The Oregon Health Authority updated a recreational use health advisory today for Upper Klamath Lake due to the presence of a cyanobacterial (harmful algae) bloom and cyanotoxins (harmful algae toxins) above recreational guideline values for human exposure. The lake is in Klamath County. The advisory, originally issued July 19, applied to the Eagle Ridge County Park area of Upper Klamath Lake. OHA updates an advisory when new sampling data is received. Sampling data received Aug. 8 showed toxin levels above recreational guideline values in the Howard’s Bay area of Upper Klamath Lake. Satellite imagery shows the entire lake affected by a cyanobacterial bloom. Out of caution, OHA is updating the advisory to apply to the entire lake and will continue to evaluate new information as it becomes available.