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Lake Erie affected by algal blooms, Domestic Action Plan aims to achieve a healthier lake

July 30, 2019

Aerial photo of algal bloom. Photo credit: Tom Archer

In June, Governor Whitmer signed an Executive Directive building on goals established in the Michigan Lake Erie Domestic Action Plan to achieve a healthier Lake Erie. The directive established reporting requirements on plan progress.

To provide background on issues affecting Lake Erie, our three-part series will discuss the basics of what algal blooms are; how invasive species are affecting the Lake Erie Watershed; and what local, state, and federal agencies are doing to improve the situation.

But first -- what is happening in Lake Erie? Why is it unhealthy?

Lake Erie, the warmest and shallowest of the Great Lakes, is being impacted by the overgrowth of algae, known as "algal blooms." Some algae are good and necessary for a healthy lake, but too much signals an environmental imbalance. The causes of blooms are complex, but overgrowth of algae is primarily fueled by an excess of nutrients like phosphorus that can come from municipal, industrial, and agricultural sources.

Blooms made up of a specific, blue-green algae type known as cyanobacteria can produce toxins that threaten swimmers and drinking water with stomach illness or neurotoxic symptoms. These blooms can also lead to low oxygen “dead zones,” which can kill fish and other aquatic life.

Mary Anne Evans, a research ecologist with the U. S. Geological Survey Great Lakes Science Center, explains: "Algae is considered harmful when it produces toxins; when it produces compounds that, though not toxic, smell or taste bad; or when it produces so much biomass that it clogs beaches, harbors harmful bacteria, or uses up oxygen needed by fish and other aquatic life."

Government agencies are working together to solve the problem, but progress will take time. Although phosphorus inputs to the lake are being reduced and managed, there is significant legacy phosphorus on the landscape and already in the lake. Funding through the Great Lakes Restoration Initiative and a combination of regulatory and voluntary measures is helping create solutions.

The effects of invasive species like zebra mussels on Lake Erie will be discussed in Erie Series 2.

Get more information at

Photo Credit: Tom Archer


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