Pollution on Bivalves from the Bulgarian Black Sea Sublittoral, with Comments on their Adaptive Capacity. Acta zoologica bulgarica 77 (1) 107-119.
References
- Adeleye A. T., Bahar M. M., Megharaj M., Fang C. & Rahman M. M. 2024. The unseen threat of the synergistic effects of microplastics and heavy metals in aquatic environments: a critical review. Current Pollution Reports 10: 478–497. https://doi.org/10.1007/s40726-024-00298-7
- Alexandrova A. V., Ignatova-Ivanova T. V., Bachvarova D. G., Toschkova S. G., Doichinov A. H., Ibryamova S. F. & Chipev N. H. 2022. Pilot screening and assessment of microplastic bioaccumulation in wedge clams Donax trunculus Linnaeus, 1758 (Bivalvia) from the Bulgarian Black Sea Coast. Acta Zoologica Bulgarica 74: 568–578. https://www.acta-zoologica-bulgarica.eu/2022/002641
- Alexandrova A. V., Tsvetanova E. R., Georgieva A. P., Andreeva M. N., Pramatarov G. I., Kanzova H., Petrov G. K. & Chipev N. H. 2024. Redox status as a health indicator of economically important fish from the northern shelf of the Bulgarian Black Sea. Acta Zoologica Bulgarica, Supplement 20: 15–25. https://www.acta-zoologica-bulgarica.eu/2024/Suppl_20_03
- Alimi O. S., Farner Budarz J., Hernandez L. M. & Tufenkji N. 2018. Microplastics and nanoplastics in aquatic environments: aggregation, deposition, and enhanced contaminant transport. Environmental Science & Technology 52(4): 1704–1724.
- Bat L., Şahin F., Öztekin A., Özsandıkçı U. & Özkan E. Y. 2024a. Comprehensive risk assessment of metals in surface sediments of the Southern Black Sea coastal and transition waters. Regional Studies in Marine Science 75: 103561.
- Bat L., Yardım Ö., Öztekin A. & Arıcı E. 2024b. Assessing health risks from metal contamination in Engraulis encrasicolus (Linnaeus, 1758) along the Black Sea, Journal of Food Composition and Analysis 132: 106309.
- Berov D. & Klayn S. 2020. Microplastics and floating litter pollution in Bulgarian Black Sea coastal waters. Marine Pollution Bulletin 156: 111225.
- Bobchev N., Berov D., Klayn S. & Karamfilov V. 2024. High microplastic pollution in marine sediments associated with urbanised areas along the SW Bulgarian Black Sea coast. Marine Pollution Bulletin 209: 117150. https://doi.org/10.1016/j.marpolbul.2024.117150
- Brahmstedt E.S., Crespo C.N.A. & Holsen T.M. 2021. Mercury distribution in an Upper St. Lawrence River wetland dominated by cattail (Typha angustifolia). Wetlands 41: 119. https://doi.org/10.1007/s13157-021-01511-9
- Chen Q., Zhao H., Liu Y., Jin L. & Peng R. 2023. Factors affecting the adsorption of heavy metals by microplastics and their toxic effects on fish. Toxics 11: 490. https://doi.org/10.3390/toxics11060490
- Costantini D. 2014. Oxidative stress and hormesis in evolutionary ecology and physiology. A marriage between mechanistic and evolutionary approaches, 362 p.
- Damir N., Coatu V., Danilov D., Lazăr L. & Oros A. 2024. From waters to fish: a multi-faceted analysis of contaminants’ pollution sources, distribution patterns, and ecological and human health consequences. Fishes 9(7): 274. https://doi.org/10.3390/fishes9070274
- Das A. 2023. The emerging role of microplastics in systemic toxicity: Involvement of reactive oxygen species (ROS). Science of the Total Environment 895: 165076.
- Ellman G. L., Courtney K. D., Andres Jr V. & Featherstone R. M. 1961. A new and rapid colorimetric determination of acetylcholinesterase activity. Biochemical Pharmacology 7(2): 88–95.
