In a recent publication in Microbial Ecology, research funded by NCCOS illuminates the role of organic phosphorus in causing blooms of the toxic Microcystis aeruginosa. Toxic cyanobacteria (once called blue-green algae) such as Microcystis have become a serious threat to human health in many freshwater ecosystems, including the Great Lakes.

Previous research has focused on the role of dissolved inorganic phosphorus, the most common form, as the cause of cyanobacterial blooms and has ignored the less abundant organic phosphorus. Funded research at the State University of New York at Stony Brook has determined that as available inorganic phosphorus is used up in the spring and early summer, the normally unavailable organic phosphorus becomes more important to cyanobacteria. To utilize the normally unavailable organic form of phosphorus, Microcystis turns on special genes allowing it to bloom under conditions unfavorable to other phytoplankton.

This study shows the need to manage all forms of the polluting nutrient phosphorus in freshwaters to control toxic Microcystis blooms.