PSM-Biodiv – Event-based recording and evaluation of diffuse pesticide inputs for biodiversity loss in Hessian watercourses
The destruction of habitats and increasing environmental pollution are leading to a significant loss of biodiversity in the watercourses and the adjacent floodplains. An important stressor for the aquatic biocenosis in intensively agricultural areas are the active substances of pesticides and their metabolites. The entry of pesticides into surface waters occurs mainly via surface runoff from fields during and after (heavy) rain events. However, according to the Water Framework Directive, the measuring of plant protection product active substances in the environment is carried out by the federal states completely independently of rain events and is based on the regular taking of grab samples. With this type of sampling, however, the mean and maximum pollutant concentrations are usually not adequately recorded and the total load from plant protection products is therefore often significantly underestimated. In addition, the sampling points for the routine measurements of water chemistry ordered by the authorities are usually located in larger watercourses, but at least just before the confluence of two bodies of water. As a result, the pesticide contamination of smaller watercourses, especially in agricultural landscapes, is not adequately recorded.
In order to be able to assess the actual pollution of water bodies with pesticides and the associated loss of species in the watercourses, new methods and solutions are required. The overarching goal of the project is the development of an innovative method of exposure monitoring that shows the real pollution of water bodies by pesticides and thus enables an assessment of the importance of pesticides for the loss of biodiversity in Hessian watercourses.
Automatic samplers will therefore be used in the project, which are located directly at the water body and which take high-resolution water samples in the event of precipitation. It is thus possible to record a pesticide wave and determine exactly how long limit values have been exceeded, for example concentrations that are acceptable for regulatory purposes. In addition, the active substances in pesticides and their metabolites are identified and quantified. In order to be able to estimate the ecotoxicological potential of the water samples, specific effect-based methods (EBM) are also used in the laboratory. EBM is understood to mean in vitro and in vivo investigations at the sub-organism and organism level, in order to depict, for example, the neurotoxic or endocrine potential of the active substances in the plant protection product in the water. The EBM also offer the advantage of recording mixture toxicity. As a result, causal relationships can be established between the pesticide load during (heavy) rain events and the observed effects, so that the role of pesticides in biodiversity loss can be better assessed and appropriate measures can ultimately be implemented.
Senckenberg Gesellschaft für Naturforschung
PD Dr. Andrea Sundermann
Phone: +49 (0) 6051 61954 3124
Dr. Matthias Oetken
Phone: +49 (0) 69 798 42148
Hessian Agency for Nature Conservation, Environment and Geology
Dr. Jens Mayer