Algae Bloom - Blog Posts

Our Eyes in the Sky See Toxic Waters

Warm summer temperatures often lead to dangerous blooms of phytoplankton in lakes, reservoirs and along our coastlines. These toxin-containing aquatic organisms can sicken people and pets, contaminate drinking water, and force closures at boating and swimming sites.

In this image, a severe bloom of toxic blue-green algae is spreading across the western half of Lake Erie. Taken on July 30, 2019 by the Operational Land Imager on our Landsat 8 satellite, this image shows green patches where the bloom was most dense and where toxicity levels were unsafe for recreational activities. Around the time of this image, the bloom covered about 300 square miles of Lake Erie’s surface, roughly the size of New York City. By August 13, the bloom had doubled to more than 620 square miles. That’s eight times the size of Cleveland. 

The dominant organism—a Microcystis cyanobacteria—produces the toxin microcystin, can cause liver damage, numbness, dizziness, and vomiting. On July 29, 2019, the National Oceanic Atmospheric Administration (NOAA) reported unsafe toxin concentrations in Lake Erie and have since advised people (and their pets) to stay away from areas where scum is forming on the water surface.

You can stay informed about harmful algal blooms using a new mobile app that will send you alerts on potentially harmful algal blooms in your area. Called CyAN, it's based on NASA satellite data of the color changes in lakes and other bodies of water. It serves as our eye-in-the-sky early warning system, alerting the public and local officials to when dangerous waters may be in bloom.

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