The aim of the project is to obtain as accurate an overview as possible of the ecosystems in the German North Sea and Baltic Sea before the start of intensive human use. This will support the development of a scientific basis for decision-making that will enable the Federal Agency for Nature Conservation and the North Sea and Baltic Sea authorities to identify the need for political action to establish specific marine protected areas, to reintroduce projects in the German North Sea and Baltic Sea and to initiate appropriate measures.

As part of the project "The German North Sea and Baltic Sea over 100 years ago", a "historical baseline" is being developed as a guide for determining the necessary nature conservation measures and areas. As various marine organisms are involved in maintaining stable ecosystems, the relevant marine species are being examined in more detail with regard to their abundance. The research will focus on key species that are already extinct and rare in the North Sea and Baltic Sea, such as some cartilaginous fish (e.g. sharks or rays) and other endangered fish species such as marine mammals, birds and benthic organisms.