Research conducted by scientists from the Helmholtz Centre for Environmental Research (UFZ) has uncovered significant behavioral changes in bees and fish exposed to common crop protection chemicals. The findings, published in the journal Environment International on November 6, 2025, highlight the potential risks posed by fungicides, herbicides, and insecticides to non-target organisms in both terrestrial and aquatic ecosystems.
The study addresses the unintended consequences of agricultural practices, emphasizing that while plant protection products are designed to safeguard crops from pests and diseases, they also pose threats to species such as pollinators and fish. According to Prof. Martin von Bergen, one of the principal investigators, these chemicals can reach high concentrations in the environment shortly after application, affecting wildlife far beyond the targeted areas.
To assess the impact of these chemicals, the research team selected honeybees (Apis mellifera) as a model for terrestrial organisms and zebrafish (Danio rerio) for aquatic studies. The focus was on behavioral changes resulting from exposure to these substances at concentrations typically found in their habitats.
Impact on Pollinators and Aquatic Life
The study revealed that exposure to insecticides significantly reduced foraging behavior in honeybees and altered their nectar processing activities. Furthermore, exposure to fungicides and herbicides led to decreased brood care behavior among the bees. According to Cassandra Uthoff, a doctoral student and lead author of the study, such alterations in behavior can jeopardize colony success and reduce pollination services, which are vital for ecosystem health.
In the aquatic environment, researchers employed a behavior-based screening method using zebrafish embryos to evaluate neuroactivity effects from the chemicals. The results showed clear behavioral changes in the embryos when exposed to a mixture of insecticide, herbicide, and fungicide, reflecting the cumulative impact of these substances. Low concentrations triggered behaviors typical of herbicide exposure, while higher concentrations prompted responses consistent with fungicide exposure.
Prof. Tamara Tal, co-head of the study, emphasized the importance of understanding how mixtures of chemicals can alter animal behavior. “These findings support the notion that environmental regulations should account for cumulative risks to better protect wildlife,” she stated.
Recommendations for Risk Assessment
The findings from this research suggest that existing risk assessment frameworks for plant protection products may need to be updated to include more complex behavioral tests. Current assessments often overlook the subtle yet significant impacts that low concentrations of chemicals can have on non-target organisms.
The UFZ research team advocates for integrating these behavioral assessments into regulatory processes to identify critical substances that could harm biodiversity. Their work indicates that the ecological effects of plant protection products may extend beyond previous assumptions, underscoring the need for more comprehensive evaluations.
As the research community continues to explore the implications of chemical exposure on wildlife, the UFZ study serves as a call to action for policymakers. By prioritizing the health of non-target species, there is potential to enhance biodiversity in agricultural landscapes and promote sustainable farming practices.
The implications of this study resonate widely, highlighting the urgent need for further research and legislative action to safeguard ecosystems affected by agricultural chemicals. The potential risks associated with plant protection products demand heightened attention to ensure a balance between agricultural productivity and environmental health.
