Marine Litter Pollution in Baltic Sea Beaches – Application of the Sand Rake Method

Abstract

Most marine litter monitoring methods used on beaches focus on macro-litter (>25 mm) only and show shortcomings regarding smaller litter classes (<25 mm), especially at Baltic Sea beaches. Therefore, we used a sand rake method developed for large micro- (2–5 mm), and meso- (5–25 mm) litter to quantify the overall pollution status of Baltic Sea beaches and to test if the method is useful in terms of the requirements of the Marine Strategy Framework Directive (MSFD). Between July 2017 and October 2019, 197 sand rake method surveys were carried out at 35 regions around the Baltic Sea. In total, 9345 litter pieces were found on an area of 10,271 m2 of which 69.9% were 2–25 mm in size. Artificial polymers (4921 litter pieces) were predominant (mean 52.7% ± 13.3). Abundance of litter was 0.91 pieces/m2 ± 1.50 (median 0.40 pieces/m2). The most common litter were industrial pellets (19.8%), non-identifiable plastic pieces 2–25 mm (17.3%), cigarette butts (15.3%), and paraffin (11.9%). At 15 surveys at the German North Sea island of Sylt the litter abundance ranged from 0.45 pieces/m2 (median) to 0.59 pieces/m2 ± 0.37 (mean). Here, 69.2% of the litter was 2–25 mm in size and paraffin was predominant (69.2%). Beaches show a high pollution level with large micro- and meso-litter (2–25 mm) and our data can serve as a Baltic-wide pollution baseline. In contrast to the naked eye OSPAR method for macro-litter, the sand rake method is generally applicable on all sandy beaches, both urban and remote. This method also allows for the provision of a full spatial pollution pattern and can serve for assessing the effectiveness of marine litter mitigation measures.

Environmental Impact of Geosynthetics in Coastal Protection

“…Since the fragments of plastics and geosynthetic materials were unevenly distributed on the beach, the use of a selective area technique for their search—such as, for example, for anthropogenic debris [ 24 ] and microplastics [ 25 ]—will not yield results. To analyze the pollution of the beaches at the Southeastern Baltic within the Kaliningrad Oblast (Russia), a continuous visual scanning technique [ 26 ] was applied which assumes a continuous passage of a group of several people along the entire coastline, covering the entire width of the beach from the shoreline to the foredune (or cliff).…”

Human impacts and their interactions in the Baltic Sea region

“…In the Baltic Sea, litter dropped at beaches is a major source for larger micro-to macroplastics, including cigarette butts (Haseler et al, 2020). Regarding the smaller size fractions, municipal waste water was identified as substantial source for 2210 microplastics into the Baltic Sea (Baresel and Olshammar, 2019;Schernewski et al, 2021), especially stormwater runoffs including sewer overflow events, wastewater treatment plants (despite relatively good removal efficiencies), and untreated wastewater.…”

“…The beaches of the Baltic Sea are significantly polluted with plastic particles, with reported numbers ranging between less than 10 to over 1000 plastic particles per kg dry weight (Urban-Malinga et al, 2020). An extensive survey of 190 sandy beaches across the whole Baltic Sea area yielded 4921 plastic particles >2mm, mostly industrial 2220 pellets (19.8 %), non-identifiable plastic pieces 2-25 mm (17.3 %), and cigarette butts (15.3 %) (Haseler et al, 2020). The Warnow estuary in the southern Baltic Sea, as an example for non-beach sediment, showed microplastic abundances (>0.5mm) https://doi.org/10.5194/esd-2021-54 Preprint.…”

“…• Coastal processes have no impact on the generation but a significant impact on the distribution and accumulations of beach wrack (Suursaar et al, 2014) and litter (+) on the shoreline (Esiukova, 2017;Haseler et al, 2020;Urban-Malinga et al, 2020). 710…”

“…Simultaneously, tourism was identified as a major pollution source on Baltic beaches (e.g. pieces from firework and cigarette butts) (Haseler et al, 2020;Schernewski et al, 2018) • There is presumably an impact on coastal management (? ), as plastic litter should be included in existing strategies.…”