This year, Iowa’s state-owned beaches set records for the number of health advisories issued for high microcystin levels. Microcystin is a liver toxin that can form from cyanobacteria, commonly called blue-green algae.
The algae can form large blooms during the summer months, filling lakes with green or blue sludge. Only some strains of cyanobacteria produce the toxin and scientist say it is hard to predict when the toxin will be produced.