TURBIDITY AND OTHER PHYSICAL FACTORS IN NATAL ESTUARINE SYSTEMS PART 1: SELECTED ESTUARIES

Abstract

Data on turbidity and the factors influencing it, such as wind and substratum, were collected from eight representative estuaries along the Natal Coast. The results showed that Natal Estuaries can be divided into one of four groups, according to the turbidity regime present in the system, as either Clear (<10 Nephelometric Turbidity Units = NTU), Semi Turbid (10–50 NTU), Predominantly Turbid (51–80 NTU) and Very Turbid (>80 NTU). The influence of the tidal cycle on turbidity, salinity and temperature was also investigated. It was found that tidal action often creates gradients within a system. Turbidity gradients were more frequent in occurrence than either salinity or temperature gradients.