Great Lakes
NOAA aims to engage and inform interested and impacted communities in the Great Lakes. With limited research and robust monitoring on acidification in the Great Lakes, researchers establish monitoring networks, study biological sensitivities and develop predictive models.
Understanding and addressing acidification impacts
The Great Lakes are the largest freshwater system on Earth, holding 95% of the U.S.’ and 20% of the world’s surface freshwater. The Great Lakes Region includes Lake Superior, Michigan, Huron, Erie, and Ontario. Acidification in the Great Lakes Region is predicted to occur at a rate similar to the oceans. In the Great Lakes, acidity is also influenced seasonally and spatially by local primary productivity and historical impacts from acid deposition associated with poor air quality. This region supports culturally and economically significant world class fisheries producing $7B in annual economic value, and recreational tourism that create significant income for the regional and U.S. economy. Compared to ocean and marine coastal acidification, little past effort has been invested in monitoring or understanding potential effects of acidification in the Great Lakes and impacts to surrounding communities.
Tracking progress of acidification research in the Great Lakes

The research goals in the Great Lakes Region are to:
- Establish a monitoring network that is designed to detect trends in pH and carbonate saturation states, taking into account the considerable spatial and temporal variability
- Conduct research to understand the sensitivity of plankton, fish, invasive mussels and other biota to changes in pH and carbonate saturation states, including early life stages
- Develop physical/biogeochemical and food-web models that can project the impacts of changing pH and carbonate saturation states on important ecological endpoints, including plankton community composition and productivity, nuisance and harmful algae, invasive mussels, and fish
- Engage people and industries in the process of evaluating impacts in order to identify research topics, communicate research findings, and develop mitigation and adaptation strategies.
The following charts represent the mid-point progress in implementing research actions that focus on the Great Lakes Region according to the NOAA Ocean, Coastal, and Great Lakes Acidification Research Plan.
NOAA invests in research and activities toward meeting goals that improve our ability to understand and predict environmental change, species and ecosystem to response to changing water chemistry, and the human impacts of these changes. The report card below summarizes progress over the past five years toward meeting these goals for the Great Lakes Region, measured by the number of major actions toward meeting this goal: good progress (4+ actions), some progress (1-3 actions) and no known progress.
Good overall progress
Some progress
No known progress
Environmental Change
There are two environmental change actions: one has good overall progress and one has made some progress.
There is currently no existing long-term carbonate chemistry monitoring program in the Great Lakes region, representing a major observing and knowledge gap on how acidification has evolved in the past and continues to progress into the future. Building out an observing network will be critical to understanding the drivers of acidification and predicting future trends in pH.
Biological Sensisitivity
There are eight biological sensitivity actions: six have made some progress and two have no known progress.
Researching biological sensitivity in the Great Lakes will focus on how higher carbon dioxide and temperature impact harmful algal blooms and the sensitivity of various species to changes in water chemistry, particularly early life stages. Scientists will also incorporate carbonate chemistry into models to predict the ecosystem effects.
Human Dimensions
There are two human dimension actions: one has made some progress and one has no known progress.
Using scientific research and public trust and awareness of NOAA’s efforts, engaging with impacted communities and the public will help develop effective acidification adaptation and mitigation strategies that support livelihoods and economies.
Featured Research Projects
Biological Sensitivity
OAP Funded Projects

- PI(s): Noel Urban, Michigan Technological University
- Fiscal Year Funded: 2025, 2026, 2027
- Grant Award # NA24OARX017G0022-T1-01

- PI(s): Reagan Errera
- Fiscal Year Funded: 2024, 2025, 2026
Latest Publications
- Paul McElhany, D. Shallin Busch
- Frontiers in Marine Science
- November 14, 2024
- Elise M. B. Olson, Jasmin G. John, John P. Dunne, Charles Stock, Elizabeth J. Drenkard, Adrienne J. Sutton
- Earth and Space Science
- July 22, 2024
- Adrienne J. Sutton and Christopher L. Sabine
- Oceanography
- October 30, 2023
PMEL air-sea CO2 and ocean acidification time series funded by GOMO and OAP. PMEL contribution 5476
Get involved with ocean acidification
The NOAA Ocean Acidification Program exists to meet the ocean acidification research and monitoring needs of the U.S. See how you can get involved to serve your community and participate in cutting-edge research and education and outreach.