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