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Anthropocentric impacts on the ecology and biodiversity of the Natalspruit watercourse and its associated wetlandsKruger-Franck, Elmarie 07 1900 (has links)
Information regarding the ecological wellbeing of the Natalspruit and its adjoining wetlands is
essential if the river is being managed using sound ecological management principles. Despite
this, little is known about this river, with little documentation at the regional or municipal level.
This study partially addresses this knowledge gap by evaluating the impacts of human activity
on a section of the Natalspruit and its adjoining wetlands. It reports on pollution concentrations
found at selected sample sites and compares the results to Rand Water data and the National
Standards and Guidelines of South Africa for physicochemical parameters and contaminated
soils. Water samples were collected at five chosen sample sites during May and July 2018. Soil
samples were taken during July 2018. The study found that water at all five sample sites is not
suitable for drinking, the health of livestock and recreational use due to the present and high
Total Coliform levels (ranging from 450 CFU/100ml to 100 000 CFU/100ml), as well as
Turbidity, Total Hardness, TDS, Mg, NO2, SO4, and BOD which also exceeded the guidelines.
Only site SS1 (May) exceeded the CaCO3 concentrations regarding livestock health. No
guidelines were available for DO levels on the health of livestock. Cl levels in the Natalspruit
was suitable for drinking. PO4 concentration at all the sites were all within the guidelines of
acceptable levels for aquatic ecosystems. In terms of heavy metals, Cr levels significantly
exceeded the guidelines at all five sample sites with the exception of ecosystem health. This is
of great concern due to the toxicity of Cr. Cu concentrations exceeded the guidelines for both
all land-uses protective of water resources and ecosystem health, at SS1, SS2, SS3 and SS5. Ni
concentrations exceeded the guidelines for all land-uses protective of the water resources at
SS5. Pb and Zn concentrations exceeded the guidelines for the land-uses protective of the water
resources at all the sites with the exception of SS4 for Pb and SS2 and SS4. SS1 and SS5
reported Zn concentrations higher than the guideline for the protection of ecosystem health.
SASS 5, PES and EIS assessments indicated moderate to severe modifications of the river.
Thus, mining, industrial activities, surface runoff from densely populated informal settlements and wastewater treatment plants have negatively impacted upon the river. Decades of
environmental neglect and effluent discharge have degraded the ecosystem, thus necessitating
rehabilitation. However, as the study was limited in both time and scope, so additional research
should be undertaken. / Environmental Sciences / M. Sc. (Environmental Management)
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