|dc.description.abstract||Water is a scarce and precious resource in South Africa. Not only is the quality and quantity
of water available limited by climatic conditions but these resources are often impacted by domestic
and industrial effluents, as well as run-off from agriculture. Monitoring the aquatic environment
helps to determine the impact of various pollutants.
Chemical monitoring, important as it is, can only at best give a "snapshot" of water quality at
a particular moment in time. Biomonitoring in particular forms a vital part of monitoring programmes
as it gives a time integrated reflection of a particular pollutant or group of pollutants on the
Although diatoms have long been studied in South Africa, as well as being used in the past
to indicate water quality, the current suite of bioindicator organisms used in this country has not
until recently included diatoms, or any autotrophic organisms for that matter.
This body of work is presented with the aim of facilitating the use of diatoms as bioindicators
of water quality in South Africa. Methods for the collection, preparation and analysis of diatoms
have been collated and standardized. A number of European and other indices have been tested in
diverse localities for use in indicating recent and historical water quality. The impact of diffuse mine
effluent on diatom community structure has also been discussed. A new species common in
impacted waters (i.e. a potential indicator species for these conditions) has been described and a
guide to the common diatoms of South Africa is presented which, it is hoped, will be of use to those
who wish to commence with a study of South Africa's diatom flora.
The results of this study show that diatom indices are successful in reflecting both current
and past water quality in South Africa. This result justifies the inclusion of diatoms with the current
suite of bioindicator organisms as well as in national monitoring initiatives such as the River Health
Concluding comments underline the importance of using diatoms as indicators, not only of
water quality, but also as indicators of aquatic microorganism biodiversity, or loss thereof. The need
for continued research in the fields of diatom ecology and taxonomy is also highlighted.||