Hypoxia Early Warning System

Lake Erie’s “dead zone” impacts the lake’s ecosystem and poses challenges for managers of drinking water treatment facilities.

Episodes of low dissolved oxygen, or hypoxia, are common during the summer in the bottom water of the central basin of Lake Erie, a source of drinking water for millions of people in northwest Ohio. The hypoxic area or “dead zone” in Lake Erie can grow as large as 6,000 square miles, or 63% of the lake surface area.

With our partners at NOAA GLERL, CIGLR is at the forefront of monitoring and forecasting hypoxia in the Great Lakes, for the protection of human and ecosystem health. Our hypoxia research activities include:

Coastal Hypoxia Research Program (CHRP)

Hypoxic water is usually discolored, acidic, and may contain iron and manganese, requiring costly treatment to avoid undesirable taste and aesthetic problems when it enters drinking water intakes.

Experimental Lake Erie Hypoxia Forecast. Click image to see animation.

In Lake Erie, it is common for strong gradients in water quality to exist between surface water and bottom water in the summer, when the water column is stratified. Because hypoxia events are typically triggered by changes in weather and hydrodynamics (i.e., lake temperature and circulation), they can occur quickly and leave water intakes to be alternately exposed to surface or bottom water and leave drinking water managers little time to prepare for changes in treatment. Surface water has higher pH, and may have high concentrations of phytoplankton, dissolved organic matter, and potentially algal toxins. In contrast, bottom water may have low pH and low dissolved oxygen. This low-oxygen water may contain iron and manganese, which requires additional treatment to remove.

A research team led by scientists from CIGLR and NOAA GLERL is developing a forecasting system to predict the location and movement of hypoxic water in Lake Erie. This system will give advanced warning when conditions are likely to promote hypoxic water movement into the vicinity of drinking water intakes, providing drinking water managers time to prepare for changes in water quality and implement appropriate treatment processes. The forecast system will be supported by in-lake monitoring sensors to measure oxygen concentrations and give an unprecedented view of the complex lake dynamics that control the development and movement of hypoxic lake bottom water.

About the Project

This 5-year project is in collaboration with the City of Cleveland Division of Water, Purdue University, and U. S. Geological Survey, with guidance from a management advisory group including representatives from Ohio public water systems, Ohio EPA, Great Lakes Observing System (GLOS), and NOAA. The work is supported by a $1.4 million award from the NOAA National Centers for Coastal and Ocean Science (NCCOS) Coastal Hypoxia Research Program (CHRP).

2019 Lake Erie CSMI

Monitoring and experimental activities were expanded to further advance the development of the hypoxia model and to better predict when hypoxic water will pose a threat to drinking water intakes. One of the most pressing needs for water intake managers is to better understand the factors controlling the distribution of the naturally-occurring metal manganese (Mn), which is released from sediments in Lake Erie during hypoxia and can accumulate in the water. Results from these experiments have improved our understanding of how hypoxia impacts the accumulation of the heavy metal Mn and the limiting nutrient phosphorus (P). Our experiments and instrument deployments gave remarkably similar estimates of the lag time between the onset of anoxia (water depleted of dissolved oxygen, a more severe condition of hypoxia) and release of P. The high-resolution dissolved oxygen data from the Coastal Hypoxia Research Program project show that the onset of anoxia in the central basin is highly variable among stations and years. Combined with the new information on P release, the research team will show that previous estimates of internal loading of P to Lake Erie are highly uncertain and likely overestimate the total flux by up to 50%. Separately, our findings on Mn dynamics fill a major gap in hypoxia research in Lake Erie. Mn-laden hypoxic water is a major challenge for water treatment facilities and our results could be used to inform new ways to predict when and where those treatment facilities are likely to experience high Mn conditions.

Incorporating Human Dimensions

To meet the needs of coastal communities, public health officials, and local water quality managers and decision-makers, the research team includes social scientists that are addressing the human dimensions of hypoxia forecasting in the Great Lakes. This team is co-designing an experimental hypoxia forecast with public water system professionals to better understand how hypoxia affects public water systems, and to develop a product that meets their information needs as they seek to ensure the delivery of high quality drinking water. 

Learn more about our hypoxia focused stakeholder workshops and events by following this link.

