AN EMPIRICAL BIOTIC INDEX OF THE QUALITY OF WATER IN SOUTH AFRICAN STREAMS AND RIVERS

摘要: Abstract A method of reducing data on stones-in-current faunal communities to a linear scale water quality in terms organic pollution is presented. Using from extensive river surveys each taxon has been allotted Quality Value (between 0 and 10) related its occurrence variously polluted waters. To arrive at the Biotic Index community, sample taken individual animals are recorded by taxa. The number individuals then multiplied taxon's Value. products these multiplications summed for this sum divided total whole give Values taxa occurring large numbers wide range qualities vary according diversity abundance Baetid Ephemeroptera. It not necessary identify all species level size critically important. compared with indices due other authors.