The recent warnings on avoiding cyanobacteria in the Clearlake Oaks section of the lake has more than a few people concerned. Cyanobacteria is often called blue-green algae although it is not related to any algae species. For argument’s sake, we will refer to it as algae. It is actually a living organism and is one of the oldest living fossils in the world, dating back billions of years. It lives in the water and reproduces by photosynthesis, which means sunlight causes it to bloom and make its own food.
Even though many people hate it, blue-green algae does serve a purpose. The plant produces oxygen which all living things require. In fact, varies forms of algae produce 70 percent of the oxygen on earth and without algae we couldn’t live. Algae are actually tiny water plants that cycle normally between the bottom and the surface, floating up and sinking down. During the day, algae generates oxygen within the lake and at night it consumes oxygen. Algae are among the oldest-living organisms on our planet, going back at least 2 billion years. Without question algae are one of the most important plants on earth. Not only do they produce oxygen, algae supplies food for many of the creatures in the lake. Baby fish feed on plankton that is part of algae.
Cyanobacteria can be a problem. From more than 130 species of algae and cyanobacteria identified in Clear Lake, five species of cyanobacteria can create problems under certain conditions. These problem cyanobacteria typically “bloom” three times a year — in spring, summer and late summer. Each bloom is dominated by a different species of cyanobacteria that thrives in the conditions at that time of year. The intensity of the blooms vary from year to year and are unpredictable. The problem occurs when cyanobacteria blooms are trapped at the surface and die. When this occurs, unsightly slicks and odors can be produced. Some cyanobacteria may produce cyanotoxins that can pose a range of health risks to people and animals. This is what recently happened in the Clearlake Oaks arm of the lake.
Algae is nothing new to longtime Lake County residents. Thirty years ago the algae was so thick at times you could hardly run a boat through it. Boats going across the lake would produce bright green wakes. Swimmers would leave the lake and have a green color on their bodies. Actually, Clear Lake is getting clearer. According to scientists, the lake is now clearer that it has been in the last 50 years. There are also side effects from the clearer lake and that is aquatic weed growth. Years ago when the green and blue-green algae was thick, the sunlight couldn’t reach the bottom of the lake to generate weed growth and there were very few weed mats This year because of the clearer water it is expected there will be heavy weed growth during the summer months. Fifty years ago the shoreline of the lake was covered with tules and not aquatic weeds.
Getting rid of all the algae can be a difficult task. The county doesn’t have the resources to eliminate the algae and even if the county did, it would take years. In past years the county has installed inflatable booms at the entrances of some of the harbors such as Redbud Park in Clearlake and at the boat ramp in Clearlake Oaks. The county also has used boats equipped with pressure hoses to break up the algae mats. All these methods have met with limited success. The problem with the algae, in addition to the thick mats, is the stench it creates when it rots. In some areas the stench can be so great that lakeside residents can’t sit out on their decks in the evenings. Thick algae mats can also clog up intakes on outboard and inboard motors, which can result in major damage.
Make no mistake, blue-green algae can cause serious problems for the users of Clear Lake. Depending on its stage it can cause a problem if you drink it or it comes into contact with your skin. It can also kill animals, especially dogs, that swim in the lake. Typically a dog will lick its fur after coming out of the water. If the dog has been in the blue-green algae the dog can ingest some of the algae and get very sick.
The good news is most of the cyanobacteria will be gone by the middle of September and the clear water will once again prevail. Clear Lake has been constantly changing for thousands of years and will continue to do so.