- Emenike E. C., Iwuozor K. O. & Anidiobi S. U. 2022. Heavy metal pollution in aquaculture: sources, impacts and mitigation techniques. Biological Trace Elements Research 200: 4476–4492.
- Ferreira O., Barboza L. G. A., Rudnitskaya A., Moreirinha C., Vieira L. R., Botelhon M. J., Vale C., Fernandes J. O., Cunha S. & Guilhermino L. 2023. Microplastics in marine mussels, biological effects and human risk of intake: A case study in a multi-stressor environment. Marine Pollution Bulletin 197: 115704.
- Forman H.J., Zhang H. 2021. Targeting oxidative stress in disease: promise and limitations of antioxidant therapy. National Review of Drug Discovery 20: 689–709. DOI: 10.1038/s41573-021-00233-1.
- Franco A. A., Iglesias-Arroyo D., Egea-Corbacho Á., Martín-García A. P., Quiroga J. M., & Coello M. D. 2023. Influence of tourism on microplastic contamination at wastewater treatment plants in the coastal municipality of Chiclana de la Frontera. Science of the Total Environment 900: 165573.
- Ganchev T., Markova V., Valcheva-Georgieva I. & Dobrev I. 2023. Pollution of Varna Lake and possibilities of using the pollutants as resources. E3S Web of Conferences 404: 03002, https://doi.org/10.1051/e3sconf/202340403002
- Gao F., Li J., Sun C., Zhang L., Jiang F., Cao W. & Zheng L. 2019. Study on the capability and characteristics of heavy metals enriched on microplastics in marine environment. Marine Pollution Bulletin 144: 61–67. https://doi.org/10.1016/j.marpolbul.2019.04.039
- Georgieva S. K., Peteva Z. V. & Stancheva M. D. 2023. Evaluation of abundance of microplastics in the Bulgarian coastal waters. BioRisk 20: 59–69.
- Hines E., Jaubet M. L., Cuello G. V., Elías R. & Garaffo G. V. 2023. Macro-, meso-and microplastic abundance in sandy beaches and factors influencing their distribution in an SW Atlantic resort. Marine Environmental Research 190: 106104.
- Ibryamova S. F., Toschkova S., Bachvarova D. C., Stanachkova E., Ivanov R. I., Natchev N. D. & Ignatova-Ivanova T. V. 2023. Study of the dynamics of the microbial communities in the wedge clam Donax trunculus (Linnaeus, 1758) from the Bulgarian aquatory of the Black Sea. BioRisk 21: 29–40.
- Ighodaro O.M. & Akinloye O.A. 2018. First line defence antioxidants superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX): Their fundamental role in the entire antioxidant defence grid. Alexandria Journal of Medicine 54:4: 287–293.
- Ito Y., Niiya Y., Kurita H., Shima S. & Sarai S. 1985. Serum lipid peroxide level and blood superoxide dismutase activity in workers with occupational exposure to lead. International archives of occupational and environmental health 56(2), 119–127. https://doi.org/10.1007/BF00379383
- Jamil Emon F., Rohani M. F. Sumaiya N., Tuj Jannat M. F., Akter Y., Shahjahan M., Goh K. W. 2023. Bioaccumulation and bioremediation of heavy metals in fishes – a review. Toxics 11(6): 510.
- Jaubet M. L., Hines E., Elias R. & Garaffo G. V. 2021. Factors driving the abundance and distribution of microplastics on sandy beaches in a Southwest Atlantic seaside resort. Marine Environmental Research 171: 105472.
