Serious algae outbreaks have hit more than 20 states this summer. Organisms are shutting down beaches in Florida, sickening swimmers in Utah and threatening ecosystems in California.
The blooms are a normal part of summer, but the frequency, size and toxicity this year are worse than ever.
And water managers are rattled.
"Everyone's on edge with the cyanobacteria," says Bev Anderson, a scientist with the California Water Resources Control Board.
Emails reporting outbreaks of cyanobacteria — or blue-green algae — fill Anderson's inbox every morning.