The sediments of lake on the Ardley Island, Antarctica: Identification of penguin-dropping soil

During CHINARE 15(Dec. 1998 Mar. 1999), a lake core 67.5 cm in length, was sampled in Y2 lake, which is located on the Ardley Island, Antarctica. The concentrations of some chemical elements in Y2 lake sediments were analyzed. According to comparative research on elementary characters of sediments in Antarctic West Lake, fresh penguin dropping as well as guano soil on the Ardley Island and Pacific Island in South China Sea, it presents that the Y2 lake sediments were ameliorated by penguin dropping. The result of element cluster analysis shows that the type elements in the sediment impacted by penguin dropping include Sr,F,S,P,Ca,Se,Cu,Zn and Ba. This can provide a base for further interpreting the climatic and environmental event recorded in the sediment.

Sources and distribution of particulate organic carbon in Great Wall Cove and Ardley Cove, King George Island, West Antarctica

Concentrations of chlorophyll-a（Chl-a）, particulate organic carbon（POC） and its stable carbon isotope composition（δ13C） were analyzed to investigate the biogeochemical characteristics and sources of POC in Great Wall Cove（GWC） and Ardley Cove（AC） during the austral summer. POC concentrations ranged from 50.51 to 115.41 μg·L^-1（mean±1 standard deviation： 77.69±17.27 μg·L^-1） in GWC and from 63.42 to 101.79 μg·L^-1（82.67±11.83 μg·L^-1） in AC. The POC δ13C ranged from-30.83‰ to-26.12‰（-27.40‰±0.96‰） in GWC and from-28.21‰ to-26.65‰（-27.45‰±0.47‰） in AC. The temperature and salinity results showed distinct runoff signals in both GWC and AC, although the δ13C data and POC distribution indicate a negligible influence of land sources upon POC. The δ13C values suggest that POC is of predominantly marine origin. The POC/Chl-a ratio and the relationship between POC and Chl-a indicate that phytoplankton, organic detritus and heterotrophic organisms are significant contributors to POC in GWC and AC.

Seawater nutrient and chlorophyll α distributions near the Great Wall Station, Antarctica

We examined the influences upon nutrient, temperature, salinity and chlorophyll a distributions in Great Wall Cove（GWC） and Ardley Cove（AC）, near the Chinese Antarctic Great Wall Station, using measurements taken in January 2013 and other recent data. Nutrient concentrations were high, with phosphate concentrations of 1.94（GWC） and 1.96（AC） μmol·L-1, DIN（dissolved inorganic nitrogen） concentrations of 26.36（GWC） and 25.94（AC） μmol·L-1 and silicate concentrations of 78.6（GWC） and 79.3（AC） μmol·L-1. However, average concentrations of chlorophyll a were low（1.29 μg·L-1, GWC and 1.08 μg·L-1, AC）, indicating that this region is a high-nutrient and low-chlorophyll（HNLC） area. Nutrient concentrations of freshwater（stream and snowmelt） discharge into GWC and AC in the austral summer are low, meaning freshwater discharge dilutes the nutrient concentrations in the two coves. Strong intrusion of nutrient-rich water from the Bransfield Current in the south was the main source of nutrients in GWC and AC. Low water temperature and strong wind-induced turbulence and instability in the upper layers of the water column were the two main factors that caused the low phytoplankton biomass during the austral summer.