- Jomova K., Alomar S. Y., Alwasel S. H., Nepovimova E., Kuca K. & Valko M. 2024. Several lines of antioxidant defense against oxidative stress: antioxidant enzymes, nanomaterials with multiple enzyme-mimicking activities, and low-molecular-weight antioxidants. Archives of Toxicology 98(5): 1323–1367. https://doi.org/10.1007/s00204-024-03696-4
- Kadac-Czapska K., Ośko J., Knez E. & Grembecka M. 2024. Microplastics and oxidative stress-current problems and prospects. Antioxidants (Basel) 13(5): 579. DOI: 10.3390/antiox13050579.
- Kasperczyk S., Kasperczyk A., Ostałwska A., Dziwisz M. & Birkner E. 2004. Activity of glutathione peroxidase, glutathione reductase, and lipid peroxidation in erythrocytes in workers exposed to lead. Biological Trace Element Research 102: 61–72.
- Khalid N., Aqeel M., Noman A., Khan S. M. & Akhter N. 2021. Interactions and effects of microplastics with heavy metals in aquatic and terrestrial environments. Environmental Pollution 290: 118104. https://doi.org/10.1016/j.envpol.2021.118104
- Kournouto G. G., Giannopoulou P. C., Sazakli E., Leotsinidis M., Kalpaxis D. L. & Dinos G. P. 2020. Oxidative damage of mussels living in seawater enriched with trace metals, from the viewpoint of proteins expression and modification. Toxics 8 (4): 89. DOI: 10.3390/toxics8040089.
- Kumar M., Singh S., Jain A., Yadav S., Dubey A. & Trivedi S. P. 2024. A review on heavy metal-induced toxicity in fishes: Bioaccumulation, antioxidant defence system, histopathological manifestations, and transcriptional profiling of genes. Journal of Trace Elements in Medicine and Biology 83: 127377. https://doi.org/10.1016/j.jtemb.2023.127377
- Liu S., Shi J., Wang J., Dai Y., Li, H., Li, J., … & Zhang, P. 2021. Interactions between microplastics and heavy metals in aquatic environments: a review. Frontiers in Microbiology 12: 652520.
- Lushchak V. I. 2011. Environmentally induced oxidative stress in aquatic animals. Aquatic Toxicology 101(1): 13–30.
- Lusher A. L. & Hernandez-Milian G. 2018. Microplastic extraction from marine vertebrate digestive tracts, regurgitates and scats: A protocol for researchers from all experience levels. Bio-protocol 8(22): e3087–e3087.
- Manev I., Kirov V. & Neshovska H. 2020. Heavy metals accumulation in Black Sea ecosystems: seawater, sediment, algae, benthic organisms. Tradition And Modernity In Veterinary Medicine 5(2): 88–99.
- Manev I., Neshovska H. & Kirov V. 2021. Heavy metal levels in anchovy (Engraulis encrasicolus L.) from Bulgarian Black Sea coast. Zhivotnovadni Nauki 56 (6): 68–73.
- Mejdoub Z., Fahde A., Loutfi M. & Kabine M. 2017. Oxidative stress responses of the mussel Mytilus galloprovincialis exposed to emissary’s pollution in coastal areas of Casablanca. Ocean & Coastal Management 136: 95–103.
- Mihova S., Alexandrova A., Doncheva V., Stefanova K., Ivanova P. & Chipev N. 2024. Microplastic uptake by Mya arenaria Linnaeus, 1758, Mytilus galloprovincialis Lamarck, 1819 and Cerastoderma glaucum (Bruguière, 1789) (Bivalvia) from Varna Lake, Bulgaria. Acta Zoologica Bulgarica 76 (3): 367–374.
- Miranda T., Vieira L.R. & Guilhermino L. 2019. Neurotoxicity, behaviour, and lethal effects of Cadmium, microplastics, and their mixtures on Pomatoschistus microps juveniles from two wild populations exposed under laboratory conditions – Implications to environmental and human risk assessment. International Journal of Environmental Research and Public Health 16: 2857.
- Mitryasova O., Koszelnik P., Gruca-Rokosz R., Smirnov V., Smirnova S., Bezsonov Y., … & Ziembowicz S. 2020. Features of heavy metals accumulation in bottom sediments of the Southern Bug hydroecosystem. Journal of Ecological Engineering 21 (3): 51–60.
