Konstantinos Stefanidis’s Ph.D. thesis focused on the effects of eutrophication on the structure and dynamics of aquatic macrophyte communities and the role of aquatic vegetation in affecting multiple ecosystem functions (e.g., maintaining clear water conditions through nutrient retention and providing refuge to large grazers). In parallel, he had the opportunity to participate in the EU project REFRESH and work with a pan-European outdoor mesocosm experiment. The main objective of the experimental research was the investigation of the potential effect of climate change on planktonic communities, nutrient dynamics and ecosystem metabolism of lakes. From 2014 to 2018, he worked at the Department of Water Resources and Environmental Engineering of the NTUA for the European project MARS. Since 2018, he has been working at the Institute of Marine Biological Resources and Inland Waters (IMBRIW) for the National Monitoring Program of Ecological Quality in Rivers and particularly with the hydromorphological assessment of running waters. His research interests include the study of ecological processes in shallow lakes, the use of aquatic macrophytes as ecological indicators in rivers and lakes and the impact of climate change on freshwater ecosystems.