Oscillatoria simplicissima: an autecological study

Abstract

Oscillatoria simplicissima is a blue-green alga that was first observed in the Vaal River during 1984. It replaced Microcystis aeruginosa as the dominant blue-green algal species and became dominant after an increase in the organic phosphorus supply in the Loch Vaal catchment area to form algal blooms of great intensity. Although this blue-green alga is presumably non-toxic, a study over a seven-year period shows that it is one of the most important bloom-forming blue-green algal species in the Vaal River, interfering with recreational activities as well as water purification. During this study, environmental variables influencing the development of blue-green algae in a natural environment were studied in order to provide background information for growth studies of this group under controlled conditions. This paper gives an overview of an autecological study done on O. simplicissima in the Vaal River at Balkfontein, as well as the isolation and growth requirements of this blue-green alga under controlled conditions.


Water SA Vol.29(1) 2003: 105-112