学校対プラスチック：海洋ゴミとマイクロプラスチックに関する意識の高い学生の教育と研究支援

Plastic and microplastic (MP) pollution are critical environmental challenges, particularly in marine ecosystems. This study presents results from the Schools Against Plastics citizen science initiative, which engaged students from two Greek schools in coastal areas, Methoni and Palaia Fokaia, in monitoring plastic pollution. Under scientific guidance, students collected and analysed beach macro-litter and microplastics using a standardized toolkit. Macrolitter densities ranged from 0.6 to 5.9 items/m², with Methoni being cleaner, likely due to its remote, seasonal-tourism character compared to the more urban and heavily visited Palaia Fokaia. Plastics were the predominant material, with single-use plastics, especially bottle caps and cigarette butts, comprising over 25% of collected items, consistent with broader Mediterranean findings. MP concentrations in beach sand ranged from 4.6 MPs/kg to 102.5 MPs/kg. Polyethylene and polypropylene were the most common polymers, and pellets and fragments were the dominant shapes. Significant differences in weathering (FT-IR carbonyl index) were observed between shapes for each polymer type, suggesting potential variation in environmental exposure. Additionally, students participated in the sampling of a sea urchin (Paracentrotus lividus), while scientists conducted the analysis for ingested MPs. The results revealed an average of 1.6 and 2 MPs per individual for Methoni and P. Fokaia, respectively. Beach macro-litter and larger MPs can be effectively collected by non-experts under expert guidance, ensuring both the sustainability of the initiative and the reliability of the data. Schools Against Plastics demonstrates how citizen science can effectively support scientific research, enhance environmental education, and contribute valuable data to address marine plastic pollution.