Cyanobacterial blooms (see the figure) present health risks worldwide for humans and livestock that drink or use contaminated water, and also represent substantial economic costs to communities due to water treatment, lost tourism and recreation revenue, and declining property values (1). These explosive growths occur in fresh and marine water, and may be increasing globally. One recommendation is that water managers must address the effects of climate change when combating cyanobacterial blooms (2). However, recent studies suggest that controlling nutrients may be more important in increasing aquatic ecosystem resilience to these blooms.Justin D. Brookes and Cayelan C. Care