2) 
3) 
4) 
      
  
    
  
   
    
Fig. 9: Eddies in the Baltic, here north of Rügen, illustrated 
by blue green algae, have been shown in the Baltic sea 
for the first time and been verified by ground truth datal?). 7) 
(Black and white rendition of colour coded original). 
3) 
  
13 
Fig. 10: Plastic bag experiments were employed to investigate the 
influence of phosphate on the stimulation of blue green algae 
as well as on the development of heterocysts and the nitrogen 
fixation ability of these algae (diameter of bags 50 cm, length 400 cm).