Blue-green algae are not something you want to be swimming in. It can often be found in lakes. Here are some facts to know about blue-green algae to keep you healthy when you go.

What are blue-green algae?

Blue-green algae can also be called cyanobacteria and have the nickname “pond scum.” It’s bacteria that can often be found in lakes, ponds and slow-moving warm water streams. In certain environmental conditions, blue-green algae can grow quickly. Most species will float to the surface to form layers or floating mats, which is called “algae bloom.”

What causes blue-green algae blooms to form?

Several factors play a role in blue-green algae blooming. The following things help it grow:

  • Warm temperatures
  • Exposure to sunlight
  • Pollutants in the water

When the weather’s warmer, water cannot mix. This means that there is little or no motion in the water making it easier for algae to form.  Sunlight causes carbon dioxide to turn into sugars. This acts as its energy source. Nutrients like phosphorus and nitrogen formed from pollutants like fertilizers and sewage runoff help blue-green algae bloom too. Blooms occur in the late summer and early fall. 

Why you should be concerned about coming in contact with algae

Only 30 to 50 percent of algae is nontoxic. Several forms produce cyanotoxin, which is harmful to both animals and humans. Exposure to these toxins can cause these symptoms:

  • Headaches
  • Fever
  • Nausea
  • Diarrhea
  • Skin Irritation
  • Allergic reaction in the eyes, ears, nose or throat 
  • Ingestion can cause neurological, liver or kidney complications

According to the Center for Disease Control, exposure happens in a couple of ways. Ingestion, inhalation, skin contact and eye exposure are the main ones. Washing off and exposing yourself to clean freshwater can help. Although, it’s always best to seek medical help for more severe cases if you suspect you have been exposed to blue-green algae.

How can I prevent the growth of blooms?

There are a few things you can do to prevent the growth of blooms:

  • Limit the use of chemical fertilizers near water to prevent runoff
  • Properly care for and maintain your septic system
  • Plan trees or shrubs around shorelines and streams to prevent runoff
  • Contact your local health authority if you suspect sewage has come in contact with a body of water

Chemical fertilizers can cause pollutants to get into the water. As mentioned earlier, this makes for a breeding ground for blue-green algae. Your septic system contains bacteria that can end up in the water, which is why you should make sure it’s working and up to date. Trees and shrubs can act as a barrier between the water and its surrounding area. If you notice water around you that’s polluted, contacting your local health authority can prevent it from becoming more polluted!