Microplastic contamination in Mytilus galloprovincialis from the Black Sea, Bulgaria

Microplastic (MPs) pollution has become an increasing environmental concern in marine ecosystems due to its persistence and potential effects on aquatic organisms and human health. Mytilus galloprovincialis is a filter-feeding bivalve widely used as a bioindicator of marine contamination because of its capacity to accumulate pollutants from the surrounding environment. The Black Sea is a semi-enclosed basin particularly vulnerable to anthropogenic pollution, including plastic debris originating from coastal, industrial, and riverine sources. This study investigated MP contamination in Mytilus galloprovincialis collected from an aquaculture farm in the southern Bulgarian sector of the Black Sea. Mussel samples were analyzed to determine the abundance, polymer composition, and morphological characteristics of of MPs using Laser Direct Infrared (LDIR) spectroscopy. MP particles were identified and classified according to shape and polymer type, providing detailed information on contamination patterns in commercially cultivated mussels. The analysis revealed the presence of diverse MP, with fibers being the predominant forms. Detected polymers included commonly used synthetic materials, such as polyethylene and polypropylene, but also rubber, etc. indicating multiple anthropogenic sources of pollution. The occurrence of MPs in farmed mussels highlights the widespread nature of plastic contamination in the Black Sea marine environment and raises concerns regarding the transfer of MPs through seafood consumption. These findings contribute to the understanding of MP pollution in aquaculture products from the Bulgarian Black Sea and emphasize the importance of continued monitoring and mitigation strategies to reduce marine plastic contamination.