Harmful Algal Blooms


Building a harmful algal bloom early warning system A harmful algal bloom in Lake Erieenvironmental sample processor going underwater

In Lake Erie, harmful algal blooms (HABs) typically begin as nutrient-rich water from the Maumee River drains into the warm, shallow western part of the lake.

This warm, nutrient-rich water is perfect for the growth of a type of blue-green algae that creates a toxin called microcystin. In 2014, such a bloom caused the microcystin levels in Toledo tap water to exceed what is recommended by the World Health Organization, triggering a two-day “Do Not Drink” advisory.

Thanks to a grant through the federal Ocean Technology Transition project, GLOS is partnering with NOAA, LimnoTech, Ohio Sea Grant, and Cleveland Water Alliance to build an early warning system (EWS) that will help to address what is increasingly becoming a regional health and safety concern.

2018 was Year One for the project and included defining how an EWS would function. In order to generate localized alerts, the system would have to incorporate data from a variety of sources and include a centralized way to aggregate this data. At the core of the system would be the emerging environmental sample processor (ESP) technology , an existing network of buoys and other sensors throughout the western part of the lake.

With access to data from this network of sensors, the goal is that water managers and decision makers could anticipate outbreaks of harmful algae and react to keep people safe. The EWS will be an evolution of our existing HABs data portal.

Photos: (Left) NOAA Great Lakes Environmental Research Laboratory staffer submerges the ESPniagara during a test deployment in June of 2016. Courtesy of NOAA Great Lakes Environmental Research Laboratory. | (Right) Satellite imagery captured on Aug. 1, 2014 shows the harmful algal bloom that caused a two-day shutdown of Toledo’s municipal water supply. NASA image courtesy Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team at NASA GSFC


Additional partners include University of Toledo, Heidelberg University, Bowling Green University, U.S. Geological Survey Great Lakes Science Center, National Weather Service, Environmental Protection Agency, City of Toledo Drinking Water Treatment Plant, City of Cleveland Drinking Water Treatment Plants, and other Lake Erie drinking water treatment plants.

More On the Environmental Sample Processor 

The ESP, affectionately known as “a lab in a can,” does real, automatic chemical analysis while deployed in the water, reducing the need for researchers to go out in the water to collect samples and return to labs to process them. It gets results faster and more frequently.

NOAA researchers recently began using the technology in Lake Erie, the first freshwater application. Sensors for the system were developed by NOAA National Center for Coastal Ocean Science.

It answers the question: “Is the water toxic?” and, coupled with information about where the water is moving, can help understand water toxicity.

Watch a video about ESP’s in the 2017 field season.

NOAA currently distributes a twice-weekly email bulletin about Microcystis in western Lake Erie.

Have a question? Email us at info@glos.us.


Funding for this project has been provided by the U.S. IOOS Ocean Technology Transition Project. This national project sponsors the transition of emerging marine observing technologies, for which there is an existing operational requirement and a demonstrated commitment to integration and use by the ocean and Great Lakes observing community, to operational mode.

Project Contact:

Becky Pearson, bpearson@glos.us

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HABs Data Portal