PORTLAND, Ore. — Oregon Health Authority has lifted the recreational use health advisory issued for all areas of Upper Klamath Lake in Klamath County. OHA issued the advisory Nov. 4, 2020.
Water monitoring has confirmed that the level of cyanotoxins in Upper Klamath Lake is below recreational guideline values for people. However, officials advise recreational visitors to be alert to signs of cyanobacteria blooms. This is because blooms can develop and disappear on any water body at any time when bloom conditions are favorable. Only a fraction of waterbodies in Oregon are monitored for blooms and toxins.
People and especially small children and pets should avoid recreating in areas where the water is foamy, scummy, thick like paint, pea-green, blue-green or brownish-red in color, if a thick mat of blue-green algae is visible in the water, or bright green cells are suspended in the water. If you see these signs, avoid activities that cause you to swallow water or inhale droplets, such as swimming or high-speed water activities.
Cyanotoxins can still exist in clear water. When a bloom dies, toxins released may reach into clear water around the bloom. Blooms can be pushed into other areas, leaving behind the toxins released. There also are species of cyanobacteria that anchor themselves at the bottom of a water body, live in the sediment, or grow on aquatic plants and release toxins into clear water near the surface.
For health information or to report an illness, contact OHA at 971-673-0482.