Prevalence of Fibers as the Dominant Microplastic Fraction in the Digestive Tract of Three Commercially Important Fish Species ( Sparus aurata Linneaeus 1758, Pagellus erythrinus Linneaeus 1758 and Chelon auratus Risso, 1810) from the Southeastern Coast of Istria, Northern Adriatic, Croatia Prevalencija vlakana kao dominantne mikroplastične frakcije u probavnom traktu triju komercijalno važnih vrsta riba (Sparus aurata Linneaeus 1758, Pagellus erythrinus Linneaeus 1758 i Chelon auratus Risso, 1810) s jugoistočne obale Istre, Sjeverni Jadran, Hrvatska

The exponential increase in plastic pollution, especially microplastics (MPs), is closely linked to human population growth, industrialization, and poor waste management practices. MPs have become a pervasive environmental contaminant, posing significant risks due to their ability to adsorb harmful substances and attached microorganisms. The Adriatic Sea is a critical region for studying microplastic pollution, ranking among Europe's three most polluted seas, with plastic comprising 80% of waste. This study investigates the presence of MPs in three commercially important fish species- Gilthead seabream ( Sparus aurata), Common pandora ( Pagellus erythrinus), and Golden grey mullet ( Chelon auratus)- collected from the northern Adriatic Sea. A total of 93 fish were analyzed, revealing that all extracted MPs were fibers, primarily black (42.4%) and blue (39.6%). The results indicate the higher MP contamination levels (80.64%) of S. aurata and C. auratus when compared to P. erythrinus (35.48%). This research contributes to a better understanding of microplastic pollution in the region and can improve the knowledge for effective monitoring and mitigation strategies. Future studies should focus on the longterm impacts of MPs on marine ecosystems and human health, particularly in commercially consumed species.