In this comprehensive thesis, the application of effect-based methods already established for surface waters and initial experiments for establishing the stygophilic copepod Eucyclops serrulatus as a species for ecotoxicological testing of groundwater are presented. Through her outstanding scientific work and dedication, Sarah Wohlmann made a significant contribution to the gwTriade project, particularly in the areas of the ecotoxicological bioassay battery and culturing of test organisms.