Transformation of sulfur species in lake sediments at Ardley Island and Fildes Peninsula, King George Island, Antarctic Peninsula.

Abstract

In Antarctica, penguins transport sulfur and other bio-elements in the form of guano from marine to terrestrial environments where they become deposited in ornithogenic soils and sediments, including lake or pond systems. Transformation of sulfur species in these terrestrial and aquatic deposits, however, has rarely been studied. Here, we used the cold diffusion method to analyze various sulfur species in a lake deposit of ornithogenic sediment core (C1) and a pristine lake sediment core (C2), collected from Ardley Island and Fildes Peninsula, Antarctic Peninsula, respectively. The total organic carbon, total phosphorus, total nitrogen and various sulfur species in C1 were more fluctuant and much higher than those in C2, indicating a primary source from penguin guano. In core C1, organic sulfur (Org-S) was the main form of sulfur, and sulfate (SO42-) was the main form of inorganic sulfur. The acid volatile sulfur (AVS) in C1 was much higher than pyrite sulfur (CRS). In the pristine lake sediment core C2, Org-S and SO42- were the main sulfur species. CRS was the primary form of reduced inorganic sulfur in C2 sediments in contrast to the AVS in C1, indicating that AVS had been effectively transformed into CRS in C1. Our results demonstrate that the high levels of organic matter in C1 likely limited the transformation of AVS to CRS.