New laboratory research shows that when viruses attack a species that forms toxic algal blooms, those thick, blue-green slicks that choke waterways and that threaten ecosystems, drinking water, and public health, what results might be even worse than before the infection. The finding questions the long-held theory among scientists that the viruses help regulate the negative effects of these blooms.  

A team of environmental microbiologists led by Dr. Jozef Nissimov, a professor at the University of Waterloo, has shown for the first time experimentally that when viruses infect and kill Microcystis aeruginosa, a common species responsible for harmful algal blooms (HABs), they cause the release of high levels of the toxin microcystin-LR into the water from the infected cells.