Public Health Monitoring of Cyanobacteria and Toxins. This monitoring component provides data to assess potential risks to public health from exposure to cyanobacteria and their toxins occurring in the Klamath River and is based on water column and/or shoreline water sampling within Upper Klamath Lake, Copco and Iron Gate reservoirs, and the Klamath River. A number of species of cyanobacteria have been documented in Upper Klamath Lake, the Klamath River, and reservoirs. The most abundant species include: Aphanizomenon flos-aquae, Microcystis aeruginosa (simply referred to as Microcystis in this document), Dolichospermum (formerly Anabaena) flos-aquae, Gloeotrichia sp., and Oscillatoria sp. Since 2004, Klamath River monitoring has documented elevated levels of toxin-producing cyanobacteria, primarily Microcystis and the toxin microcystin. Microcystins are a class of toxic chemicals produced by some strains of cyanobacteria, including Microcystis, that are released into waters during blooms and when cyanobacterial cells die or cell membranes degrade. Microcystis blooms and microcystin concentrations at elevated levels can present risks to human health and to terrestrial and aquatic species, and can result in impairments to a number of beneficial uses for the waterbody. Microcystins are capable of inducing skin rashes, sore throat, oral blistering, nausea, gastroenteritis, fever, and liver toxicity (WHO 2003; OEHHA 2012).
