Impact of Tea Processing Water Wastes on Phytoplankton Composition of Tshinane River, Limpopo Province

Abstract

The discharge of industrial waste water on freshwater resources is on the increase worldwide, including in South Africa. The study aimed at assessing the response of phytoplankton upon exposure to high levels of nutrients along the Tshinane River Limpopo Province. The study showed different phytoplankton assemblages with different changes in physico-chemical levels. Environmental factors do have a noticeable effect on phytoplankton abundance as it was shown by statistical analysis. Results computed by the Czekanowski coefficient showed that various environmental factors components contributed to the different composition and types of phytoplankton abundance (p<0.05). When environmental factors showed fluctuation (Increase or decrease) a different type of plankton was found to be tolerant to those levels. A total of 64 species were identified upstream and 103 species identified downstream. Phytoplankton spectrums were recorded from six taxonomic groups namely Chrysophyta, Dinophyta, Chlorophyta, Bacillariophyta, Cyanophyta and Dinophyta. The dominant taxonomic group was Chlorophyta (Downstream) and Bacillariophyta was the dominant phytoplankton upstream. The results supports the assumption that an increase in nutrients lead to a diverse phytoplankton species even if all the other parameters are within the South African Water Quality Range for Aquatic ecosystems. This shows that tea processing waste has a minimal impact on the ecosystem health of Tshinane River and the river is able to recover from the nutrient enrichment.