Microplastics in Antarctic krill (Euphausia superba) from Antarctic region

Pollution of microplastics (MPs) has become a potential threat to Antarctic marine ecosystems. However, the occur-rence of MPs in Antarctic krill (Euphausia superba), a keystone species in Antarctic ecosystems, remains unclear. In this study, the abundance and characteristics of MPs were examined in Antarctic krill samples (n = 437) collected from two Antarctic regions. MPs were extracted using an alkali digestion method and analyzed using Fourier-transform infrared spectroscopy. The mean abundance of MPs in Antarctic krill samples from the South Shetland Islands (n = 355) and the South Orkney Islands (n = 82) were 0.29 +/- 0.14 and 0.20 +/- 0.083 items/individual, re-spectively. >90 % of MPs found in Antarctic krill were < 150 mu m in size. Fibers represented 77 % and 87 % of the MPs in Antarctic krill samples from the South Shetland Islands and the South Orkney Islands, respectively. Black, blue, and red were the predominant colors of MPs in Antarctic krill, accounting for 32 %, 22 %, and 21 % of the total MPs, re-spectively. Seven polymer compositions were identified for the MPs in Antarctic krill, with the predominance of poly-ethylene (37 % of total MPs), followed by polypropylene (22 %) and polyester (21 %). To our knowledge, this is the first study to investigate the occurrence of MPs in Antarctic krill samples. The results of this study are important for evaluating the risks of MP exposure in Antarctic krill.

Automated summary

This study examined the abundance and characteristics of microplastics (MPs) in Antarctic krill samples. The results showed that MPs mainly existed in fiber form, with black, blue, and red as the predominant colors. The predominant polymer compositions were polyethylene, polypropylene, and polyester. This is the first study to investigate the occurrence of MPs in Antarctic krill samples and is important for evaluating the risks of MP exposure in Antarctic krill.