is an Aquatic Microbial Ecologist currently working as senior scientist at the Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB) and as a Professor for Biodiversity and Microbial Ecology at Potsdam University (UP), Germany, where he serves in a good number of scientific and managerial positions. His main interests are with aquatic biodiversity, environmental pollution and global change, aquatic microbial ecology and functioning of ecosystems.