The Max-Planck Outstation in Schlitz was founded in 1949 and scientists at the station have been collecting data ever since from the nearby stream called Breitenbach in its total length.

Special focus was put on animal and microorganism occurrence and variation as well as chemical and physical parameters, making the stream probably the best-studied stream on earth. In particular the wealth of long-term data going back more than 50 years is unique and makes it a valuable resource for everyone in the world dealing with stream ecology. Already the data influences the discussion of the `good ecological state' reference values and it will be in particular useful to analyze the effect of global warming on the ecology of streams.