In the Baltic Sea, the ecological conditions are different from the ones in the North Sea: it is the biggest brackish water area, which has evolved over the relatively short period of the past 12,000 years. While the salinity in the central Baltic Sea ranges between 15 and 25 per mill, it can be as low as 2 per mill in the north-eastern area. In contrast to the North Sea, the tides only change by centimetres; any noteworthy changes in the water level mainly occur due to the influence of the wind, and create mud flats.
In the past, it was not legally possible to establish nature reserves or surfaces appropriate for wind energy in the EEZ. This has changed with the entry into force of the amendment of the Federal Nature Conservation Act (BNatSchG) adopted by the German Bundestag. The EEZ sea areas were studied in order to identify the areas that are worth protecting. Charts with the proposed areas and with information on the dispersion of such animals as migratory birds and porpoises, or habitats in the North Sea and in the Baltic Sea are published on the Internet by the German Federal Office for Nature Conservation.
There is still insufficient knowledge that would allow us to assess the overall impact of offshore wind turbines and of the construction and operation of the corresponding submarine cables on the marine environment. Ultimately, the impact that offshore wind farms and their connection to the extra high voltage grid have on the marine environment and nature can only be assessed reliably when the first larger projects have been realised.