Single-use plastic free islands: The case study of Donousa

This study investigates the impact of the four-year cleaning and awareness raising program implemented on Donousa, the first island in Greece to ban single-use plastics. Despite the relatively low marine macro-litter recorded levels, approximately 90 % of the collected items were composed of artificial polymer materials. According to the plastic’s Clean Coast Index analysis, the surveyed beaches transitioned from “very clean” or “clean” state in 2018 to a “moderate” state in 2021, mostly influenced by items transferred by sea currents, like plastic fragments ≥ 2.5 cm, which ranked as the primary litter type on Donousa. While most of the collected marine litter were of uncertain origin (55.7 %), land-based sources (2.5 %) found to be the least prominent, with fishing activity (16.8 %) and beach users (26.0 %) contributing significantly. Regarding the single-use plastic (SUP) items, that the program specifically targeted to reduce by transitioning to alternative options, their contribution to the total plastic marine litter load decreased by 11.2 % by the end of the program, with plastic bottles nearly eliminated. Notably, beach S 4 recorded a 34.6 % reduction in SUPs . However, challenges persist with item categories such as caps/lids, cigarette butts and plastic bags, highlighting the urgency for more drastic preventive measures and coordinated interventions on a larger scale. • The presence of single-use items on Donousa decreased by 11 % over the program period • The 13 % reduction in beach users related plastic litter highlights the positive impact of awareness and educational campaigns. • The most abundant single-use plastic items were cigarette butts, plastic caps/lids and bags. • The contribution of single-use plastics to marine litter did not increase during Covid-19 pandemic. • The frequent reoccurrence of plastic fragments suggests sea transferred waste.