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Harmful Algae Blooms
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View current advisories.

The Oregon Health Authority (OHA) collects and reviews information on harmful algae blooms, and informs the public through the issuing and lifting of advisories when water sampling data warrants. This information allows people to take protective action to avoid illness before deciding where to recreate. OHA relies on water sampling data provided by our partners. Read more about the water sampling process.

Algae Bloom Awareness: You and Your Pet
Since most waterbodies in Oregon are not monitored,혻OHA staff recommend you become familiar with your surroundings and know the signs of a bloom before you take the plunge.

  • Don't go into water that is foamy, scummy, thick like paint, pea-green, blue-green or brownish red. A good rule of thumb for you and your pet is; When in Doubt, Stay Out!
  • If you believe you or your pet have been exposed to a harmful algae bloom, OHA staff are available to answer health related questions and to receive and document illness reports. We will also provide you with contact information for our partners혻who can give you the혻most up-to-date information about혻local혻recreation혻areas, water quality and sampling.

Oregon region map with advisory locations
The most current information on advisories issued and lifted throughout the season.
A yearly presentation of advisories issued in Oregon since 2005.
Guidelines covers
For lake managers and others who deal with algae blooms
harmful algae bloom
Brochures, posters, fact sheets and journal articles that cover basic information, human health, animal health, fish consumption and environmental concerns.
A list of some agencies involved in responding to harmful algae blooms.