Effects of temperature,illumination and cell density on growth and competition of three species of water-bloom cyanobacteria

Abstract

The effects of temperature,illumination and initial algae cell density on growth and competition of Microcystis aeruginosa,Merismopedia minima and Pseudanabaenamucicola were studied by the method of single factor experiment and orthogonal experiment.The results showed that both M.aeruginosa and M.minimacould grow optimally under higher temperature and/or higher illumination.P.mucicola has competitive advantage only under lower temperature and lower illumination.Under the same temperature and illumination conditions,the initial density of algae cells is the key factor for competing the dominant species position.In addition to controlling the input of nutrients and other pollutants,paying attention to the changes of phytoplankton community structure,controlling and reducing the biomass of cyanobacteria before the water blooms may be another effective way to control cyanobacterial blooms in freshwater lakes or reservoirs