Plastic Footprints: Evaluation of Microplastic Contamination in Oyster Bed Ecosystems in the Kingdom of Bahrain

This study provides the first comprehensive assessment of microplastic (MP) contamination within oyster bed ecosystems of the Kingdom of Bahrain. Sediment, water, and oyster samples were collected from six sites representing diverse environmental conditions. Raman spectroscopy identified the presence of 12 distinct polymer types, with polypropylene (PP), polyurethane (PU), poly(ethylene terephthalate)/diamine/multi-walled carbon nanotube (PET/diamine/MWCNT), and fluorinated ethylene propylene (FEP) being the most prevalent. MPs occurred predominantly as fragments, films, and pellets, with black being the most common color across all matrices. MP abundances ranged from 750 to 1850 MPs/kg dry weight in sediments, 2100–9600 MPs/L in water, and 1.78–5.25 MPs/individual in oysters, with particles (<50 µm) most frequent in oyster tissues. Although spatial variation was evident across regions, detected polymers included types associated with known ecotoxicological risks. No significant correlation was observed between sediment grain size and MP abundance, suggesting that additional hydrodynamic or anthropogenic factors may influence MP distribution. Overall, this study provides critical baseline data on MP contamination in Bahrain’s marine environments and highlights the need for continued monitoring to assess potential risks to marine ecosystems and seafood safety. It also contributes to the limited understanding of MPs in the Arabian Gulf, informing future monitoring, conservation and policy initiatives that support long-term environmental sustainability.