Michigan Harmful Algal Blooms (HAB) — NOAA Great Lakes Outlook

The current reading for this indicator updates live on the Michigan Gateway dashboard. The data feed below is fetched from NOAA Great Lakes Environmental Research Lab (GLERL) via the public /api/algal-blooms endpoint.

Harmful algal blooms (HABs) are excessive growths of cyanobacteria (sometimes called blue-green algae) that can produce toxins like microcystin. In Michigan they're most common in western Lake Erie and Saginaw Bay during late summer. The 2014 Toledo water crisis — when microcystin contaminated drinking water for 500,000 people — was caused by a Lake Erie HAB.

• Do not swim, drink, or let pets enter water that looks like spilled paint, has green scum, or smells musty.
• If exposed, rinse skin and eyes with clean water immediately. Watch for nausea, vomiting, or skin rash.
• If your drinking water comes from Lake Erie or Saginaw Bay, follow your water utility's daily advisories.
• Report a suspected bloom to EGLE at AlgaeBloom@Michigan.gov with photos and location.