Stefanie Knauert

Toxicity of Pesticides and Their Mixture to Primaryproducers: Laboratory and Semi-field Investigations on Thesingle Andjoint Toxicity of the ... Isoproturon, and Diuron Stefanie Knauert German edition

The earth's aquatic ecosystems are threatened by thecontamination with a multitude of anthropogenicchemical pollutants. Pesticides are one importantgroup of environmental contaminants. They are appliedin agriculture and can enter surface water bodies viaspray drift, drainage, run-off events and others. Consequently, pesticides are frequently detected inour surface waters and occur as single substancesand, more often, in mixtures of various compositions. There they may pose a risk to the aquatic ecosystems. The author focuses on single and joint toxicity ofthe four photosynthesis-inhibiting pesticides copper, atrazine, isoproturon, and diuron. To gain a betterunderstanding of the mechanism of phytotoxicity ofthe single pesticide copper, the role of reactiveoxygen species in copper toxicity was investigated indetailed laboratory experiments in two green algae. Moreover, an outdoor mesocosm experiment wasperformed to verify if the concept of concentrationaddition can predict the joint toxicity of the threeherbicides atrazine, isoproturon, and diuron tonatural phytoplankton communities under realisticenvironmental conditions.