Reduced growth of the cyanobacterium microcystis in an artificially mixed lake and reservoir

The effectiveness of artificial deep mixing to control Microcystis was tested in the highly eutrophic Nieuwe Meer lake by comparing its prevalence in years when no mixing occurred with those when it was carried out. The mixing reduced the average number of Microcystis colonies while apparently increasing non-buoyant algae, green algae and diatoms, probably through reduced sedimentation losses. Where Microcystis could avoid the mixing regime it received more light and grew strongly. The fact that colonies synthesizing carbohydrates were denser than those experiencing restricted light was a means of determining mixing efficiency.