Figure 7. Representative microscopic observations (X200, brightfield) of dominant cyanobacterial genera in the mesocosm experiment conducted during 2013.
Samples were collected towards at the end of the experiment, 31 July 2013. (A) Control (no nutrient addition). (B) N-only addition. (C) P-only addition. (D) N+P addition. Note the overall dominance by Microcystis spp. colonies. However, an increase in number of filaments of the N2 fixing genus Anabaena was observed in the phosphorus and phosphorus and nitrogen treatments. No significant N2 fixation was observed in either of these treatments however. Biomass-wise, Microcystis spp. clearly dominated the cyanobacterial community in all treatments.