Linking microplastic pollution to coastal ecosystem connectivity and blue economy sustainability: Evidence from green mussels (

Microplastic pollution has become a major environmental concern in coastal ecosystems, particularly in areas with high anthropogenic pressure, such as Tambak Lorok, Semarang, Indonesia. This study aimed to investigate temporal variation in microplastic abundance in coastal waters and green mussels ( Perna viridis) and to identify their morphological and polymer characteristics. Sampling was conducted at three stations over a five-month period (May–September 2025). Microplastics were identified and classified into fibers, fragments, films, and pellets, while polymer types were analyzed using ATR-FTIR spectroscopy. The results showed that microplastics were consistently detected throughout the study period, with the highest abundance in water recorded in July (97 particles/L), indicating temporal variability influenced by environmental conditions and human activities. Fibers were the dominant microplastic type, followed by fragments, films, and pellets. ATR-FTIR analysis identified polypropylene (PP), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), and poly(diallyl phthalate), suggesting inputs from domestic, fisheries, port, and industrial activities. The occurrence of microplastics in green mussels and their temporal variation demonstrate connectivity between environmental and biological compartments. These findings highlight potential risks to seafood safety and emphasize the need for effective coastal management to support ecosystem resilience and a sustainable blue economy.