Microplastic concentration and composition in surface waters of the Weddell Sea, Antarctica

The dataset provides information about the microplastic contamination in surface waters of the Weddell Sea, Antarctica. Samples (n = 34) were collected during two expeditions on RV Polarstern, PS111 (2018) and PS117 (2018/2019), to the Antarctic Weddell Sea, taking place during austral summer. Samples were collected with a surface trawl (manta trawl; 5gyres Institute, Los Angeles, California; 60 x18 cm² rectangular aperture) equipped with a 300 µm mesh and a mechanical flowmeter. On average 234.6 (±83.7 SD) m³ of seawater were filtered per sample (total filtered volume: 7974 m³). Putative microplastic particles were sorted visually under a dissecting microscope (magnification 6.7-45x) and analyzed by means of by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy.