Ecotoxicological studies traditionally focus on exposing organisms to a single stressor. However, rarely does data from such studies provide the predictive power to understand the outcome of combined stressors, which can together exacerbate, prevent or reduce the effects of the others. For example, natural environments are characterized by dynamic and complex physico-chemical parameters, which can combine with pollutants and affect residing organisms in unpredictable ways. To improve our understanding on the effects of foreign chemicals in aquatic environments, we introduce key technological advances to the field of ecotoxicology and employ them in a range of cutting-edge experiments. Key to these experiments is the conjoint examination of toxicological impacts on cellular physiologies under laboratory-engineered environments. Our main hypothesis is that perturbations in environmental parameters, like those expected to intensify due to climate change (e.g. temperature), will affect the systemic toxicity of chemicals by eliciting changes in the physiology of organisms and/or by altering the toxicity of the chemical itself. We test these hypotheses on aquatic bioindicator species, e.g. bacteria, microalgae and fish-embryos, within ‘ecotoxicology-on-a-chip’ approaches which enable us to quantitatively assess the physiological state of these organisms under combinations of chemical and environmental perturbations. The data and methods developed in this project will significantly advance our experimental abilities to test collective stress-effects and improve the prediction of chemical risks in aquatic habitats under forecasted climate change scenarios.