The Freshwater Research and Environmental Database is the central data repository for IGB. It is where we store and share environmental data from observations of lakes, rivers, peatlands and other freshwater habitats. In FRED you can find continuous data collected over several decades from our long-term research programme at the lakes Müggelsee, Stechlinsee, Arendsee and the river Spree, as well as environmental data derived from short-term projects in aquatic ecosystems. All data include detailed metadata descriptions in text form to allow reuse of the data. The database can be searched for a range of aspects, such as ecosystem types or abiotic and biotic variables. Data use, where not freely accessible, shall be granted after consulting with the contact person given in the database, and is subject to the IGB Data Policy.