NOAA Develops New Method To Forecast Toxin Risk From Harmful Algal Blooms On Lake Erie

Scientists successfully developed an experimental forecast that can better predict the timing and location of an elevated risk of toxins from harmful algal blooms (HABs) on Lake Erie, thanks to recent research from NOAA and a team of university collaborators.

Harmful algal blooms on Lake Erie produce toxins, called microcystins, that can pose health risks to people and pets and may also require additional treatment from public drinking water systems. Bloom toxicity can vary widely depending on different biological and environmental factors, and cell abundance does not always correlate to bloom toxicity.

NOAA does not yet have an operational HAB toxin risk forecast for Lake Erie, but NOAA Great Lakes Environmental Research Laboratory (GLERL) monitors HAB toxin levels in Lake Erie weekly each summer. The NOAA National Center for Coastal Ocean Science (NCCOS) produces a daily Lake Erie HAB forecast of the algal bloom location and issues a qualitative statement on toxins based on weekly monitoring. What’s been missing is longer range forecast information about the location and timing of the toxin risk.

At this time, NOAA has detected microsystin growing in western Lake Erie, but it is not at a level that would trigger health concerns for people, pets or drinking water.

New forecast woud predict toxin five days in advance
The new experimental toxin risk forecast would extend the Lake Erie HAB Forecast, incorporating the weekly monitoring data into a statistical model that allows for predictions of the levels and locations of microcystin toxins five days out. This will allow communities to know ahead of time when the risk may exceed what is advisable for public health. In addition to the forecast, the method provides a best estimate of current conditions.

“This new experimental forecast will provide precise information to give greater advance notice of where and when there is a high risk of microcystin toxin exposure,” said Mark Rowe, a scientist at NOAA GLERL and co-author of the study in Water Resources Research, detailing this new forecasting ability. “Knowing when and where there is high risk is essential for water treatment managers and recreational users on the lake to plan and prepare. Also, knowing there is low risk in an area expands opportunities for recreational boaters, anglers and others who use the lake for many activities.”

The toxin risk forecast combines information from NOAA NCCOS’ satellite remote sensing products, data from NOAA GLERL’s weekly water quality monitoring program in western Lake Erie, and a numerical model that predicts wind-driven currents in Lake Erie. The researchers assessed the quality of the experimental forecast retrospectively using a database of thousands of measurements of microcystins in Lake Erie covering a ten-year period.

Participating institutions in the research also included Ohio Sea Grant and Stone Laboratory; NOAA’s National Centers for Coastal Ocean Science; University of North Carolina Wilmington’s Center for Marine Science; and the Cooperative Institute for Great Lakes Research (CIGLR).

Justin Chaffin, senior researcher for The Ohio State’s University’s Stone Laboratory, part of the College of the Food, Agricultural, and Environmental Sciences, helped the team curate data for the forecast model, including toxin observations from Stone Lab’s charter boat captain sampling program. In addition, researchers used long-term observations of toxin concentrations from GLERL and CIGLR, Ohio Environmental Protection Agency, University of Toledo, and the U.S. Geological Survey.

“The information contained in this research paper will be invaluable for the future forecasting of microcystins,” said Captain Peg VanVleet, Vice President of the Lake Erie Charter Boat Association.”Charter boat captains were pleased to assist in this study by helping take water samples.”

Before the new toxin forecast is transitioned from research to operations, NOAA will evaluate the experimental forecast and seek feedback from constituents.

Resources:
Media advisory: Lake Erie harmful algal bloom seasonal forecast to be issued June 26, 2025

Lake Erie weekly field sampling data: https://www.glerl.noaa.gov/res/HABs_and_Hypoxia/wle-weekly-current/

Lake Erie HAB forecast products: https://coastalscience.noaa.gov/science-areas/habs/hab-forecasts/lake-erie/

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