- Moncheva S., Stefanova K., Krastev A., Apostolov A., Bat L., Sezgin M., … & Timofte F. 2016. Marine litter quantification in the Black Sea: a pilot assessment. Turkish Journal of Fisheries and Aquatic Sciences 16 (1): 213–218.
- Morais T., Moleiro P., Leite C., Coppola F., Pinto J., Henriques B., Soares A. M.V. M., Pereira E. & Freitas R. 2023. Ecotoxicological impacts of metals in single and co-exposure on mussels: Comparison of observable and predicted results. Science of the Total Environment 881: 163165.
- Oliveira M., Ribeiro A., Hylland K. & Guilhermino L. 2013. Single and combined effects of microplastics and pyrene on juveniles (Pomatoschistus microps): changes in behavour and biochemical responses. Aquatic Toxicology 157: 16–24.
- Oros A., Pantea E.-D. & Ristea E. 2024. Heavy metal concentrations in wild mussels Mytilus galloprovincialis (Lamarck, 1819) during 2001–2023 and potential risks for consumers: a study on the Romanian Black Sea coast. Sci 6: 45. https://doi.org/10.3390/ sci6030045
- Patil A. J., Bhagwat V. R., Patil J. A., Dongre N. N., Ambekar J. G., Jailkhani R. & Das K. K. 2006. Effect of lead (Pb) exposure on the activity of superoxide dismutase and catalase in battery manufacturing workers (BMW) of Western Maharashtra (India) with reference to heme biosynthesis. International Journal of Environmental Research and Public Health 3(4): 329–337. https://doi.org/10.3390/ijerph2006030041
- Patra R. C., Rautray A. K. & Swarup D. 2011. Oxidative stress in lead and cadmium toxicity and its amelioration. Veterinary Medicine International: 457327. DOI: 10.4061/2011/457327.
- Peycheva K., Panayotova V., Stancheva R., Makedonski L., Merdzhanova A., Cicero N., Parrino V., Fazio F. 2021. Trace elements and omega-3 fatty acids of wild and farmed mussels (Mytilus galloprovincialis) consumed in Bulgaria: human health risks. International Journal of Environmental Research and Public Health 18(19): 10023. DOI: 10.3390/ijerph181910023.
- Peycheva K., Panayotova V., Stancheva R., Makedonski L., Merdzhanova A., Cicero N., Camilleri G. & Fazio F. 2022. Trace elements and omega-3 fatty acids of Black Sea (Bulgaria) bivalve species Mytilus galloprovincialis, Chamelea gallina and Donax trunculus. Human health risk. Natural Product Research 36(11): 2735–2742. https://doi.org/10.1080/14786419.2021.1921770
- Pojar I. & Stock F. 2019. Microplastics in surface waters from the northwestern Black Sea: an abundance and composition approach. Geophysical Research Abstracts, Vol. 21.
- Qi K., Lu N., Zhang S., Wang W., Wang Z. & Guan J. 2021. Uptake of Pb (II) onto microplastic-associated biofilms in freshwater: adsorption and combined toxicity in comparison to natural solid substrates. Journal of Hazardous Materials 411: 125115.10.1016.
- Richard H., Carpenter E. J., Komada T., Palmer P. T. & Rochman C. M. 2019. Biofilm facilitates metal accumulation onto microplastics in estuarine waters. Science in the Total Environment 683: 600–608. DOI: 10.1016/j.scitotenv.2019.04.331
- Santhosh K., Kamala K., Ramasamy P., Musthafa M. S., Almujri, S. S., Asdaq S. M. B., & Sivaperumal P. 2024. Unveiling the silent threat: heavy metal toxicity devastating impact on aquatic organisms and DNA damage. Marine Pollution Bulletin 200: 116139. doi.org/10.1016/j.marpolbul.2024.116139
- Sharma S.K., Goloubinoff P. & Christen P. 2008. Heavy metal ions are potent inhibitors of protein folding. Biochemical and Biophysical Research Communications 372: 341–345.
