Effects of a realistic pesticide spraying sequence for apple crop on stream communities in mesocosms: negligible or notable?

Environmental Sciences Europe

Research

Tobias Frische¹  Sabine Duquesne²  Michael Feibicke³  Silvia Mohr³  Stefan Meinecke³  René Sahm⁴ 

[1] Section II 2.6 Soil Protection Measures, German Environment Agency, Woerlitzer Platz 1, 06844, Dessau-Rosslau, Germany;Section IV 1.3 Plant Protection Products, German Environment Agency, Woerlitzer Platz 1, 06844, Dessau-Rosslau, Germany;Section IV 2.5 Trace Analysis, Artificial Ponds and Streams, German Environment Agency, Schichauweg 58, 12307, Berlin, Germany;Section IV 2.5 Trace Analysis, Artificial Ponds and Streams, German Environment Agency, Schichauweg 58, 12307, Berlin, Germany;Department Freshwater Ecology in Landscape Planning, University of Kassel, Gottschalkstrasse 26a, 34127, Kassel, Germany;

关键词: Regulatory acceptable concentration (RAC);    Benthic macroinvertebrates;    Periphyton;    Macrophytes;    Pesticides;    Toxic effects;   

DOI  :  10.1186/s12302-023-00739-y

 received in 2023-01-20, accepted in 2023-04-23,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundSeveral large-scale studies revealed impacts and risks for aquatic communities of small rural lakes and streams due to pesticides in agricultural landscapes. It appears that pesticide risk assessment based on single products does not offer sufficient protection for non-target organisms, which are exposed repeatedly to pesticide mixtures in the environment. Therefore, a comprehensive stream mesocosm study was conducted in order to investigate the potential effects of a realistic spraying sequence for conventional orchard farmed apples on a stream community using pesticides at their regulatory acceptable concentrations (RACs). Eight 74-m-long stream mesocosms were established with water, sand, sediment, macrophytes, plankton and benthic macroinvertebrates. In total, nine fungicidal, four herbicidal and four insecticidal pesticides were applied in four of the eight stream mesocosms on 19 spraying event days in the period from April to July while the remaining four stream mesocosms served as controls. The community composition, the abundance of benthos, periphyton and macrophytes, the emergence of insects, physico-chemical water parameters, and drift measurements of aquatic invertebrates were measured.ResultsThe pesticide spraying sequence induced significant effects on invertebrates, periphyton, and macrophytes as well as on the water ion composition especially in the second half of the experiment. It was not possible to relate the observed effects on the community to specific pesticides applied at certain time points and their associated toxic pressure using the toxic unit approach. The most striking result was the statistically significant increase in variation of population response parameters of some taxa in the treated mesocosms compared to the controls. This inter-individual variation can be seen as a general disturbance measure for the ecosystem.ConclusionsThe pesticide spraying sequence simulated by using RAC values had notable effects on the aquatic stream community in the conducted mesocosm study. The results indicate that the current risk assessment for pesticides may not ensure a sufficient level of protection to the field communities facing multiple pesticide entries due to spraying sequences and other combined stress. Hence, there is still room for improvement regarding the prospective risk assessment of pesticides to further reduce negative effects on the environment.

【 授权许可】

CC BY   
© The Author(s) 2023

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