No evidence of microplastics in Antarctic fur seal scats from a hotspot of human activity in Western Antarctica

Abstract

Microplastics are present in almost all seas and oceans, including the Southern Ocean. To the south of the Antarctic Polar Front, microplastics are present mainly west to the Antarctic Peninsula, but information is scarce about their impact on the pelagic food web. Here, we analysed 42 scats of male Antarctic fur seals (Arctocephalus gazella) collected in late summer at Deception Island (South Shetland Islands), which allowed us to assess the presence of microplastics in the pelagic food web of the Bransfield Strait (Western Antarctica). Furthermore, we analysed the hard remains of prey in the scats to characterize the diet of fur seals. Hard remains recovered from the scats revealed that male Antarctic fur seals foraged on krill and myctophid fishes during late summer. Fourier-transform infrared spectroscopy (FT-IR) revealed that none of the seven fragments and three fibres recovered from their scats were microplastics, but rather were silicate minerals and chitin. These results suggest that the levels of microplastic pollution in the pelagic food web of the Bransfield Strait are extremely low.