F.A.Q about Blue Green Algae (Cyanobacteria)

(This information is excerpted from data supplied to the Master Property Owner’s Association of Wonder Lake, Illinois)

Q: What are blue green algae (cyanobacteria)?

A: Blue green algae are a group of organisms that are among the oldest on the planet. They can live in freshwater or salt water. Most people know them as “pond scum.” These blue green algae can actually be many colors including green, red, orange, or brown. The appearance of “blooms”, or very large numbers of algae, can look like fine grass clippings or small clumps, or just add a color to the water. Blue green algae share many characteristics of bacteria, which has led to them being known as “cyanobacteria.”

Q: What causes these organisms to form “blooms”?

A: Blue green algae can multiply quickly in lakes with high nutrient levels, particularly when the water is warm and the weather is calm. This population explosion causes “blooms” of blue-green algae that turn the water green, often with floating layers of scum. A blue green algae bloom can also lie below the surface of the water. Blooms can spontaneously disappear or move to different parts of a pond or lake.

Q: Are all “blooms” toxic?

A: There are thousands of blue green algae species and many more are still being discovered. Most do not produce toxins that are harmful to people or animals. However, some types of blue green algae produce toxins within their cells which are released when the cells die off or are ruptured. It is not clear why blue green algae make these toxins.

Q: Does all blue green algae release dangerous toxin?

A: No. You cannot look at a bloom and tell if it is toxic. You cannot look at a bloom and tell how dangerous it is to you or your pet, either. You cannot assume that if other people are in or near the water, that there is NOT a dangerous bloom.

Q: How long can dangerous toxins be present in the water?

A: They can persist even after the collapse of algal blooms in the late summer and early fall. Colder temperatures and decreased light intensity results in decreased rates of breakdown.

Q: Are there different types of toxins from harmful algal blooms?

A: Yes, there are many types of blue green algae toxins, including toxins that can affect the nervous system, the skin, the liver, the digestive tract, and the respiratory system. ALL can affect both you and your pet.

Q: What is Microcystin toxin?

A: Microcystin is a particularly noxious toxin that is released by some species of blue-green algae, or cyanobacteria. People and pets can get sick from microcystin toxin if they have direct contact with a blue green algae bloom, by either intentionally or accidentally swallowing water, by having direct skin contact (as when swimming, wading, or showering), or by breathing airborne droplets containing the toxins, such as during boating or waterskiing. Pets and other animals that drink from the water’s edge, where scum layers accumulate, can be exposed to deadly levels of microcystins. Pets can get sick if they have been swimming in water where algal blooms have been and ingest significant amounts of microcystins by licking themselves after leaving the water.

Q: What are the symptoms of microcystin poisoning?

A: Microcystin poisoning can cause breathing problems, stomach upset, skin reactions, and even liver damage. Getting blue-green algae/microcystin on the skin may produce a rash, hives, or skin blisters (especially on the lips and under swimsuits). Swallowing water containing blue-green algae/microcystin may cause gastrointestinal symptoms such as stomach pain, nausea, vomiting, diarrhea, severe headaches, and fever. Inhaling water droplets containing blue-green algae/microcystin can cause runny eyes and nose, cough, and sore throats.

Q: What should I do if I think my pet has algae poisoning symptoms?

A: Call your vet, NOW. if your vet's office is closed, contact your local emergency veterinary care provider.