USGS/NPS Water-Quality Partnership

Emerald-green harmful algal blooms have become an all-too-familiar summertime sight in many U.S. lakes and reservoirs. A new study successfully predicts when mixtures of the toxins produced by these blooms in Kabetogama Lake, Voyageurs National Park, will exceed drinking-water guidelines.

Scientists developed a statistical approach (model) to use both readily available measurements, such as wind speed, and laboratory measurements, such as cyanobacteria toxin gene counts, to predict levels of a single toxin and—for the first time—a mixture of toxins. Although the models were developed for Kabetogama Lake, the approach used could be applicable to other lakes or beaches where harmful algal blooms occur.