Analysis and pre-estimation of nutrients in Vietnamese waters

Abstract

The distribution of nutrients (Silica, Phosphate, Ammonium, Nitrate, Nitrite and Sulfate) in the Vietnamese waters was studied in the SEAFDEC Interdepartmental Collaborative Research Survey: Area IV. The samples were collected by M.V. SEAFDEC on the 30 April to 29 May 1999 (post monsoon period). Fifty-eight stations (2m from surface and 100 m from surface) were established in this study. The average of Silica at the surface layer is 25.96μM and at the bottom layer is 30.69μM. The average of Phosphate at the surface layer is 0.890 μM and at the bottom layer is 1.353μM. The average of Ammonium at the surface layer is 2.805μM and at the bottom layer is 2.538μM. The average of Nitrate at the surface layer is 5.593μM and at the bottom layer is 6.810μM. The average of Nitrite at the surface layer is 0.169μM and at the bottom layer is 0.197µM. The average of Sulfate at the surface layer is 26.903 μM and at the bottom layer is 27.831μM. The results indicated that the concentrations of Silica, Phosphate, Nitrate, Nitrite and Sulfate in deep water were higher in the surface water, but the Ammonium is inverse.