Microplastics in Lake Sediments in Robert Island, Antarctica

Abstract

Microplastic (MP) pollution was investigated in the sediment of lakes on Robert Island in the South Shetland Islands located in the northwest of the Antarctic Peninsula. Sediment samples were taken from a glacial lake (L1) and three coastal lakes (L2, L3 and L4) in March and April 2018 as part of the Turkish Antarctic Science Expedition-II (TAE-II). MPs were counted, and physically (shape, colour, size) and chemically characterized by stereomicroscope and Fourier-transform infrared spectroscopy (FT-IR) respecitvely. Fibers and fragments were found in the coastal lakes, while only fibers were found in the glacial lake sediment. The meanMP concentration was 28.3 mp. L-1±37.9 mp. l-1 sediment in the glacial lake and 49.6 mp. l-1±97.1 mp. l-1 sediment in coastal lakes. A total of six different colours of MPs were found with transparent and blue were dominant. The size of MPs varied between 0.08-2.12 mm (mean 0.96±0.55 mm). FT-IR analysis confirmed that MPs were composed of Ethylene Vinyl Acetate (EVA), Polyethylene terephthalate (PET), Polypropylene (PP), Polymethyl Methacrylate (PMMA), Polyethylene (PE), Polyurethane (PU), and Polyacrylonitrile (PAN). Presence of MPs in the lake’s sediment highlights the vulnerability of Antarctica's environment to this unbounded and unpredictable pervasive pollutant and raises concerns about the potential effects of MPs on its unique ecosystems, which are critical to global climate regulation. More comprehensive research on distribution, characteristics, sources and transport of MPs in this remote region is recommended to fully understand the level of risk that MPs represents to ecosystem health.