Quantifying microplastics concentration of invertebrates from three Antarctic fjords

Microplastics, small pieces of plastic measuring less than five millimeters, have spread to all ecosystems, even those in the Southern Ocean around Antarctica. In particular, microplastics have been found contaminating water in emerging fjords, or inlets created by deglaciation, along the Antarctic Peninsula. Microplastics contamination puts fjord communities, which are unique and dominated by benthic species, at high risk for microplastic exposure leading to issues with feeding, endocrine disruption, and exposure to adsorbed toxins, all of which lower fecundity and survivability. The objective of this study was to quantify microplastics in invertebrates grouped according to feeding type. Invertebrates were collected from the Western Antarctic Peninsula fjords during 2017 and 2020 from three fjords via a mini-Agassiz trawl to quantify microplastic concentrations and identify polymer composition using Micro-ATR-FTIR. In 2017, 2.39 microplastics individual were identified, while 5.01 microplastics individual were identified in 2020. Out of the 24 polymers and polymer associates identified, the most common polymers were polypropylene, polycarbonate, polyamide, and polystyrene. Overall, the most common microplastic color category was black/brown/gblay, and fragments were the most common shape identified. Microplastics presence was significantly higher in the invertebrate organisms compared to procedural blanks (p < 0.001), but feeding mechanism was not found to be a predictor of microplastic bioaccumulation. Microplastics concentrations in invertebrates differed between fjords in 2017 (p = 0.010) but not in 2020. Complementing previous research on microplastics in Southern Ocean fjordic water, this study reveals new evidence of microplastics in Antarctic fjordic inhabitants.