title: Effects of low concentrations of the phenylurea herbicide diuron on biofilm algae and bacteria.
abstract: 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.
authors: Institute of Aquatic Ecology, University of Girona, Faculty of Sciences, Campus Montilivi, Girona, Spain. martarivi@gmail.com
authors: Marta
authors: M
authors: Ricart
authors: Damià
authors: D
authors: Barceló
authors: Anita
authors: A
authors: Geiszinger
authors: Helena
authors: H
authors: Guasch
authors: Miren López
authors: ML
authors: de Alda
authors: Anna M
authors: AM
authors: Romaní
authors: Gemma
authors: G
authors: Vidal
authors: Marta
authors: M
authors: Villagrasa
authors: Sergi
authors: S
authors: Sabater
mesh_terms: D001419:Bacteria / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects*; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D004237:Diuron / Q000633:toxicity*; D056890:Eukaryota / Q000187:drug effects* / Q000502:physiology; D006540:Herbicides / Q000633:toxicity*; D007931:Leucyl Aminopeptidase / Q000378:metabolism; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D006540:Herbicides; D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D004237:Diuron; D007931:Leucyl Aminopeptidase; D000077194:Chlorophyll A