DIATOM INDICATOR GROUPS IN THE ASSESSMENT OF WATER QUALITY IN THE JUKSKEI-CROCODILE RIVER SYSTEM (TRANSVAAL,REPUBLIC OF South Africa

SUMMARY

Based on a detailed study of Cholnoky's (1968) work in the ecology of diatoms, species with similar ecological requirements are arranged in groups. The use of these diatom groups as reliable indicators of the water quality in the Jukskei-Crocodile river system (Transvaal) is examined. The predictions of the water quality based on the diatom groups are compared with the chemical and a gal growth potential data. The results indicate that the diatom groups employed can serve as reliable indicators of water quality. In the present study they further suggest that the Modderfontein and Jukskei rivers arc considerably more eutrophied than the Hennops and Crocodile rivers.