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What are cyanobacteria?

Cyanobacteria is often referred to as blue-green algae, but it is actually a type of bacteria and has existed for billions of years - even considered to have played a role in the beginnings of life on land! Its presence in rivers and lakes is natural, though sometimes conditions are just right to cause excessive population growth, creating what are known as blooms. Sometimes these blooms produce cyanotoxins which are harmful to human and animal health. It is currently unclear what causes these toxins. 


ACAP Saint John

How to spot cyanobacteria

Blooms can appear in two forms:

Surface blooms appear as a green scum on the surface of the water, or even as small green flecks distributed throughout the water column.


Benthic mats are found attached to rocks at the bottom of the water body and can be present in water free from the tell-tale green flecks or surface scum. The mats can be a dark brown or blackish or green colour, and often have small bubbles on them. 

What to do?

Contact with cyanotoxins may cause skin, eye, or throat irritation, but ingestion can be much more severe. Before getting into the water, always check for signs of cyanobacteria, and ensure you keep a close eye on children or pets - dogs are especially known to be attracted to the smell of washed up benthic mats! 

Stay up to date with advisories posted by the Office of the Chief Medical Officer of Health. If you suspect cyanobacteria, you can report it to the Department of Environment and Local Government by contacting the appropriate regional office. 


ACAP Saint John

Staying informed is key to staying safe!

It is currently unclear what conditions may be causing toxic cyanobacteria blooms, but we are working to learn more so that we can protect our people and pets, and continue to enjoy our favourite activities!


Our partners over at ACAP Saint John provide helpful information such as videos and handouts with identification tips and risk reduction suggestions. Click here to learn more - stay informed, stay safe!

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