The surface distributions of nutrients and chlorophyll a in the area between 90゜W and 20゜E of the Antarctic Ocean and adjacent seas

The surface distributions of chlorophyll a and nutrients were observed in the area between 90°W and 20°E of the Antarctic Ocean and adjacent seas in November and December 1984,and in January 1985,by R. V. KAIYO MARUas part of the national BIOMASS (SIBEX II) program. The mean concentrations of inorganic nutrients and chlorophyll a increase towared south from the Subtropical region to the Antarctic Ocean. Regional changes of phosphate and nitrate concentrations in the Antarctic water were small while those of silicate were large. High concentration of silicate (71±7μM) was found in the Weddell Sea, and the average atomic ratio of Si : N : P was 44 : 16 : 1. These high silicates may have resulted by upwelling from the deep water