Lake Erie Harmful Algal Bloom Seasonal Assessment

Provided by NOAA's National Centers for Coastal Ocean Science (NCCOS)

This bulletin provides the 2025 seasonal assessment of the Microcystis cyanobacterial harmful algal bloom (HAB) in western Lake Erie.

Please note, this will be the final bulletin of the 2025 bloom season. We will resume sending out bulletins in spring 2026.

Click here to view more information and links about NOAA's Lake Erie and HAB Forecasting.

Please check Ohio EPA's site on HABs for safety information.

Click here to subscribe to the HAB forecasts and seasonal projections for Lake Erie

Please continue to email questions and comments to hab@noaa.gov.

Sincere thanks,

NCCOS HAB Forecasting Branch

Interpreting the Forecast System:

• Forecast System Guide: For a detailed explanation of the Lake Erie Forecast System, view the Lake Erie HAB Forecast Guide
• FAQ's: For Frequently Asked Questions about cyanobacteria and the forecasts NOAA issues, view the FAQs Page

Health Information:

• For HAB safety information, please visit Ohio EPA
• For current HAB conditions at Lake Erie Beaches, please visit Ohio DOH BeachGuard

Additional HAB monitoring and forecasts:

• NOAA NCCOS HAB Monitoring System
• NOAA NCCOS HAB Forecasting

Copyright © 2025 NOAA/National Center for Coastal Ocean Science, All rights reserved.