The Oregon Health Authority issued a health advisory on July 28 for Howard Bay, located in the southwest corner of the lake.
People are advised to avoid areas that look foamy, scummy, thickened, or colored green, blue-green or brownish-red.
Swimming or high-speed water activities where water could be ingested or inhaled is not advised.
Drinking water from Upper Klamath Lake’s Howard Bay is especially dangerous, according to OHA.
The toxins cannot be removed by filtering, boiling, or treating water.
Those who choose to eat fish from the lake should remove all fat, skin and organs before cooking, as the toxins are most likely to collect in those tissues.
Exposure to blue-green algae toxins can produce symptoms including tingling, numbness and dizziness.
It could even lead to more serious conditions that can lead to difficulty breaking.
OHA said the advisory will be lifted when the concern no longer exists.
To find out more about algae blooms in a specific body of water, you can visit http://www.healthoregon.org/hab and select “algae bloom advisories,” or call the Oregon Public Health Division toll-free information line at 877-290-6767.