Blue-Green Algae

Algae are naturally occurring, plantlike organisms that can be found in all types of natural waters. Algae plays a vital role in healthy aquatic ecosystems by forming the base of the food web and generating oxygen. Overgrowths of algae, called a 'bloom', occur when environmental conditions cause algae to grow rapidly. Blooms consume oxygen in the water and block sunlight which is harmful to the aquatic ecosystem. Certain blooms can also produce toxins and harmful gases that are harmful for people and animals. 

Cyanobacteria, also called blue-green algae, or toxic algae, is a phytoplankton commonly found in freshwater. Cyanobacteria blooms can produce cyanotoxins that can damage the nervous system (neurotoxins) and liver (hepatotoxins). It is typically green and blue in color, but can also be brown, orange and yellow depending on the type of plankton. It can grow on rocks beneath the water, as well as on the surface of the water, resembling foam, scum, and spilled paint. 

Not all blooms are toxic, but only laboratory testing can confirm whether a bloom is toxic or not. Because of this, it is important to stay up to date on recent testing, recognize the signs of possible blooms and exposure, and take proper precautions when on or near the water. 
What causes blue green algae?

Blooms typically occur during warm summer months. Though they can occur naturally, certain factors can cause it to grow rapidly, including:

  • Warm water temperatures.
  • Slow flowing water.
  • Excess nutrients in the water; including agriculture runoff, urban runoff, and human and animal waste.
  • Rainfall: Excess rainfall can add runoff of excess nutrients to the water. Low rainfall can make it more condensed.
  • Excess Sunlight
What are the signs of a bloom?
Signs of a toxic algae bloom can include dead fish, waterfowl, or other animals on or near the shoreline. It can also include sudden unexplained sickness or death of a pet.
How can I be exposed?

Exposure can occur through ingestion, inhalation, and contact with skin or eyes. This can include:

  • Swallowing, ingesting, or using contaminated water.
  • Eating fish or shellfish contaminated with toxin.
  • Breathing in droplets of contaminated water
  • Skin or eye contact during recreational activities like swimming or boating.

Pets, in particular, are at higher risk because of their size and the increased possibility of water ingestion due to drinking contaminated water or licking their fur. 
What are the symptoms?
Symptoms can vary in type and severity based on several factors, including the type of exposure, the amount of toxins one is exposed to, and type of cyanotoxin present. 

Those exposed by touching contaminated water or breathing in droplets of contaminated air may experience irritation of the: 

  • Skin
  • Eyes
  • Nose
  • Throat
  • Lungs

Exposure through swallowing/drinking contaminated water or eating contaminated fish/shellfish can cause different symptoms based on the type of toxin. 

Neurotoxin (nerve) poisoning can cause symptoms within 15 minutes of exposure and include: 

  • Numbness and tingling in lips, fingers, and toes.
  • Dizziness / lightheadedness
  • Speech disturbances
  • Muscle twitching
  • Staggering
  • Weakness

Hepatotoxin (liver) poisoning symptoms may take hours or days to develop and include:

  • Abdominal pain
  • Diarrhea
  • Vomiting
  • Jaundice

If you see symptoms, seek care immediately. If you think you or your pet may have been exposed, contact your primary care provider or veterinarian immediately.