Water Security Agency
July 10, 2024

Be Aware of Blue-Green Algae  

As temperatures increase this summer and the recreational season begins, the Water Security Agency (WSA) is reminding the public to be cautious around blue-green algae in lakes and reservoirs.

Blue-green algae is a type of naturally occurring bacteria that can be present in water bodies, particularly lakes and reservoirs. Summer heat can cause patches of harmful algae blooms that often give the water a shimmering, foamy and pea soup like appearance. The blooms may be blue-green, bright blue, grey or tan in colour. Warm temperatures can result in the quick formation of algal blooms.

If you see (or believe you see) blue-green algae in a body of water, take these precautions:

  • Avoid direct contact with water where blue-green algae blooms are occurring. If contact occurs, wash with tap water as soon as possible.
  • Do not swim or allow your pets to swim in any areas where blue-green algae is visible.  
  • Do not feed whole fish or fish trimmings from the lake to your pets. 
  • Limit or eliminate human consumption of fish organs or shellfish caught in the lake.

Algal blooms commonly occur during calm, hot weather in areas of lakes and reservoirs with shallow, slow moving or still water that has sufficient nutrients. The blooms can last up to three weeks and can be pushed around the lake or reservoir by the wind. Many of Saskatchewan’s southern lakes are prone to blue-green algae due to the high levels of naturally occurring nutrients they contain.

Direct contact or unintended consumption of algae-contaminated water can cause red skin, sore throat, cramps, nausea, vomiting and diarrhea. If you have health-related questions about blue-green algae, please contact your local Saskatchewan Health Authority environmental health office.

For more information on public beaches in Saskatchewan, please refer to the Healthy Beaches Program updates; monitoring resumes this month.

Patrick Boyle
Water Security Agency
Moose Jaw