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Oregon Health Authority

Cyanobacteria Season

As spring and summer bring warme temperatures, keep and eye out for cyanobacteria harmful algae blooms (CyanoHABs) in Oregon's lakes, rivers, and reservoirs. 

When lab tests confirm cyanotoxins at levels above OHA safety limits, OHA issues recreational health advisories. These advisories help peole make safe choices and avoid affected water to prevent illness. 

We share advisories through press releases, media, email, social media, hotline messages, and this website. Sign up for email alterts to stay informed


Symptoms

Exposure to cyanobacteria and cyanotoxins can cause serious health problems including:

  • Skin rash
  • Diarrhea
  • Cramps
  • Vomiting
  • Numbness
  • Dizziness or fainting

Children, people with weakened immune systems, and pets are most vulnerable to illness.


Pets Are at Risk, Too

Dogs are especially vulnerable to cyanotoxins because of their size and activity level. Sadly, there have been reports of dog deaths from drinking affected waters. 


After several dog deaths along the South Umpqua and mainstem Upmqua Rivers, OHA launched an outreach effort to raise awareness. This event helped pet owners take extra stesps to keep their pets safe. 


When to Avoid Water Contact

Most of Oregon's fresh waters aren't regularly monitored, so you may not always get warnings about CyanoHABs and their toxins. Use the information on this website to recognize blooms and stay safe while enjoying Oregon's waters. 


Avoid water that smells bad or looks foamy, scummy, thick like paint, or is pea-green, blue-green, or brownish red. When in doubt, stay out!