Cyanobacteria Blooms (Blue-Green Algae)

Cyanobacteria Blooms

Kern County Public Health is urging boaters and recreational users to avoid direct contact with or use of waters affected by harmful algal blooms (HABs) in Lake Isabella in Kern County.

The recommendation is based on the potential health risks from toxins produced by cyanobacteria, which is currently blooming in the lake. Algae and cyanobacteria, the organisms that cause HABs, have existed for billions of years as essential components of freshwater ecosystems. But when certain conditions favor their growth – warm temperatures, stagnant water flows, excessive nutrient inputs – they can multiply very rapidly creating “blooms.” These blooms can produce toxins, and taste and odor compounds, that pose health risks to humans and animals. When blooms pose a risk, they are referred to as harmful algal blooms (HABs).

A cyanobacteria bloom has been observed in the main body of the lake and along the shorelines of Paradise Cove, Kissack Cove and French Gulch.

On June 19, staff from the Central Valley Water Board and the Kern County Environmental Health Services collected water grab samples from Paradise Cove, Kissack Cove, and French Gulch.

Two cyanotoxins (microcystin and anatoxin-a) were detected in Paradise Cove and Kissack Cove.  The microcystin concentrations at both sites exceeded the state’s Danger health advisory level for recreational waters, which recommends against any water contact including swimming and skiing.

Red danger signs are posted in these areas.

The French Gulch site had a microcystin detection that was above the state’s Caution advisory level, which presents a health concern for pets and children.

The Caution advisory level recommends that pets are kept out of the water and away from the shoreline and children are kept out of the shallow shoreline areas where the bloom may be concentrating. Be aware that bloom conditions can change rapidly and wind and waves may move or concentrate the bloom into different regions of the lake.

Lake Isabella Map

Yellow caution signs are posted in this area. See the warning signs:

Lake Evans

In Lake Evans, testing was conducted on June 19, and no cyanobacteria were observed in the sample but there was a low detection of Anatoxin-a (0.87 µg/L), which any detection triggers the state’s Caution advisory (mainly for pets and children).

Yellow caution signs are posted in this area.

See the warning sign here:

Lake Evans Map

Cyanobacteria, also called blue-green algae, are microscopic organisms found naturally in all types of water. These single-celled organisms live in fresh, brackish (combined salt and fresh water), and marine water. These organisms use sunlight to make their own food. In warm, nutrient-rich (high in phosphorus and nitrogen) environments, cyanobacteria can multiply quickly, creating blooms that spread across the water’s surface. The blooms might become visible.

Cyanobacteria blooms form when cyanobacteria, which are normally found in the water, start to multiply very quickly. Blooms can form in warm, slow-moving waters that are rich in nutrients from sources such as fertilizer runoff or septic tank overflows. Cyanobacteria blooms need nutrients to survive. The blooms can form at any time, but most often form in late summer or early fall.

You might or might not be able to see cyanobacteria blooms. They sometimes stay below the water’s surface, they sometimes float to the surface. Some cyanobacteria blooms can look like foam, scum, or mats, particularly when the wind blows them toward a shoreline. The blooms can be blue, bright green, brown, or red. Blooms sometimes look like paint floating on the water’s surface. As cyanobacteria in a bloom die, the water may smell bad, similar to rotting plants.

Cyanobacteria blooms that harm people, animals, or the environment are called cyanobacteria harmful algal blooms. Harmful cyanobacteria blooms may affect people, animals, or the environment  by blocking the sunlight that other organisms need to live. Cyanobacteria blooms can steal the oxygen and nutrients other organisms need to live. By making toxins, called cyanotoxins. Cyanotoxins are among the most powerful natural poisons known. They can make people, their pets, and other animals sick. Unfortunately, there are no remedies to counteract the effects. You cannot tell if a bloom has toxins by looking at it.

  • Do not let your pets or livestock graze near, drink, or swim in water where you see cyanobacteria blooms, foam, or scum on the surface.
  • If your animal gets in water with a bloom, immediately wash it off with clean water. Do not let the animal lick alg off of its fur.
  • Call a veterinarian if your animal shows any of these symptoms of cyanobacteria poisoning: loss of energy, loss of appetite, vomiting, stumbling and falling, foaming at the mouth, diarrhea, convulsions, excessive drooling, tremors and seizures, or any unexplained sickness that occurs within a day or so after being in contact with water.

More information HERE

For more information on cyanobacteria, click here.

For information on animal health and safety:

For information on human health and safety:

For more information on cyanobacteria blooms:

Call CDCInfo: 800-CDC-INFO (800-232-4636)

or Contact your local or state health department or Call the Poison Information Center (800-222-1222)

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