CEST2025

Marine plastic pollution has well-recognised impacts in the loss of biodiversity and the degradation of coastal and marine ecosystems. Despite this, the threat of plastic pollution on seagrasses is still under-explored worldwide, compared to other marine species and habitats. Only recent efforts have been dedicated to this topic, with the first study published in 2017. Available literature highlighted that microplastics can affect seagrass plant growth, photosynthesis, nutrient cycling and habitat biodiversity, causing much concern. Few studies regard the endemic species Posidonia oceanica and investigated macro-/microplastics, only in the field (no laboratory experiments), mainly considered the plants alive instead of dead tissues. However, Posidonia beach wracks (i.e. banquette) are potential accumulation hot spots for microplastics and their monitoring can contribute to the plastic pollution assessment in Mediterranean coastal areas and improve the protection measures of P. oceanica habitats against the current plastic pollution crisis. To this end we setup and carried out in situ surveys and samplings of different banquettes across the Mediterranean basin: Favignana Island (Sicily, Italy); Akrotiri Bay (Cyprus); Sardinia (Italy), Lazio Region (Italy). The microplastic characterization in Posidonia leaf tissues by stereomicroscopy and Micro-Raman spectroscopy is in progress and results may provide important information about distribution patterns of microplastics and transfer dynamics between terrestrial and marine compartments.