Vertical distribution of nutrients and DOC in lake waters near Syowa Station, Antarctica

Abstract

The vertical distribution of inorganic nutrients and DOC (dissolved organic carbon) was determined for two freshwater and three saline lakes near Syowa Station in January to February, 1977. In the freshwater lakes of O-like and Skallen Oike, the concentrations of nutrients were very low and their distributions were vertically homogeneous. Saline lakes of Nurume and Suribati, were typically meromictic and anoxic below 10m depth. In the anoxic layers of these lakes, PO_4-P and NH_4-N were highly concentrated. These nutrients were probably originated from the decomposition of organic materials in the bottom sediments. The concentrations of nutrients in Lake Hunazoko, which is the most saline lake around Syowa Station, were considerably lower than those of Lakes Nurume and Suribati except for SiO_2-Si. The concentration of DOC in the water of the freshwater and saline lakes ranged from 0.84 to 2.84mg/l and from 1.63 to 186mg/l, respectively. The highest value of DOC was found in the bottom of Lake Hunazoko. In the saline lakes studied, a significant correlation was found between chlorinity and DOC. This result may suggest that the high concentration of DOC in these lakes is attributable to concentration of sea water under freezing conditions.