Torn, K.; Möller-Raid, T.; Herkül, K.; Suursaar, Ü.; Põldma, M., and Martin, G., 2024. Anthropogenic influence on coastal environments: Variation of beach litter in regions with diverse human activity. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 473-477. Charlotte (North Carolina), ISSN 0749-0208.

Marine debris and its accumulation on shorelines, also known as beach litter, is an increasingly acknowledged problem along the coastal areas. Beach litter abundance and composition was studied in 14 study sites along the 200 km stretch of the southern coast of the Gulf of Finland in springs of 2020 and 2023. The study methodology followed the guidelines of the UN Environment Programme UNEP/IOC. Multivariate ordination was used to elucidate the similarity structure of litter data between the sites. Nearly 5000 items of litter representing 10 different material categories were counted and their occurrences were studied in relation to the distances to major urban areas, shipping lanes, and exposures to prevailing winds, waves and currents. The highest amount (1492–2374 items/100 m) of litter was found on the beaches near the city centre of Tallinn, suggesting that the majority of the litter originated from local sources. Two out of the four suburban study sites also showed distinctive levels of litter (244–340 items/100 m). The smallest amount of litter (24–78 items/100 m) was mostly found in rural areas and on islands. The presence of litter on the islands suggests that the litter may have come from outside the local area, and overall pollution levels in the gulf, as the islands are uninhabited. Indeed, ca. 80% of labelled items found on island shores were of foreign origin. A large proportion of foreign product packaging on the shores of islands strongly indicated to the influence of shipping and currents. Usage of litter as bird nest material was also studied on the islands. It varied widely between zero and 67%. Plastic bags and food packaging were the predominant litter items on most of the beaches, while cigarette butts were also frequent near the city centre. The most frequently identified plastic types were cellulose acetate (CA), polyethylene (PE), and polypropylene (PP). Plastics composed of potentially toxic materials, such as polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PUR), and polycarbonate (PC), constituted 14% of the analysed plastics.