In view of climate change crisis offshore wind energy is becoming increasingly important for the development of renewable energies in Germany. In waters with mainly sandy seabed, such as the North Sea, offshore wind turbines cause a reef effect, as they provide artificial hard substrate as settlement sites for various marine organisms. Since data on load and load flows on artificial structures such as wind turbines affected by biofouling do not exist so far, a seawater wave and current channel is under construction within the EnviSim4Mare project. Knowledge on the biofouling community composition attaching on artificial structures helps to assess its potential effects on surface roughness and consequently the hydrodynamic impacts on those structures. To characterize real fouling communities of the southern North Sea, steel test bodies were installed at a sheltered site (Helgoland's northeast harbor) and an exposed site (Nordergründe sea area) in two habitats (eulittoral, sublittoral). In this bachelor thesis the results of the study year 2021 (May to December) are presented and discussed. Using qualitative and quantitative analyses of the present taxa, three fouling communities could be identified, which were primarily characterized by site and habitat. The biofouling assemblages resemble other communities on artificial hard substrates in the North Sea, and in the case of the Nordergründe site, the communities are similar to communities on wind turbines located in the southern North Sea.