Some species of bluegreen algae can produce toxins harmful to people and animals. Toxins such as anatoxin-a and microcystin can be produced by blooms of bluegreen algae. Anatoxin-a is a potent nerve toxin and chronic exposure to microcystin can cause liver damage.
Harmful algae blooms are most frequently observed in Anderson Lake but have also been seen in Lake Leland and Gibbs Lake. Check our Lake Status page for the most recent observations.
Blooms are most common in summer but can also occur at any time of year. Toxins produced by bluegreen algae may be present during a visible bloom or may persist after a bloom has disappeared. Visible blooms can also be produced by diatoms, green algae or non-toxic bluegreen algae species that are not harmful.
Report a Bloom
If you see a bloom on a Jefferson County Lake, please report it by calling 360-385-9444.