Reporting harmful algal blooms (HABs)

When you’re out sampling with your Water Rangers kit and enjoying nature, the last thing you want to encounter is green, smelly algae. But algal blooms are more than a nuisance- they can make people and animals very sick if the contaminated water is consumed. This can be the case with certain species of cyanobacteria (blue-green algae) that can produce toxins called microcystins (among others). When these toxins are ingested they can wreak havoc on the body’s system by causing gastrointestinal issues, headaches, and organ failure (specifically of the liver and sometimes the kidneys).

Cyanobacteria bloom.
Cyanobacteria is commonly known as blue green algae.

Common signs of cyanobacteria

  • “Pea soup” consistency with a bluish green colour. 
  • Found floating & swirling in warm, shallow water near shores & docks.
  • If it has roots, identifiable leaflets or looks stringy, it’s most likely not cyanobacteria but an actual species of algae.

Suspect harmful algal blooms (HABs)?

Do not swim or drink the water if you suspect there is the presence of cyanobacteria, and make sure to prevent children and pets from entering the water.

If you have gone swimming, shower as soon as possible and call your provincial health number for advice (listed below).

Next step: report!

Links to Regional Health Authority contact information, provincial health numbers and cyanobacteria information for each province & territory:

*Cyanobacteria information specific to Yukon, Northwest Territories and Nunavut was not publicly available on provincial government websites.


“Yukon, Northwest Territories and Nunavut have not noted problems with cyanobacteria and microcystins in drinking water supplies in their jurisdictions (Northwest Territories Department of Health and Social Services, 2012; Nunavut Health and Social Services, 2012; Yukon Environmental Health Services, 2012).”

According to Government of Canada’s website.

Don’t forget to take pictures!

We don’t have a way to test for cyanobacteria in the field (yet), but that doesn’t mean you can’t keep track of your observations. Take pictures of suspected algae and upload them to our data platform using the “report an issue” feature. Note: this feature is only available on our website, and not on our app!

Check out previously recorded issues