Although freshwaters cover less than one per cent of the earth’s surface, they are some of the most species-rich habitats on our planet – so far at any rate. After all, rivers and lakes are experiencing a rapid decline in biological diversity. And yet it is still unclear what this loss means for our well-being in the long term. One important objective of our research is therefore to identify measures that enable us to protect the biodiversity of our freshwaters as effectively as possible. We investigate the causes, draw up forecasts relating to changes, and pool our expertise in biodiversity research and in knowledge-based environmental protection. Collaborating with international partners, we also collect global data on biodiversity in freshwaters, creating a unique foundation to ensure their protection.