Great Lakes: Harmful Algal Blooms

an image of 2017 harmful algal bloom in Lake Erie

A satellite view of a 2017 harmful algal bloom in Lake Erie. Credit: NASA Earth Observatory

Cyanobacteria blooms (blue-green algae) are a frequent occurrence in the Great Lakes, particularly in Lake Erie, Green Bay, and Saginaw Bay. These blooms may cause fish kills and discolored or foul-smelling water, affecting both human and ecosystem health. NOAA provides forecasts of cyanobacteria blooms for Lake Erie from July to October. Some cyanobacteria blooms can grow rapidly and produce toxins that cause harm to animal life and humans, so scientists describe them as harmful algal blooms (HABs).

NOAA Resources

Lake Erie Harmful Algal Bloom Forecast
NOAA’s Harmful Algal Bloom Bulletins are issued twice weekly during blooms of blue-green algae in Lake Erie.

Harmful Algal Bloom Monitoring System: Near Real-Time Imagery
NOAA's National Centers for Coastal Ocean Science developed this site to routinely deliver near real-time products for use in locating, monitoring, and quantifying algal blooms in coastal and lake regions of the U.S. This application delivers a suite of bloom detection products in the form of geographic-based images.

Great Lakes Harmful Algal Blooms and Hypoxia
HAB and hypoxia resources, forecasts, and water quality monitoring from NOAA’s Great Lakes Environmental Research Laboratory.

Frequently Asked Questions
Frequently asked questions about harmful algal blooms and Great Lakes blooms of blue-green algae from NOAA’s Great Lakes Environmental Research Laboratory.

Michigan Sea Grant: Harmful Algal Blooms
Michigan Sea Grant projects, news, products, data, and general information related to harmful algal blooms.

New York Sea Grant: Harmful Algal Blooms
New York Sea Grant projects, news, products, data, and general information related to harmful algal blooms.

Ohio Sea Grant: Harmful Algal Blooms
Ohio Sea Grant projects, news, products, data, and general information related to harmful algal blooms.

Illinois Resources

Harmful Algal Blooms
HAB resources from the Illinois Department of Public Health.

Blue-Green Algae and Harmful Algal Blooms
Resources from the Illinois Environmental Protection Agency.

Indiana Resources

Harmful Algal Blooms
General information, testing sites, and other resources from the Indiana State Department of Health.

Michigan Resources

Harmful ALgal Bloom Resources
HAB resources from Michigan's Department of Environmental Quality.

Minnesota Resources

Harmful ALgal Bloom Resources
HAB resources from Minnesota Sea Grant.

Blue-Green Algae and Harmful Algal Blooms
Frequently asked questions and health information from the Minnesota Pollution Control Agency.

Harmful Algal Blooms
Frequently asked questions, health information, and resources from the Minnesota's Department of Health.

New York Resources

Harmful Algal Bloom Notifications
HAB resources from New York's Department of Environmental Conservation.

Ohio Resources

Lake Erie Harmful Algal Bloom Resources
HAB resources and links from Ohio's Environmental Protection Agency.

Lake Erie Recreational and Beach Monitoring Data
Ohio conducts a monitoring and notification program of selected public and semi-private beaches to test the water quality and notify the public whenever bacteria levels present a potential health risk to those engaged in water activities. BeachGuard provides data on advisories as well as monitoring activity.

Lake Erie Water Monitoring Data
Public water system and other surface water monitoring data from Ohio's Environmental Protection Agency.

Wisconsin Resources

Blue-Green Algae Information
Resources from Wisconsin's Department of Natural Resources.

Blue-Green Algae Health Information
Resources from Wisconsin's Department of Health Services.

Harmful Algal Bloom Toolkit (PDF)
A planning guide for public health and emergency response professionals from Wisconsin's Climate and Health Program.