Stay up-to-date on the most recent news and scientific media generated from our Hypoxia Research here:

Products & Resources




Anderson, H.S., T.H. Johengen, C.M. Godwin, H.Purcell, P.J. Alsip, S.A. Ruberg and L.A. Mason. 2021. Continuous In Situ Nutrient Analyzers Pinpoint the Onset and Rate of Internal P Loading under Anoxia in Lake Erie’s Central Basin. Environmental, Science, and Technology: Water. (DOI:10.1021/acsestwater.0c00138). [Altmetric Score]

Biddanda, B.A., A.D. Weinke, S.T. Kendall, L.C. Gereaux, T.M. Holcomb, M.J. Snider, D.K. Dila, S.A. Long, C. VandenBerg, K. Knapp, D.J. Koopmans, K. Thompson, J.H. Vail, M.E. Ogdahl, Q. Liu, T.H. Johengen, E.J. Anderson and S.A. Ruberg. 2017. Chronicles of hypoxia: Time-series buoy observations reveal annually recurring seasonal basin-wide hypoxia in Muskegon Lake – A Great Lakes estuary. Journal of Great Lakes Research. (DOI:10.1016/j.jglr.2017.12.008). [Altmetric Score]

Godwin, C.M.; J.R. Zehnpfennig and D.R. Learman. 2020. Biotic and abiotic mechanisms of manganese (II) oxidation in Lake Erie. Frontiers in Environmental Science. (DOI:10.3389/fenvs.2020.00057). [Altmetric Score]

Liu, Q., E.J. Anderson, Y. Zhang, A.D. Weinke, K.L. Knapp and B.A. Biddanda. 2018. Modeling reveals the role of coastal upwelling and hydrologic inputs on biologically distinct water exchanges in a Great Lakes estuary. Estuarine, Coastal and Shelf Science. (DOI: 10.1016/j.ecss.2018.05.014). [Altmetric Score]

Rowe, M.D., E.J. Anderson, D. Beletsky, C.A. Stow, S.D. Moegling, J.D. Chaffin, J.C. May, P.D. Collingsworth, A. Jabbari and J.D. Ackerman. 2019. Coastal Upwelling Influences Hypoxia Spatial Patterns and Nearshore Dynamics in Lake Erie. JGR Oceans. (DOI:10.1029/2019JC015192). [Altmetric Score]

Rowe, M.D., E.J. Anderson, H.A. Vanderploeg, S.A. Pothoven, A.K. Elgin, J. Wang and F. Yousef. 2017. Influence of invasive quagga mussels, phosphorus loads, and climate on spatial and temporal patterns of productivity in Lake Michigan: A biophysical modeling study. Limnology and Oceanography. (DOI:10.1002/lno.10595). [Altmetric Score]

Rucinski, D.K., J.V. DePinto, D. Scavia and D. Beletsky. 2014. Modeling Lake Erie’s hypoxia response to nutrient loads and physical variability. Journal of Great Lakes Research. 40(Supplement 3):151-161. (DOI:10.1016/j.jglr.2014.02.003). 

Stone, J.P.; K.L. Pangle; S.A. Pothoven; H.A. Vanderploeg; S.B. Brandt; T.O. Hook; T.H. Johengen and S.A. Ludsin. 2020. Hypoxia’s impact on pelagic fish populations in Lake Erie: A tale of two planktivores. Canadian Journal of Fisheries and Aquatic Sciences. (DOI:10.1139/cjfas-2019-0265). [Altmetric Score]

Stow, C.A., Y. Cha, L.T. Johnson, R. Confesor and R.P. Richards. 2015. Long-term and seasonal trend decomposition of Maumee River nutrient inputs to western Lake Erie. Environmental Science & Technology. 49:3392-3400. (DOI:10.1021/es5062648). [Altmetric Score]

Weinke, A.D. and B.A. Biddanda. 2017. From Bacteria to Fish: Ecological Consequences of Seasonal Hypoxia in a Great Lakes Estuary. Ecosystems. (DOI:10.1007/s10021-017-0160-x). [Altmetric Score]

Zhang, H., L. Boegman, D. Scavia and D.A. Culver. 2016. Spatial distributions of external and internal phosphorus loads in Lake Erie and their impacts on phytoplankton. Journal of Great Lakes Research. 42(6):1212-1227. (DOI:10.1016/j.jglr.2016.09.005). [Altmetric Score]

Zhou, Y., A.M. Michalak, D. Beletsky, Y.R. Rao and R.P. Richards. 2015. Record-breaking Lake Erie hypoxia during 2012 drought. Environmental Science & Technology. 49(2):800-807. (DOI:10.1021/es503981n). [Altmetric Score]

Research Themes


Hypoxia Photo Gallery
Video Library

Biogeochemistry Breakdown: The Story Of Hypoxia. Learn more about this phenomenon by watching CIGLR’s first animated, educational video about hypoxia.

Video Library

NOAA GLERL’s Dr. Mark Rowe looks at Lake Erie hypoxia from a different point of view as he presents at the Great Lakes Seminar Series.

Video Library

A Lake Erie upwelling event brought hypoxic water to drinking water intakes along the Ohio shoreline of Lake Erie on September 3, 2016. The animation shows a cross sectional view of Lake Erie from the shoreline near Cleveland to the location of the “Dead Zone” buoy 15 miles north of Cleveland for two weeks surrounding the upwelling. Temperature and dissolved oxygen from an experimental forecast model are shown on the color scale. The north-south component of currents in the lake are shown by the arrows.