Microplastics in Antarctic krill (Euphausia superba) from Antarctic region

Area of Science:

• Marine Biology
• Environmental Science
• Ecotoxicology

Background:

• Microplastic (MP) pollution poses a significant threat to marine ecosystems globally.
• Antarctic marine ecosystems, particularly keystone species like Antarctic krill (Euphausia superba), are vulnerable to MP contamination.
• Limited data exists on the presence and characteristics of MPs within Antarctic krill populations.

Purpose of the Study:

• To investigate the abundance and characteristics of microplastics (MPs) in Antarctic krill (Euphausia superba).
• To assess the potential ecological risks posed by MP ingestion in this crucial Antarctic species.

Main Methods:

• Collection of Antarctic krill samples (n=437) from the South Shetland and South Orkney Islands.
• Extraction of MPs using an alkali digestion method.
• Analysis of MP characteristics (size, shape, color, polymer type) via Fourier-transform infrared spectroscopy.

Main Results:

• MPs were detected in Antarctic krill, with mean abundances of 0.29 items/individual (South Shetland Islands) and 0.20 items/individual (South Orkney Islands).
• Over 90% of detected MPs were smaller than 150 μm, primarily in the form of fibers (77-87%).
• Predominant MP colors were black, blue, and red, with polyethylene, polypropylene, and polyester as the most common polymer types.

Conclusions:

• This is the first study to document microplastic occurrence in Antarctic krill.
• The findings indicate widespread MP contamination in Antarctic krill, with a prevalence of small-sized fibers.
• Results are crucial for assessing the ecological risks and impacts of microplastic pollution on Antarctic marine food webs.