Exerpt from a Daily Standard article by Nancy Allen:


Blue-green algae toxin levels recorded in recent weeks were the highest they've been all year, and much of the Celina shoreline was coated with slimy growth on Tuesday.
Ohio EPA spokeswoman Dina Pierce said toxin levels may have doubled in October due to algae dying off as temperatures dropped.
"Blue-green algae tends to produce and release toxins as it dies off," she said. "Cooler weather causing a mass die-off can lead to higher toxin levels."
The highest algae toxin reading this year of 83.2 parts per billion was recorded in mid-October. Typically, the worst months for blooms are August and September, when temperatures are hot and humid. The high readings in August and September were 50 ppb and 40.2 ppb, respectively. Monthly toxin averages this year were double or more compared to 2011.
Why is the algae blooming in November? It's likely the weather.