Using system diagnosis to assess pressures on aquatic systems

Pharmaceuticals are therapeutic agents contaminating aquatic systems and hence included in the Water Framework Directive’s watch list of Contaminants of Emerging Concern. High global consumption of pharmaceuticals has led to their increased occurrence in aquatic systems. As they are designed to be therapeutically active at ng/L to μg/L concentrations, pharmaceuticals can affect non-target organisms in aquatic system exhibiting sub-lethal effects. Sub-lethal effects caused by pharmaceuticals can be direct when there are similarities in the mode of action. Indirect effects triggered by pharmaceuticals can be density-mediated and/or trait-mediated including the once caused by the disruption and/or mimicking of infochemicals involved in chemical communication between organisms.
In this project, we explore the sub-lethal effects of pharmaceuticals on aquatic food web functioning. Firstly, by understanding the impact of sub-lethal concentrations of pharmaceuticals on trophic interactions. Secondly, we assess the significance of these sub-lethal effects on aquatic food web functioning. Therapeutic drugs with high global occurrence, environmental relevance and persistence are used for all the experiments. The observations and findings of this project will inform the water managers about the significance of considering the sub-lethal effects of environmental concentrations of pharmaceuticals on aquatic ecosystems while determining their environmental risk limits.