This studies reconstructs the development of four lakes, based on the analyses of subfossil diatom assemblages, as a part of Multi- proxy analyses in the area of NW Germany. The target was to distinguish anthropogenic and climatic influences. Strong climate signals, as the Medieval Climate Optimum and the Little Ice Age could be determined in the entire area between Bremen, Oldenburg and Bremerhaven (NW Germany). Additionally strong anthropogenic impact related to the enhancing agriculture, especially in the realm of Oldenburg, could be proved. Less intense signals west of the Weser river exist, since the Bronze Age. Nevertheless only one lake is characterized by eutrophication processes, whereas the further waters fulfill the requirements of the Water Frame Work directive.