What is Cyanobacteria?

View our cyanobacteria presentation, here.

Cyanobacteria, commonly referred to as blue-green algae, are single-celled microscopic organisms that live in all types of water and use sunlight to produce food. Cyanobacteria blooms occur in slow- moving, warm water, with high levels of phosphorus and nitrogen. Excessive nutrient loading provides conditions for the cyanobacteria to rapidly multiply, causing blooms that can spread across an entire waterbody. These blooms can float up and down the water column and potentially produce toxins. The water may appear cloudy, bright green to dark red, and can be thick like pea soup. Cyanobacteria blooms can also affect the water quality by blocking sunlight and using up oxygen and nutrients that other aquatic organisms need to survive.

How do Cyanobacteria blooms affect me?

There is no clear or easy way to quickly determine if a bloom is toxic, therefore when blooms occur health officials advise people and pets to avoid the water. Cyanobacteria toxins are among the most powerful natural poisons known. Cyanobacteria blooms – due to this risk of cyanotoxins – can harm people, animals, the aquatic ecosystem, drinking water supplies, the economy, property values and recreational activities such as swimming and fishing. Not all cyanobacteria blooms produce toxins, however, about 1 in 5 blooms do. There are potential health risks for swimmers, boaters, pets and wildlife encountering toxins that may be produced by the algae. Pets swimming in waters containing cyanobacteria toxins may become ill or die after drinking or licking themselves. Toxins associated with cyanobacteria have been implicated as the cause of mass mortalities of fish and birds.

How do I report a Cyanobacteria bloom?

Become a citizen scientist and help report cyanobacteria bloom sightings by downloading the bloomWatch app, created by the EPA. Contact your Local Public Health Agency, CT Department of Public Health (860-509-7758), or CT Department of Energy and Environmental Protection (860) 424-3020.

Learn more about cyanobacteria through our image-rich powerpoint presentation, here.