Assessing marine macrolitter on the coastline of the Asterousia Biosphere Reserve: Insights from a community-based study.

Even in pristine and remote environments of the Mediterranean, marine litter is building up threatening habitats and species and inhibiting sustainable development. The present study reports the findings of beach litter surveys carried out by 250 local community members in nine sites along the coastline of the Asterousia Biosphere Reserve, situated in the southernmost end of Europe. The average recorded litter density along these sites amounted to 125 items per 100 meters of coastline (range: 22–510) and to 0.05 items per square meter of beach (range: 0.01–0.13). Only two of the nine surveyed beaches were found to be in good environmental status, in compliance with the European threshold value for beach litter. The other seven studied beaches surpassed the European threshold value. The primary sources of the litter identified in the study can be attributed to unsustainable practices and inadequate waste management by individuals, communities and municipalities using the coastal and marine environment. Additionally, unsustainable waste management practices within the agricultural sector were also found to be a significant contributor to marine litter pollution. • Participatory-science is an effective tool for generating fit-for-purpose beach litter data. • The majority of traceable marine litter items in the study area originate from shoreline sources. • The vast majority of litter items are plastics, accounting for 86 % of all litter collected. • Single-use plastics account for a large fraction of the recorded items. [ABSTRACT FROM AUTHOR]