The increased population over the past years has resulted in elevated consumption of pharmaceuticals, items of lifestyle and release of industrial effluents containing pollutants (e.g. heavy metals). The improper disposal of these substances has raised concerns in the scientific community regarding their harmful effects on aquatic ecosystems. Conventional approaches for water quality assessment commonly rely on the detection of pollutants in the aquatic environment. However, these approaches are limited by their sensitivity thresholds. On the other hand, effect-based methods present sensitive tools that could support ecotoxicology and risk assessment, utilizing model organisms to examine the effects of pollutants commonly found in the environment. This thesis focuses on the development of a sensitive feeding assay as a phenotypical endpoint for toxicity assessment of emerging pollutants. In addition, it explores the application of phenotypical and physiological endpoints for the investigation of the impact of cigarette filter-derived pollutants on Daphnia magna.