Blue-Green Algae Precautions
Blue-green algae, also known as cyanobacteria, is toxic to people and pets and should be avoided. Before swimming, always take an overall look at water conditions. Conditions can change quickly, and posted signs may not always reflect real-time water quality.
Spotting a Blue-Green Algae Bloom
Blue-green algae can appear blue-green, reddish-purple, or brown, and cause the water to be murky. View photos of blue-green algae.
When environmental conditions are just right, blue-green algae can grow very quickly in number. Most species are buoyant and will float to the surface, where they form scum layers or floating mats.
- Do not swim in water that looks like "pea soup", green or blue paint, or that has a scum layer or puffy blobs floating on the surface.
- Do not boat, water ski, etc. over such water (people can be exposed through inhalation).
- Do not let children play with scum layers, even from shore.
- Do not let pets or livestock swim in, or drink, waters experiencing blue-green algae blooms.
- Do not treat surface waters that are experiencing blue-green algae blooms with any herbicide or algaecide-- toxins are released into the water when blue-green algae cells die.
If You Have Been in the Water with Blue-Green Algae
- Rinse off well when you get out.
- If you have symptoms you think are due to contact with the blooms, call your health care provider or Poison Control Center at 1-800-222-1222.
Tips for Dog Owners
Dogs that come into contact with algal blooms can get sick and sometimes die because their bodies are smaller and they tend to swallow a lot of water.
- Always look at water conditions before letting your dog swim or wade.
- Provide your dog a fresh water source to minimize the amount of lake water they drink.
- Rinse your dog off as soon as possible after being in the water. Since dogs often lick their fur, they can ingest toxins even after they are dry.
If your dog has been in the water near an algae bloom, call your vet if they seem ill afterwards.
Reducing Frequency and Intensity of Blue-Green Algae Blooms
There are no quick or easy remedies for the control of blue-green algae once they appear in a lake or pond. Reducing the amount of nutrients that wash into our lakes and ponds will eventually reduce the frequency and intensity of blue-green algae blooms, but it may take a long time and a lot of community involvement to effectively change the nutrient concentrations in a water body.
You can help reduce nutrient concentrations by promoting the following practices:
- Minimize the use of lawn fertilizers.
- Do not use phosphate-containing fertilizers.
- Perform routine maintenance on your septic system.
- Prevent yard debris like leaves and grass clippings from washing into storm drains.
- Maintain native vegetation along shorelines as buffer areas to help filter run-off.