Effects of antimicrobial compounds on aquatic macroinvertebrates via bottom-up regulation

Project leaders: Prof. Dr. Ralf Schulz, Ass.-Prof. Dr. Mirco Bundschuh

Leaf material from the riparian vegetation represents a large portion of the energy budget of small, low-order streams. During the breakdown of this material, microorganisms (i.e., bacteria and fungi) transform leaves chemically and physically (i.e., conditioning), thereby increasing their palatability and nutritional value for leaf-shredding macroinvertebrates. However, this fundamental step in detritus processing is determined by interactions among leaf-associated microorganisms (both between bacteria and fungi as well as among fungal species), which can be affected by antimicrobial substances such as antibiotics and fungicides. The main objective of AQUA-REG is thus to assess potential implications of antimicrobial substances with different target organisms (bacteria vs fungi) in the conditioning of leaf material and the effect propagation to leaf-shredding aquatic invertebrates (i.e., bottom-up directed effects). The main focus will be on the physiological and population responses of shredders if fed on leaf material conditioned in presence of different antimicrobials. Moreover, molecular biological methods will be utilized and refined to more reliably assess the composition of leaf-associated microbial communities. This approach ultimately facilitates a mechanistic understanding of the bottom-up effects of antimicrobials in a heterotrophic food web.


Jochen P. Zubrod

Patrick Baudy

Marco Konschak


Bottom-up effects (via shifts in leaf-associated microbial communities) of antimicrobials will be assessed at different levels of ecological complexity

Top-view of an experimental unit to assess the food choice of leaf-shredding invertebrates


Assessment of population-level effects using artificial streams