GRAND RAPIDS, Mich. (WOOD) — Good news for the Great Lakes region. A new forecast from the National Oceanic and Atmospheric Administration expects the harmful algal bloom that pops up each year on Lake Erie will be smaller than usual.
This year’s bloom is forecast to reach a 3 on the harmful algal bloom (HAB) scale, with the range set between 2 and 4.5. Last year’s bloom peaked at 6.8.
The scale is based on the algal bloom’s total biomass during the 30-day period of the peak of the bloom. Anything over a 5 is considered a severe bloom, and anything over 7 indicates “extensive scum formation.”
The forecast is a welcome sight for communities that rely on Lake Erie. The lake has regularly dealt with severe algal blooms in recent years. The 2011 bloom measured at a 10 and the 2015 bloom measured at a 10.5.
Lake Erie’s harmful algal blooms are made up of cyanobacteria and can produce materials that are toxic to both humans and wildlife. Depending on the location and the severity of the bloom, some communities are forced to close beaches, restrict fishing and take different action to treat drinking water.
“The harmful algal bloom forecast translates the latest science into actionable information for our partners and the public,” NOAA Chief Scientist Sarah Kapnick said in a release. Having accurate, reliable information about this year’s expected bloom will help protect public health and economic activity for communities along Lake Erie.”

Typically, nutrition runoff from farm fertilizer feeds the Lake Erie algal bloom. That will still be there, but tapered spring rains should keep things in check.
“While the spring has been quite dry, (Lake Erie) received a large nutrient load in March, which will produce at least a mild bloom this summer,” Richard Stumpf, NOAA’s lead scientist on the forecast, stated. “However, like recent years, we have a potential of additional nutrient load in July, which could lead to a more moderate bloom.”
This year’s bloom on Lake Erie is expected to start sometime between mid-to-late July. Weather patterns through the late summer will dictate how long the bloom survives and where it will end up.
Algal blooms are not common on the Great Lakes and are usually limited to a few key spots: Lake Erie’s western basin, Green Bay in Lake Michigan and Saginaw Bay in Lake Huron. Cyanobacteria blooms are much more common on inland lakes. There were dozens of confirmed blooms last year. Currently, there are two active blooms on inland lakes in Michigan, including Swan Lake in Allegan County.
State agencies provide public updates through an interactive map that shows where cyanobacteria has been reported and where tests have been conducted.
If you suspect a body of water has a harmful algal bloom, officials at the Michigan Department of Health and Human Services recommend keeping people, pets and livestock away from the water. If you have already been exposed, rinse off as soon as possible.
Breathing in or swallowing cyanotoxins can cause several symptoms, including runny eyes or nose, difficulty breathing, vomiting, diarrhea, weakness, headaches and dizziness. Exposure to cyanobacteria can also cause rashes, blisters or hives. Pets are at an even greater risk to harmful algal blooms, especially dogs.
If you believe you were exposed to a harmful algal bloom and feel sick, MDHHS recommends calling your doctor or poison control at 1-800-222-1222.