Seawater samples from the surface as well as at different depths of the water column were collected from 30 stations during the Pilot Expedition to Southern Ocean (PESO). The sampling stations were along a transect between latitude 27 degrees 59 minutes 48” S and 56 degrees 00 minutes 14" S and longitude 50 degrees E and 45 minutes E in the Indian Ocean Sector of the Southern Ocean. An attempt has been made to study the nutrient distribution in the water column. The physico-chemical parameters like pH, surface temperature and surface dissolved oxygen have also been studied. The results are useful to infer the mixing of different water mass and distribution of nutrients in the surface and below surface water column. A first order comparison of surface water physico-chemical parameters in the study area with the planktic foraminiferal abundance shows a profound influence of seawater pH on the planktic foraminiferal abundance in the southwestern Indian Ocean.