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Algal slurry at the top of a stagnant pond forming swirl and bloom patterns

The Wisconsin Department of Health Services, Division of Public Health (DPH) collects information about human and animal illness resulting from exposure to blue-green algae.

Tracking illness information will help DPH measure the problem of blue-green algae in our lakes and rivers.

If you get sick after swimming in a Wisconsin lake or river, please report possible algae-related illness.

This program does not provide medical treatment, so if you are experiencing severe symptoms seek medical attention immediately.

When in doubt, stay out!

Report blue-green algae-related illness

Members of the general public and veterinarians should call 608-266-1120 or complete the online form Harmful Algae Bloom (HAB) Illness or Sighting Survey, F-02152 (web survey) to report any blue-green algae blooms and related human or animal illnesses.

Questions? Call 608-266-1120 or email us at

Last revised February 23, 2024