Temporal series of coastal antarctic bacterial communities. Inputs, Amplification and Sinks of PFAS at Coastal Antarctica

A large data set of perfluoroalkyl substances (PFAS) in the maritime Antarctica shows the relevance of amplification processes, as well the biogeochemical controls on their occurrence in coastal waters. The largest number of targeted PFAS could be quantified in atmospheric-derived samples (aerosols, rain, snow), consistent with the importance of wet deposition as an input of PFAS to the maritime Antarctica. Such deposition of PFAS is unequivocally demonstrated by the occurrence of PFAS in small Antarctic lakes. Several lines of evidences support the role that the amplification of PFAS concentrations driven by snow-melting play at coastal seawaters, as well by penguins close to their colonies. The levels of PFAS were higher in Deception island than Livingston island consistent with the semi enclosed nature of their waters, and potential larger number of tourist at Deception. The levels of some PFAS, such as PFOS and PFOA, have decreased during the last years. While the biological pump is a sink of PFAS to the sediment in this high-biological productivity region, it is unlikely to drive this decrease in concentrations alone. The potential role of microbial degradation is explored by the combined assessment of PFAS dissolved and plankton phase concentrations and the composition and abundance of the bacterial community. Interestingly, there are a number of bacterial groups correlated with PFAS concentrations. The potential role of these and other marine bacteria taxa on the ultimate fate of PFAS should be a research priority in the coming future.