What Cyanobacteria Blooms Look Like

It's important to know what cyanobacteria blooms look like so you can stay away from them.

Cyanobacteria grow well in water that has high amounts of nutrients like phosphorous and nitrogen. Cyanobacteria can multiply quickly to form surface scums and dense populations known as blooms, especially during the warm days of late summer and early fall. In recent years, cyanobacteria blooms have occurred most often in northern sections of Lake Champlain — such as St. Albans Bay and Mississquoi Bay.

Cyanobacteria can make the water appear dark green, and look like pea soup or spilled paint. Blooms can also appear as white, brown, red or purple.

Watch the video below to find out how to identify cyanobacteria, and see more photos of what cyanobacteria look like and what are not cyanobacteria.

Cyanobacteria in Vermont

Cyanobacteria, also known as blue-green algae, are naturally found in fresh water in the U.S. and in Lake Champlain and other Vermont waters. Some types of cyanobacteria can release natural toxins or poisons (called cyanotoxins) into the water, especially when they die and break down.

Report a Cyanobacteria Bloom

Use the Cyanobacteria Tracker to view lake conditions near you. At many sites, observations are made weekly from early June to early October. Sites are identified as "Generally Safe" or indicated as having cyanobacteria presence with "Low Alert" or "High Alert." 

Check the Cyanobacteria Tracker Map

Cyanobacteria and Your Health

The health effects from cyanobacteria depend on the amount someone is exposed to, how they are exposed, whether toxins are being produced, and the type of toxin.

People may get rashes or other skin irritations from coming into contact with blooms. Usually these skin irritations are not associated with toxins, but from other compounds in cyanobacteria cells.

Breathing in water droplets with cyanobacteria or toxins may cause allergic-like reactions, runny noses or sore throats.

Swallowing water with high levels of cyanobacteria toxins may cause:

  • Severe stomach problems like abdominal pain, diarrhea and vomiting
  • Liver damage, which may take hours or days to show up in people or animals
  • Numb lips, tingling fingers and toes, or dizziness

Anyone who has health concerns should talk with their health care provider.

If you come into direct contact with cyanobacteria, rinse off with clean water immediately. Talk to your health care provider if you have symptoms such as skin, eye, or throat irritation, nausea, vomiting, diarrhea, allergic reactions or breathing difficulties. Report symptoms that may be related to cyanobacteria to the Health Department by calling 1-800-439-8550.

Cyanobacteria Monitoring and Conditions
More Questions About Cyanobacteria
More Information
Link
Cyanobacteria in Vermont (Department of Environmental Conservation)