title: Phytotoxicity of atrazine, isoproturon, and diuron to submersed macrophytes in outdoor mesocosms.
abstract: The submersed macrophytes Elodea canadensis, Myriophyllum spicatum and Potamogeton lucens were constantly exposed over a five-week period to environmentally relevant concentrations of atrazine, isoproturon, diuron, and their mixture in outdoor mesocosms. Effects were evaluated investigating photosynthetic efficiency (PE) of the three macrophytes and growth of M. spicatum and E. canadensis. Adverse effects on PE were observed on days 2 and 5 after application. M. spicatum was found to be the more sensitive macrophyte. E. canadensis and P. lucens were less sensitive to atrazine, diuron and the mixture and insensitive to isoproturon. PE of M. spicatum was similarly affected by the single herbicides and the mixture demonstrating concentration addition. Growth of E. canadensis and M. spicatum was not reduced indicating that herbicide exposure did not impair plant development. Although PE measurements turned out to be a sensitive method to monitor PSII herbicides, plant growth remains the more relevant ecological endpoint in risk assessment.
authors: University of Basel, Department of Environmental Sciences, Hebelstrasse 1, 4056 Basel, Switzerland. stefanie.knauert@basf.com
authors: Stefanie
authors: S
authors: Knauert
authors: Heinz
authors: H
authors: Singer
authors: Juliane
authors: J
authors: Hollender
authors: Katja
authors: K
authors: Knauer
mesh_terms: D001280:Atrazine / Q000633:toxicity*; D004237:Diuron / Q000633:toxicity*; D031321:Hydrocharitaceae / Q000187:drug effects*; D010671:Phenylurea Compounds / Q000633:toxicity*; D031821:Potamogetonaceae / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010671:Phenylurea Compounds; D014874:Water Pollutants, Chemical; C028904:isoproturon; D004237:Diuron; D001280:Atrazine