Plastic contamination of sandy beaches along the southern Baltic – a one season field survey results

•Three size fractions of plastics were surveyed in coastal water and beach sediments.•Microplastics were dominated by 32 µm), large micro-/macroplastics (>2 mm) and plastic litter (visible by naked eye) contamination on sandy beaches and in coastal waters along the Polish coast of the Baltic Sea. Microplastics were studied with particular attention, with simultaneous observations in the water and across the beach. Other data was intended to serve as a background and as possible sources of microplastics. Most of the microplastics found were fibers