Abstract: Subrecent Ostracoda associations have been identified in karstic travertine deposits of the ZamantıRiver. In this study, seven species and three taxa left in open nomenclature (mainly of freshwater origin)were investigated: Limnocythere inopinata, Eucyprinotus rostratus, Psychodromus olivaceus, Scottiapseudobrowniana, Potomocypris fallax, Candona neglecta, Heterocypris barbara, Psychodromus sp.,Trajancypris sp. and Cypridopsis sp. Recent climatic and hydrochemical conditions were alsodetermined in detail in order to provide a picture of the environmental conditions dominating over thefauna (Ostracoda) and flora (Bacillariophyceae/diatomeae, Chlorophyceae/green algae,Cyanophyceae/blue-green algae). The results suggest that spring waters with a high carbon-dioxidecontent support the algale population growth.