Pesticide risks also in nature reserves

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 (Image: Pixabay CC0)
(Image: Pixabay CC0)

The risks pesticides pose to insects and other small animals in waters in protected areas are almost comparable to those in waters outside protected areas - even if the concentrations of pesticides in waters in protected areas are lower. This was found by scientists at the University of Koblenz-Landau in a recent study.

,,For the first time in Germany, we have evaluated extensive data on the occurrence of pesticides in water bodies and compared nature conservation areas with areas that are not under nature conservation," says Landau ecotoxicologist Jakob Wolfram, lead author of the study. The result: "The risks to aquatic organisms from pesticide exposure are clearly shaped by agricultural land use in the upper reaches of water bodies that are not separately protected." The reason: The headwater area - the complete catchment area of a water body and thus the area that feeds a river - is usually outside the protected areas. Pesticides enter the water there and are washed downstream into the protected areas.

The researchers analyzed more than 3.8 million readings of over 200 pesticides measured by the authorities in the German state of Saxony over the past 20 years. They compared the measured values from the water bodies with the specific threshold values from the official approval for each pesticide in order to identify possible risks for animals and plants. The risk profiles for aquatic plants and small invertebrates (insects and crustaceans) were particularly high, despite the often lower pesticide concentrations in nature reserves. "Overall, our results demonstrate that water bodies in protected areas can be exposed to numerous pesticide risks and thus often fail to achieve an adequate level of protection," Wolfram emphasizes. Better protection of animals and plants must therefore be ensured, especially in protected areas.

As the authors of the study state, the results play an important role in the current discussion about the EU’s agricultural strategy, which aims to reduce the use and risks of pesticides. Environmental scientist Ralf Schulz, co-author of the study, emphasizes: "Our results are highly topical, especially in light of the current calls, especially from Germany, for a softening of the EU’s planned reduction of pesticide use in protected areas."

The study

Wolfram, J., Bub, S., Petschick, L.L., Schemmer, A., Stehle, S., Schulz, R. (2023) Pesticide occurrence in protected surface waters in nature conservation areas of Germany. Science of the Total Environment 858, 160074. https://doi.org/10.1016/j.s­citotenv.2­022.160074