Occurrence and distribution of microplastics in intertidal sediments at Deception Island, Antarctica

Microplastic contamination is a well-recognized threat to marine ecosystems, yet its occurrence in remote regions, such as Antarctica, remains poorly documented. This study presents a preliminary assessment of microplastics in intertidal sediments from beaches on Deception Island, South Shetland Islands, Antarctica. Surface sediment samples were collected from the upper intertidal zone and processed using Sediment Microplastic Isolation (SMI) units. Polymer composition was determined by Fourier Transform Infrared (FTIR) spectroscopy, while particle morphology and color were analyzed using ImageJ-Fiji software. Microplastic concentrations ranged from 2.22 to 31.09 items·kg^-1, with the highest value recorded at Whalers Bay. Polyethylene (PE, 40.83%) and polyvinyl chloride (PVC, 28.57%) were the most abundant polymers. Fragments dominated (73.91%), followed by films (21.74%), and particle sizes ranged from 0.24 to 0.50 mm (mean ± SD: 1.29 ± 0.42 mm). Amber, green, and grey were the most frequent colors. No significant correlation was observed between microplastic abundance and sediment grain size. These results provide the first evidence of microplastics in the intertidal zone of Deception Island, establishing a baseline for future monitoring and contributing to a broader understanding of plastic contamination in Antarctic coastal environments.