Traunspurger, W.W.TraunspurgerSchäfer, H.H.SchäferRemde, A.A.Remde2022-03-032022-03-031996https://publica.fraunhofer.de/handle/publica/18803910.1016/0045-6535(96)00252-4In the present investigation the effect of the herbicide isoproturon on freshwater and sediment organisms was comparatively investigated in single species tests and a microcosm study. In single species tests the photosynthesis inhibitor isoproturon affected the growth rate of algae. For Chlamydomonas rheinhardi the EC50; i.e. the concentration, where the growth rate is inhibited to 50 per cent, was observed at 40 mu g/l. The growth rate of the ciliate Tetrahymena pyriformis was slightly inhibited at 700 mu g/l, whereas other heterotrophic organisms (Daphnia magna and the nematode Caenorhabditis elegans) were not affected by isoproturon up to concentrations of 1000 mu g/l. In the microcosm study application of isoproturon to the microcosms up to a concentration of 90 mu g/l neither affected the abundance nor the community composition of the phytoplankton, the zooplankton and the sediment dwelling nematodes. However, there was a distinct effect on anaerobic microbial degradation activity in the sediment.endediment organismfreshwater organismherbicide isoproturonmicrocosmstudysingle species test570610620660615journal article