Distribution of 90Sr and 137Cs in biotic and abiotic elements of the coastal zone of the King George Island (South Shetland Archipelago, Antarctic Peninsula)

Abstract

For many years Antarctic ecosystems have been considered pristine, however recent studies, including our results, contradict this assumption. Our comprehensive study on the activity of anthropogenic radioisotopes (¹³⁷Cs and ⁹⁰Sr) in the most common species of green algae, bryophytes, lichens, and vascular plants, as well as soil and guano samples collected over a large area on King George Island (South Shetland Archipelago) in the austral summer 2018/2019 clearly indicate the importance of large-scale transport in shaping the level of pollution in areas very distant from potential sources of contamination. Additionally, radioisotope pollution can be measured even after a very long period (>60 years) since their occurrence. The mean activity of ¹³⁷Cs measured in lichens, bryophytes, vascular plants, green algae, soil, and guano was, respectively: 3.72 Bq kg^-1_dw, 3.70 Bq kg^-1_dw, 2.62 Bq kg^-1_dw, 2.26 Bq kg^-1_dw, 4.07 Bq kg^-1_dw and 2.08 Bq kg^-1_dw. For ⁹⁰Sr mean activity in lichens, bryophytes, vascular plants, green algae, and soil was, respectively: 1.99 Bq kg^-1_dw, 3.05 Bq kg^-1_dw, 2.42 Bq kg^-1_dw, 1.08 Bq kg^-1_dw, and 6.43 Bq kg^-1_dw. Increased activities of ⁹⁰Sr and ¹³⁷Cs were observed in species collected in the area influenced by glacier melt and penguin guano.

Keywords: Antarctic; Cryptogamic species; Radioactive pollution; Vegetation.