Pilot study on effects of glyphosate on aquatic organisms has started
In Austria the application of pesticides amount for 3275 t per year whereas 50 % account for herbicides. These can also be transported into freshwater ecosystems via direct introduction or via erosion during rainfall events. Once in the system, some herbicides and their metabolites accumulate in sediments or in ecosystem primary producers. Consequently, they may create trophic cascades, with differing indirect effects to herbivorous and predator organisms, depending on the type of herbicide and its Mode of Action. Bioaccumulation of herbicide substances may lead to chronic toxicity to the organisms accumulating substances and to their predators. Several studies have assessed the direct effects of herbicides on non-target organisms but the side effects of many legal herbicides and their metabolites have not been studies thoroughly.
Studies reveal that a large number of currently legal herbicides and their metabolites can be detected in rivers and streams. However, studies on the potential effects of these contaminants on freshwater integrity and their food webs, as well as quality standards for a large number of herbicides and their metabolites are largely missing. Especially the impact of herbicide-derived metabolites is often neglected. It is largely unknown, how and in which concentrations these groups of herbicides and their metabolites accumulate in algal and macrophytic biomass. In turn, it remains unclear how they further affect the next trophic levels such as macroinvertebrates (MIVs).
In a pilot study we are developing a new and suitable methodological approach for lab experiments, using a flume-setup. We will assess the bioaccumulation potential of glyphosate and two metabolites as well as their effects on the organisms (measuring metabolomics). Metabolomics refers to the identification and quantification of metabolites within a cell, organ, or organism. Environmental metabolomics can be used to study the impacts of environmental stressors in natural populations.
This experimental study is conducted in cooperation with the BOKU Division of Analytical Chemistry and with friendly support of Air Liquide.