This lagoon is situated on the Baltic Sea in Pommerania in North-East Germany. They are called ‘bodden’. These bodden are enclosed by long narrow spits of land and islands, leaving only narrow passages to the open sea or to adjacent lagoons. Their banks are generally overgrown with reeds. Freshwater flows in from the mainland and at the same time there is a daily fresh inflow of salt seawater with the tides, fluctuating with the wind-direction and wind-strength. All these factors lead to fluctuating salt gradients and special ecosystems in a dynamic area, where sudden changes may occur, for instance when old passages to the sea are blocked by storm surges or new ones come about.