Comparative analyses of the chemical composition of water from Walvis Bay lagoon and Neudamm dam

Abstract

Abstract by author:

The chemical concentrations obtained in this study for lagoon, pond-1, pond-2 and Neudamm were as follow: pH 7. 81, 7. 79, 7. 86 and 7. 28, salinity (percent) 30. 5, 30. 83, 30. 73 and 0. 1, total alkalinity (mgCaCO3/l) 99. 5, 193. 03, 197, 01 and 154. 23, ammonia (umolNH4/l) 1. 951, 1. 251, 0. 696 and 0. 165, nitrate (umolNO3/l) 0. 756, 0. 013, 0. 653 and -0. 117, nitrite (umolNO2/l) 0. 139, 0, 191, 0. 837 and 0. 263, dissolved oxygen (mgO2/l) 4. 670, 6. 270, 5. 530 and 6. 290, hydrogen sulphide (umolH2S/l) 0. 154, 0. 283, 0. 154 and 0. 514, respectively. The high concentration of nitrite found in pond-2 may be toxic to the oysters, however, other substances were moderate and may not affect oysters' survival. Hydrogen sulphide was high in Neudamm dam but fortunately this water body is not used for oyster cultivation. The chemical composition was found to be different between fresh water bodies and marine water