Microplastic pollution in waters of the Antarctic coastal environment of Potter Cove (25 de Mayo Island/King George Island, South Shetlands)

Abstract

Plastic pollution in the Southern Ocean around Antarctica is a growing concern, but many areas in this vast regionremain unexplored. This study provides the first comprehensive analysis of marine microplastic (MPs) concentrationsin Potter Cove, located near the Argentinian Carlini research station on 25 de Mayo/King George Island,Antarctica. Water samples were collected at 14 sites within the cove, representing various influences fromthe station´s activities. Two sampling methods were used: a 5 L Niskin bottle and an in-situ filtering device calledMicrofilter, allowing for large water volumes to be filtered. MPs were found in 100 % of the samples. Microfiltersamples ranged from 0.02 to 2.14 MPs/L, with a mean concentration of 0.44 ± 0.44 MPs/L. Niskin bottle samplesshowed concentrations from 0.40 to 55.67 MPs/L, with a mean concentration of 19.03 ± 18.21 MPs/L. Thedominant types of MPs were anthropogenic black, transparent, and pink microfibers (MFs) measuring between0.11 and 3.6 mm (Microfilter) and 0.06 to 7.96 mm (Niskin bottle), with a median length of 0.01 mm for bothmethods. Transparent and black irregular microfragments (MFRs) with diameters from 0.10 to 5.08 mm and amedian diameter of 0.49 mm were also prevalent. FTIR-spectroscopy revealed the presence of 14 types of polymers.Cellulose-based materials and polyethylene terephthalate were the most abundant in MFs, whilepolyurethanes and styrene-based copolymers dominated in MFRs. MPs were more abundant near the Carlini station.Compared to other coastal Antarctic areas, the MPs in the cove were relatively abundant and mostly smallerthan 1 mm. Local activities on the island were identified as the primary source of MPs in the cove, and the cyclonicwater circulation likely affects the distribution of small-sized particles. To protect the ecosystem, reducingplastic usage, improving waste management, regulating MPs debris, and enhancing wastewater practices are essential.