Benthic macroinvertebrates and water quality assessment: Some toxicological considerations

Abstract

The distribution of benthic macroinvertebrates is generally considered to be indicative for the chemical quality of surface waters. However, little is known about their tolerance to chemical pollutants. To give further information on the tolerance of macrobenthos to toxic conditions of surface water, the susceptibility of invertebrate species of different taxonomical groups (Oligochaeta, Diptera, Hirudinea, Isopoda, Gastropoda, Tricladida, Hydrozoa, Heteroptera, Amphipoda, Odonata, Trichoptera, Ephemeroptera, Plecoptera) to 15 chemical compounds and to a mixture of organics concentrated from river Rhine water was determined in acute toxicity tests. The results indicated that the tolerance of macroinvertebrate species are pollutant-specific, whereas the differences in their susceptibility to toxic conditions due to pollution by several toxicants may be negligibly small. Therefore, the reliability of using biological systems based on the macrobenthos distribution to classify surface waters polluted with a variety of chemical pollutants should be seriously doubted.