Research has revealed that both bees and fish exposed to agricultural chemicals exhibit significant behavioral changes. A study conducted by scientists from the **Helmholtz Centre for Environmental Research (UFZ)** highlights the impact of plant protection products on non-target organisms, underscoring the need for more comprehensive risk assessments moving forward.
The findings, published on **November 6, 2025**, in the journal **Environment International**, indicate that fungicides, herbicides, and insecticides do not solely affect their intended targets. Instead, they pose risks to vital species such as pollinators and aquatic life. According to **UFZ biologist Prof. Martin von Bergen**, non-target organisms inevitably come into contact with these chemicals, potentially suffering harmful effects.
Impact on Pollinators and Aquatic Species
The research specifically focused on two model organisms: the honeybee (**Apis mellifera**) and the zebrafish (**Danio rerio**). By observing their behaviors after exposure to plant protection products, the team aimed to understand how these chemicals affect the health and activities of these species in their natural environments.
Cassandra Uthoff, a doctoral student and lead author of the study, explained that while many plant protection products do not kill non-target organisms outright, even low concentrations can impair their behavior and health. This can have cascading effects on individual populations and overall biodiversity. Despite some existing behavioral tests, Uthoff noted that they are generally not complex enough nor mandatory for risk assessments.
The UFZ researchers employed a robust research approach to analyze how exposure to these chemicals alters behaviors. They found that honeybees exhibited reduced foraging activity and changes in nectar processing when treated with insecticides. Additionally, exposure to fungicides and herbicides resulted in diminished brood care behaviors, which could hinder colony performance and pollination services.
Behavioral Changes in Zebrafish
The study also assessed the impact of plant protection products on zebrafish embryos using a behavior-based screening method. This method allows for rapid evaluation of neuroactive effects, including alterations in learning and memory. The fish embryos were subjected to varying concentrations of a mixture of insecticide, herbicide, and fungicide, reflecting levels found in small streams in Germany.
Results showed distinct behavioral changes based on the concentration of the mixture. At lower levels, fish embryos displayed behaviors typically associated with herbicide exposure. However, at higher concentrations, these behaviors were suppressed and replaced by those linked to fungicide exposure. Prof. Tamara Tal, another co-head of the study, emphasized that these findings reveal the potential for cumulative risks from mixtures of chemicals, suggesting that regulatory standards should account for these interactions.
The researchers concluded that the ecological impacts of plant protection products may be more extensive than previously understood. They advocate for the integration of more relevant behavioral tests in future risk assessments to better protect non-target organisms and contribute to the preservation of biodiversity in agricultural landscapes.
The implications of this research highlight the urgent need for revisions in chemical regulations governing plant protection products, ensuring that they adequately safeguard both terrestrial and aquatic ecosystems.
Further details on this study can be found in the article by Uthoff et al. in **Environment International**.
