Spatial and seasonal variability of beach litter along the southern coast of the Baltic Sea in 2015–2019 - Recommendations for the environmental status assessment and measures

Abstract

The main aim of the research was to analyse the variability of the beach litter items, both in terms of categories and top items collected on the southern Baltic coast, based on a 5-year series of data. Research on beach litter collected in 15 sections with a length of 1 km in four seasons has shown that the dominant is artificial polymer materials with the percentage share of 68.5%. The proportions of other categories were at the levels of 10% in the case of processed/worked wood, 8% - metal, 4% - glass/ceramics and paper/cardboard, 2% - cloths/textiles and 1% - rubber. Unidentified items constituted about 3%. 53% of the top 10 litter types were cigarette butts and filters. Linking the litter types with their potential sources allowed for the identification of tourism and recreational activities as the main source with the percentage from 58.1% to 71.6%. There is no clear link between the number of tourists and the amount of litter, mainly due to the beach clean-up companies coordinated by local authorities. A comparison of urban and rural areas showed differences in the total beach litter number, while the percentage share of individual categories and litter sources was similar. The marine environment's status in terms of beach litter was assessed based on national and EU threshold values. The assessment based on the national threshold values indicates the poor environmental conditions along the southern Baltic coast, regarding both total number litter items per 100 m and artificial polymer materials. In the case of assessments based on the EU threshold value set - for the total number of litter per 100 m the environmental status of the southern Baltic coast was considered good throughout the entire study period.