Long-Term Deterioration of Water Quality of the Mvoti Estuary, Kwazulu-Natal, South Africa

The Mvoti Estuary located on the eastern seaboard of South Africa is known for its poor water quality. In the present study, concentrations of dissolved oxygen (DO), ammonia, nitrates, chloride, sulphates, sodium and calcium were assessed together with conductivity and pH, compared to legislated guidelines and to previous studies of 1964 and 2000. The results indicate that with the exception of calcium, the Mvoti system has been experiencing long-term deterioration. Presently, ammonium ions, nitrate and chloride exceed the acceptable guideline target limits, and DO levels are extremely low. The biotic integrity of the system is therefore seriously compromised with the threat of detrimental effects to all users if mitigation measures aimed at improving water quality are not implemented.