Surface microplastics on Cymodocea nodosa and Ruppia maritima leaves: a study in Vravrona Wetland, Greece

This study investigates the seasonal accumulation of microplastics on the leaves of two marine angiosperms – Cymodocea nodosa and Ruppia maritima – in the Vravrona Wetland, Greece. These plants are essential to coastal ecosystems, providing habitat, stabilizing sediments, and enhancing water quality. However, they may face growing threats from plastic pollution. Microplastic (MP) concentrations ranged from 1.14 to 2.41 MPs/cm2 on C. nodosa and from 2.82 to 5.6 MPs/cm2 on R. maritima leaves, with synthetic fibers being the predominant type. These values significantly exceed previously reported microplastic densities on the leaves of other marine angiosperms. Notably, microplastic density per leaf area showed an inverse seasonal pattern relative to leaf size, with stronger correlations to leaf area rather than epiphytic cover. This study highlights how the aboveground structures of these plants trap microplastics, potentially introducing them into the food web via herbivorous marine species and disrupting nutrient dynamics. These findings stress the urgent need to protect marine angiosperm meadows in tackling the growing issue of plastic pollution.