From macro to micro, from patchy to uniform: Analyzing plastic contamination along and across a sandy tide-less coast

Abstract In search of an effective method to evaluate plastic contamination, macrolitter (>25 mm), mesolitter (5–25 mm), large microlitter (2–5 mm), large and small microplastics (2–5 mm and 0.5–2 mm) abundances in surface beach sands were simultaneously determined by two methods in four beach zones at six locations along the 100-km-long marine coast of the Curonian Spit National Park and the neighboring cities. Mean (median) content of plastic items per m2 is 0.85 (0.33) for macro-, 1.48 (0.40) for meso-, 3.35 (0.68) for large microlitter, and 3235 (1800) for microplastics (0.5–5 mm). The distribution of litter and microplastics (0.5–5 mm) is highly variable along and across the beach. The abundance of small-microplastics (0.5–2 mm) at the beach face is similar for all the locations and replicates. Swash-zone mixing, water percolation, importance of sediment pore size (rather than grain size), natural sorting of plastic particles at the beach face are considered.