Distribution of Nutrients in the Western Bay of Bengal

Abstract

Distribution of phosphates and nitrates in relation to some physico-chemical features of the western Bay of Bengal during August-September 1976 indicated marked regional variations. The mixed surface layer which was associated with high oxygen and low nutrient concentrations increased in thickness from north to south. The intermediate water layer was marked by a steep rise of nutrients associated with oxygen minimum suggesting active decomposition of organic matter.N:P in the upper 75 m was considerably low ranging between 0 and 4.4 by atoms. Incontrast to this N:P in the depth range 100-1000 m showed somewhat higher values(6-7). Two regions of upwelling were observed, one near Visakhapatnam and the other near Madras.