Beach litter on the southern Baltic coast: Status after 10 years of MSFD implementation within Descriptor 10 - SUP directive and pandemic signs.

The research summarises 10 years of beach litter studies on the southern Baltic coast. Beach litter abundance in 2020-2024 was related to results from 2015 to 2019. Litter was collected from 15 sections (1 km) in four seasons yearly. The changes and trends in marine litter composition and sources were identified, taking into account the impact of the COVID-19 pandemic and the implementation of the Single Use Plastic (SUP) Directive (EU, 2019). In 2020-2024 litter classified as artificial polymer material was dominant along the studied beaches (64.3 %) with cigarette butts being the most commonly found litter type. 53.1 % of all litter came from tourism and recreational activities. The COVID-19 pandemic has reduced the beach litter abundance by about half in 2021 and 2022, mainly by lowering tourist activity. It is unclear whether the regulations resulting from the SUP Directive have significantly affected the amount of beach litter due to the masking effect of the pandemic, which coincided with the introduction of the Directive. However, it should be emphasised that the total number of SUP litter in 2020-2024, compared to 2015-2019, was lower by over 50 %. Moreover, cutlery, trays, straw and stirrers were not present in the top ten litter items in 2020-2024 as they were in 2015-2019. Based on the EU threshold value (20 items/100 m), Good Environmental Status (GES) was achieved in all assessed areas: the Eastern Gotland Basin Polish coastal waters (9.2 items/100 m), Bornholm Basin Polish coastal waters (16.6 items/100 m) and Gdańsk Basin Polish coastal waters (15.2 items/100 m) in 2016-2021.