Scientists say a toxic bacteria bloom in Lake Erie this past summer was the largest on record, and produced a thick scum so big it could almost cover New York City.
The National Oceanic and Atmospheric Administration says the outbreak surpassed the record-setting bloom in 2011 that stretched from Toledo to Cleveland.
Sandy Bihn is with Lake Erie Waterkeeper Inc.
She says states bordering Lake Erie have to dramatically reduce the amount of phosphorus getting into the lake.
Phosphorus is a nutrient that helps cyanobacteria grow.
Lake Erie is an indicator for all the Great Lakes," says Bihn. "It's kind of the canary in the coal mine. We have to reduce the sources (of phosphorus) and make sure it doesn't happen to the other lakes."
Toxins from a much smaller bloom in 2014 contaminated the tap water for 400,000 people in the Toledo area.