You Can Know How to Protect Your Family and Pets from Cyanobacteria

News Release


For Immediate Release: July 5, 2018

Media Contact:
Ben Truman
Vermont Department of Health
802-951-5153 / 802-863-7281


You Can Know How to Protect Your Family and Pets from Cyanobacteria
Learn what “blue-green algae” looks like so you can avoid a potentially toxic bloom

BURLINGTON – Cyanobacteria, more commonly known as blue-green algae, can harm humans and animals. In large numbers, these tiny microorganisms can form blooms on the water’s surface and wash up along shorelines. Vermont health officials want to be sure you know how to identify and avoid a bloom, and what to do if you or a pet comes in contact with cyanobacteria. 

Warmer weather creates ideal conditions for cyanobacteria to grow in Lake Champlain and elsewhere. Blooms are usually green or blue-green, and can make the water look like pea soup or spilled paint, but can be other colors and consistency too. In recent years, cyanobacteria blooms have occurred most often in northern sections of Lake Champlain—such as St. Albans Bay and Mississquoi Bay, as well as inland waters, notably, Lake Carmi.

People are encouraged to go to to see a video of what cyanobacteria look like, and photos of what is – and isn’t – a bloom.

Swimming or wading in water with cyanobacteria may cause minor skin rashes, sore throats, diarrhea, stomach problems, or more serious health problems. Children and pets are at higher risk of exposure because they are more likely to play near the shoreline where cyanobacteria accumulate, and drink water while swimming. Pets can also lick and swallow cyanobacteria that may be caught in their fur.

“The best way to protect yourself from exposure is to know what cyanobacteria look like, pay attention to posted signs at beaches, and stay out of the water when you think you see a bloom,” said Department of Health Commissioner Mark Levine, MD. “If you think there may be a bloom in the water, here’s the best plan – when in doubt, stay out.”

If you do come in contact with cyanobacteria, rinse yourself off thoroughly as soon as possible. If you have health concerns from possible exposure, talk with your health care provider.

This season’s monitoring of the state’s waters for cyanobacteria and testing for cyanotoxins started in mid-June. The Health Department works closely with other agencies, environmental organizations, recreational site managers, town health officers and drinking water system operators. Monitoring partners include the Vermont Department of Environmental Conservation and the Lake Champlain Basin Program, as well as the Lake Champlain Committee, which for years has trained hundreds of volunteer monitors.  

People can check recent cyanobacteria reports at the department’s online Cyanobacteria Tracker Map. This interactive tool logs monitoring reports from sites in and along Lake Champlain and various inland lakes in Vermont, including recreational swimming areas. Sites are identified as "Generally Safe" or indicated as having cyanobacteria presence with "Low Alert" or "High Alert." The Health Department also posts a weekly summary of conditions.

If you see cyanobacteria:

  • Do not come in contact with the water.
  • Do not let pets or livestock swim in or drink the water.
  • Read and obey posted signs at beaches.
  • Report blooms to beach managers, town health officers, or the Health Department.

To report a bloom to the Health Department, send an email to Please include pictures of the bloom, and if possible, an image of a map noting the location of the bloom or the closest street address.

Learn about cyanobacteria and what it looks like at

For more tips and information about staying healthy while enjoying summer in Vermont, visit

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