Microplastics in Turkish coastal lagoons: Unveiling the hidden threat to wetland ecosystems

Transitional ecosystems like coastal lagoons provide numerous ecosystem services. However, they are increasingly threatened by plastic pollution, particularly microplastics (MPs). Despite growing concerns, the occurrence and distribution of MPs in lagoon systems of Türkiye remain largely unknown. This study presents the first comprehensive assessment of MP pollution in five lagoons-Akyatan, Tuzla, Ağyatan, Çamlık, and Yelkoma-located in the northeastern Mediterranean region of Türkiye. A total of 15,526 MPs were recovered from water and sediment samples collected in November 2021 and June 2022. Water samples showed significantly higher MP concentrations in November (47.5 ± 4.02 MP/L) than in June (17.0 ± 2.57 MP/L). In contrast, sediment samples did not exhibit any statistically significant seasonal variation in MP abundance. The highest MP concentration in water samples was detected at Yelkoma (62.68 ± 12.76 MP/L), whereas sediment MP concentrations peaked in Akyatan Lagoon at 85.25 ± 27.96 MP/kg. Fibers were the dominant MP type, followed by fragments and films. Polymer analysis revealed polyethylene (PE), polypropylene (PP), and polyester (PES) as the most common types, indicating agricultural runoff, fishing gear, and mismanaged waste as significant pollution sources. These findings highlight the urgent need for targeted waste management strategies and long-term monitoring to mitigate MP pollution in these ecologically vital systems.