Effects of Electromagnetic Treatment on Growth and Photosynthesis of Three Common Freshwater Phytoplankton Species

A study was done using three common freshwater phytoplankton species of Chlorella vulgaris, Microcystis aeruginosa, and Cyclotella pseudostelligera, where the effects of two low power electromagnetic fields (EMF) on phytoplankton growth and photosynthesis were assessed. Growth was quantified by direct cell count and photosynthetic rates were measured as oxygen production with an oxygen probe. Results showed that maximum densities of C. vulgaris and M. aeruginosa were increased by application of an EMF, as was the growth rate of M. aeruginosa, and there were also differences in respiration rates. C. pseudostelligera, in contrast, had lower growth rates and maximum cell densities when exposed to EMF. These results may be attributed to differences in cell structures, particularly differences in the composition of cell membranes, and charge environments. Future studies should focus on mixed cultures as well as examining how specific cellular responses such as nutrient uptake may differ in response to EMF.