Health Advisory Lifted – New water monitoring has confirmed that the level of blue-green algae toxins are below guideline values for human exposure. It is safe to boat/swim in the Crooked, Deschutes and Metolius River Arms of Lake Billy Chinook at this time.
The Oregon Health Authority recommends that people continue to be cautious with their pets in the lake because toxins are still above the very low exposure levels established for dogs. (Health Advisories may still be in effect at Perry South)
Why is the lake green?
The term “Algae” refers to a broad scope of organisms. Algae can range from the microscopic single celled organisms that can be floating in a lake, to large seaweed plants that are found in the ocean, like Giant Kelp. Your common lake variety of algae is known as green algae. (This is different from the toxic blue-green algae, which is actually a form of bacteria known as Cyanobacteria, that can make some people and animals sick.)
Green algae is the single cell variety of green algae that most commonly turns Lake Billy Chinook green. These tiny little micro-organisms live off of the nutrients in the lake and use the sunlight to photosynthesize, much like the plants and trees above the water. These little organisms contain large amounts of “chlorophyll,” which is a pigment that makes all plants green. (Chlorophyll is the essential pigment that allows plants to photosynthesize sunlight into food.)
When the weather and the water temperature warm up, typically in late spring or early summer, the entire lake can resemble a huge pot of split pea soup. This occurs when the number of algae organisms begin to reproduce at an astounding rate. These algae are able to reproduce because there is an excess of nutrients found in the water. The algae can become thick and doesn’t smell very good. Algal blooms are a naturally occurring phenomenon, and are essential to the overall health of the lake. This excess bloom of plant life provides tons of food for other microorganisms and fish.