A to Z
Data &
Forms &
News &
Licensing &
Rules &
Public Health
Print this Article   Bookmark and Share
Harmful Algae Blooms
Girl on dock

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. Some partners have decided to reduce or eliminate identification and water sampling of blooms which will affect some of the popular lakes and reservoirs where advisories may have been issued in the past. In these cases, waterbody managers may place permanent signs at well used access points for outreach and educational purposes, and you will no longer see the familiar green and gold OHA signage.

OHA will encourage our partners to continue monitoring and to submit water quality data. Without this data, staff are unable to advise the public about blooms or make recommendations regarding recreational activities.

Since most waterbodies in Oregon are not monitored, OHA 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 partners who can give you the most up-to-date information about local recreation areas, water quality and sampling.

Be aware, be safe and have a great summer season!

Check current water conditions

Check shellfish safety closures

The Oregon Department of Agriculture and Oregon Department of Fish and Wildlife jointly monitor for marine biotoxins and alert recreational harvesters when clams or mussels have been contaminated. 

Check algae resources for drinking water

OHA's Drinking Water Services provides information regarding algae blooms and drinking water.

Check other water related news and Illness information

Water related topics inside OHA and from our partner agencies. 

  • Water News

        Join Our Listserv

    The HABS program has created a listserv to share information with partners, stakeholders and interested public. When a health advisory is issued, an email is sent to subscribers that includes the news release and water sample results (algae species and cell counts). Emails are also sent when an advisory is lifted. Other timely information may be periodically shared as well. To join the list, email us at