- Simeonova A. & Chuturkova R. 2019. Marine litter accumulation along the Bulgarian Black Sea coast: categories and predominance. Waste Management 84: 182–193.
- Stadtman E. R. 1993. Oxidation of free amino acids and amino acid residues in proteins by radiolysis and by metal-catalyzed reactions. Annual Review of Biochemistry 62: 797–821. DOI: 10.1146/annurev.bi.62.070193.004053.
- Stadtman E. R. & Levine R. L. 2003. Free radical-mediated oxidation of free amino acids and amino acid residues in proteins. Amino Acids 25: 207–218. DOI: 10.1007/s00726-003-0011-2
- Tamás M. J., Sharma S. K., Ibstedt S., Jacobson T. & Christen P. 2014. Heavy metals and metalloids as a cause for protein misfolding and aggregation. Biomolecules 4(1): 252–267. https://doi.org/10.3390/biom4010252
- Vedolin M. C., Teophilo C. Y. S., Turra A. & Figueira R. C. L. 2018. Spatial variability in the concentrations of metals in beached microplastics. Marine Pollution Bulletin 129(2): 487–493. https://doi.org/10.1016/j.marpolbul.2017.10.019
- Wang T., Wang L., Chen Q., Kalogerakis N., Ji R. & Ma Y. 2020. Interactions between microplastics and organic pollutants: Effects on toxicity, bioaccumulation, degradation, and transport. Science of the Total Environment 748: 142427.
- Welch K. D., Davis T. Z., Van Eden M. E. & Aust S. D. 2002. Deleterious iron-mediated oxidation of biomolecules. Free Radical Biology and Medicine 32 (7): 577–583.
- Windom M. L., Tenore K. T. & Rece D. L. 1982. Metal accumulation of the polychaete Capitella capitata: influences of metal content and nutritional quality of detritus. Canadian Journal of Fisheries and Aquatic Science 39: 191–196.
- Wu X., Zhong C., Wang T., Zou X., Zang Z., Li Q. & Chen H. 2021. Occurrence and distribution of microplastics on recreational beaches of Haichow Bay, China. Environmental Science and Pollution Research 28: 6132–6145.
- Xiang Y. J., Jiang L., Zhou Y. Y., Luo Z. R., Zhi D., Yang J., Lam S. S. 2022. Microplastics and environmental pollutants: key interaction and toxicology in aquatic and soil environments. Journal of Hazardous Materials 422: 126843.
- Yan F., Yang W., Li X., Lin T., Lun Y., Lin F., Lv S., Yan G., Liu J. & Shen J. 2008. A trifunctional enzyme with glutathione s-transferase, glutathione peroxidase and superoxide dismutase activity. Biochimica et Biophysica Acta 1780: 869–872. DOI: 10.1016/j.bbagen.2008.03.003
- Yiin S. J. & Lin T. H. 1995. Lead-catalyzed peroxidation of essential unsaturated fatty acid. Biological Trace Element Research 50 (2): 167–172.
- Zhang R., Wang M., Chen X., Yang C. & Wu L. 2020. Combined toxicity of microplastics and Cadmium on the zebrafish embryos (Danio rerio). Science in the Total Environment 743: 140638.
- Zolotova N., Kosyreva A., Dzhalilova D., Fokichev N. & Makarova O. 2022. Harmful effects of the microplastic pollution on animal health: a literature review. Peer J 10: e13503. DOI: 10.7717/peerj.13503.
- Zou J., Liu X., Zhang D. & Yuan X. 2020. Adsorption of three bivalent metals by four chemical distinct microplastics. Chemosphere 248: 126064. https://doi.org/10.1016/j.chemosphere.2020.126064


