Tracing Marine Macro- and Microplastic Pollution from Ships: A Material Flow Analysis for the Northern Aegean Basin

Marine-related activities contribute significantly to plastic pollution in oceans worldwide, particularly in regions located along international maritime routes such as Türkiye. The Dardanelles serves as a major maritime gateway connecting the Aegean Sea with both the Sea of Marmara and the Black Sea, enabling heavy vessel traffic that subsequently disperses plastic pollutants across large areas of the Mediterranean and beyond. Therefore, for the first time, this study applied material flow analysis to estimate potential sources and pathways of macro- and microplastics from 12 vessel categories, including fishing fleets, merchant ships, cruise liners, and military vessels in the Northern Aegean Sea. This approach provides insight into the range of sources and pathways, highlights priority areas for mitigation, and identifies additional knowledge gaps. Through material flow analysis–based estimations, general macro- and microplastic waste is found to be the largest contributor to marine plastic pollution, with an average of 14,965 tons/year, followed by antifouling particles at 5848.5 tons/year. Overall, this study presents a comprehensive evaluation of vessel-derived plastic pollution in a strategically significant maritime corridor and emphasizes its potential implications for the broader marine eco-system.