Effective October 4, 2012, all blue-green algae advisories for Alberta lakes have been lifted.

Future advisories will be posted on this page.

Up-to-date health advisories are posted here:

What is blue-green algae?

Blue-green algae (also known as cyanobacteria) is a common, naturally occurring bacteria.

Under certain conditions, such as when there are enough nutrients in the water and the days are sunny and hot, the blue-green algae may multiply to the point that a bloom is visible.

Why is blue-green algae a problem?

When the blue-green algae cells die, they release cyanotoxins which can stay in the water even after the blue-green algae bloom is no longer visible.

It is the cyanotixins that cause health issues that lead to the advisory.

Is blue-green-algae a threat to my health?

It can be. The most common complaints that have been reported after exposure to blue-green algae are:

  • Nausea
  • Skin rashes
  • Intestinal distress
  • Disorientation
  • Eye irritation
  • Numbness
  • Fatigue

How would I be exposed to blue-green algae?

If you’re at an affected lake, contact to blue-green algae can come through:

  • Swallowing the water - intentionally or accidentally
  • Skin contact
  • Breathing it in when swimming, water-skiing or jet-skiing

Is blue-green algae a threat to my pets?

Yes, animals can be affected if they drink the water from lakes with blue-green algae.

Domestic and wild animals increase their exposure to blue-green algae when they drink deeply from the affected lake. This can lead to cyanobacteria poisoning.

How can I tell if there’s blue-green algae in a lake?

Blue-green algae can create a bloom which is visible in the water. However, the bloom can move or sink and no longer be visible.

If an advisory for the lake has been issued, avoid contact with that lake even if you can’t see the blue-green algae bloom.

How does blue-green algae affect fish?

There are some differences in the effects of blue-green amongst fish species. Generally, there are two adverse effects on fish that have been observed:

  • When the blue-green algae dies, the decomposition process decreases the dissolved oxygen in the lake. The lack of oxygen can lead to a die-off of fish.
  • The blue-green algae can cause physical problems to the fish, and accumulate in the fish liver.

Should I eat fish caught from a lake with blue-green algae?

Fish that have been affected by the blue-green algae will have an abnormal odor and/or taste.

There have been no documented cases of humans being poisoning by fish from lakes with blue-green algae blooms. However, Environment and Sustainable Resource Development recommends caution in consuming fish from affected lakes.

For additional information on blue-green algae, see:

Updated: Oct 22, 2012