Cyanobacteria, formerly known as blue-green algae, is contaminating Clear Lake, in Lake County, California. The microorganisms are capable of rapid population growth under ideal conditions, resulting in a "bloom."
The microscopic beings thrive in conditions of high nutrition and abundent sunlight. These blooms can discolor water, and lead to buildup of slime and scum, which can collect on shorelines. Such events can play havoc with public beaches in need of revenue from tourists.
Microcystis and Aphanizomenon were two varieties of cyanobacteria discovered in various locations around Clear Lake. Some varieties of blue-green algae are harmful to humans, pets and wildlife, while others are not. Even non-toxic forms of the microorganisms can deplete the oxygen supply of waterways, potentially harming wildlife. There is no easy way to distinguish toxic from non-toxic varieties, so exposure to any form should be avoided. Showering is usually advised immediately after swimming in any lake, as cyanotoxins from algae could be present, even if it is not visible in the water.
"It is easy to avoid exposure to harmful toxins and still possible to enjoy recreational activities in and around the lake. People and pets should not swim or wade through algal scums," Lake County News reported.
Lake County Water Resources officials are managing the outbreak, and collecting data to share with the public.
Clear Lake is a fresh water lake, fed by a flow from springs in Soda Bay, as well as numerous streams. The only outlet for the water body is Cache Creek. Largemouth bass, channel catfish and brown bullheads are among the wide range of fish found in the waterway that could be affected by the bloom.
Cyanobacteria are microscopic bacteria that exist in both single-cell and multicellular varieties. The tiny living beings perform photosynthesis, like plants, in order to derive energy. They are found in fresh- and saltwater environments around the globe.
"Effects [of exposure to cyanotoxins] can include liver damage, kidney damage, neurological effects, or skin irritation. In addition, a wide range of nonspecific symptoms, such as gastrointestinal upset, headache and flu-like symptoms, and eye/ear irritation, may occur," Lake County Water Resources officials wrote on their Web site.
That agency is studying the outbreak to determine the extent of the contamination.
Microcystis led to the demise of sea otters of the coast of central California several years ago. The deaths of several dogs during outbreaks have also been traced to cyanotoxins created by blue-green algae.
Similar contamination is an annual event in the area, and there is disagreement among the local population over how the year compares to past occurrences.