Restriction of sulfate reduction on the bioavailability and toxicity of trace metals in Antarctic lake sediments.

In this study, Acid-Volatile Sulfur (AVS), trace metals Cu, Cd and Zn and their chemical speciation based on BCR-sequential and simultaneous extraction (SEMs) in Antarctic lake sediments (Y2-1 and YO) were analyzed to investigate the restriction of sulfate reduction on the bioavailability and toxicity of trace metals. Much higher trace metals in Y2-1 indicating a primary source from penguin guano. The main chemical speciation of Cu and Cd in Y2-1 was their oxidizable fraction in contrast to those of weak-acid extraction in YO.

Levels, sources and influence mechanisms of heavy metal contamination in topsoils in Mirror Peninsula, East Antarctica.

Heavy metal contaminants in Mirror Peninsula, East Antarctica, have rarely been studied and the source and influencing factors are poorly understood. We sampled a grid of 189 topsoil samples from Mirror Peninsula and analyzed the concentrations of Zn, Cu, U, Cr, Ga, Pb, Hg, Se and As; we also calculated the chemical index of alteration (CIA), a proxy of weathering. The results show that the distributions of Cr, Ga, Cu, and Zn are associated with weathering; the distributions of As and Pb are related to vehicle use and unloading activities at the wharfs, respectively; and the distribution of Hg is likely associated with both anthropogenic impacts and biological activity.

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

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.

Assessment of heavy metal contamination from penguins and anthropogenic activities on Fildes Peninsula and Ardley Island, Antarctic.

Fildes Peninsula, with a high density of scientific stations, has been significantly impacted by anthropogenic activities. However, the contamination from penguins, a biovector that transports pollutants from ocean to land, has seldom been assessed. In this study, 32 lacustrine surface sediment samples on Fildes Peninsula and 8 lacustrine surface sediment samples on Ardley Island were collected to determine Cu, Zn, Pb, Ni, Cr, Cd, Co, Sb, Hg and P levels.

Geochemical record of high emperor penguin populations during the Little Ice Age at Amanda Bay, Antarctica.

Emperor penguins (Aptenodytes forsteri) are sensitive to the Antarctic climate change because they breed on the fast sea ice. Studies of paleohistory for the emperor penguin are rare, due to the lack of archives on land. In this study, we obtained an emperor penguin ornithogenic sediment profile (PI) and performed geochronological, geochemical and stable isotope analyses on the sediments and feather remains.

Transport of nutrients and contaminants from ocean to island by emperor penguins from Amanda Bay, East Antarctic.

Penguins play important roles in the biogeochemical cycle between Antarctic Ocean and land ecosystems. The roles of emperor penguin Aptenodytes forsteri, however, are usually ignored because emperor penguin breeds in fast sea ice. In this study, we collected two sediment profiles (EPI and PI) from the N island near a large emperor penguin colony at Amanda Bay, East Antarctic and performed stable isotope and element analyses.