| 19580990 |
Ricart M, Barcelo D, Geiszinger A, Guasch H, de Alda ML, Romani AM, Vidal G, Villagrasa M, Sabater S: Effects of low concentrations of the phenylurea herbicide diuron on biofilm algae and bacteria. Chemosphere. 2009 Sep;76(10):1392-401. Epub 2009 Jul 5.
A system of recirculating channels was used in this study to examine the long-term effects (29d) of environmentally realistic concentrations of the herbicide diuron (from 0.07 to 7 microg L (-1)) on biofilm communities. The autotrophic activity of biofilms was affected by this herbicide, as reflected by a marked decrease in the photosynthetic efficiency. Diuron exposure also increased chlorophyll-a content and reduced the biovolume of diatom taxa at low concentrations. The effects on bacteria were also remarkable. Bacterial abundance was reduced after a week of exposure to the herbicide at a range of concentrations. Effects were on the number of live bacteria and on the increase in the leucine-aminopeptidase activity. It is suggested that inputs of herbicides to the river ecosystem at low concentrations may cause a chain of effects in the biofilm, which include inhibitory effects on algae but also indirect effects on the relationships between biofilm components. |
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