Without microorganisms, our ecosystems would not function properly: fungi “predigest” food, parasites keep blue-green algae in check, and water fleas play an important role in aquatic food web dynamics and structure. At IGB, many researchers are working on different microorganisms, studying both the ecology of these organisms and the extent to which they are threatened by climate change and other human-induced changes. While the findings are fascinating, they are also a stark reminder that the diversity of life in our waters is under threat - even the microbes.