Alberta Health Services (AHS) issued a blue-green algae advisory for Cochrane Lake, Aug. 2.
“As part of our routine monitoring of lakes in Southern Alberta, we discovered the presence of blue-green algae in the water,” said AHS Communications Officer Shannon Evans.
Blue-green algae are microscopic organisms that are naturally present in lakes and streams in low numbers, but can increase rapidly with warm temperatures, said Medical Officer of Health Dr. Judy MacDonald.
“When the water receives a lot of sunlight, the algae can form blooms that will discolour the water or produce scum on the surface,” she added.
“It’s a natural phenomenon that has to run its course. It’s up to nature to decide when the lake will be back to safe conditions,” said MacDonald, who predicts that may not be until October when frost hits.
The blue-green algae produce a toxin that can cause illness to animals or humans that come into contact with the water. According to the advisory, symptoms usually appear within one to three hours and resolve in about two days. They include skin irritation, rash, sore throat, sore red eyes, swollen lips, fever, nausea, vomiting or diarrhea.
Officials are advising area residents and visitors to the lake and their pets to stay away from the shores, not swim or wade in the water, limit consumption of fish from the lake and not allow pets to drink the water.
“People also need to be aware that boiling water that’s been contaminated with blue-green algae does not inactivate the toxin. For the safety of pets as well, it should not be used for drinking water,” said MacDonald.
The advisory cautions that people who consume contaminated water as a primary source for drinking water can develop serious illnesses such as liver damage.
Because water from Cochrane Lake is being pumped into nearby Horse Creek, officials say they are in the process of monitoring other bodies of water that could be impacted.
“If there was an issue, an advisory would be issued for that as well,” said Evans.
Severn Lake, located northeast of Calgary, and Eagle Lake, located east of Calgary were also placed under the Aug. 2 advisory.
For more information, residents can call Health Link Alberta at 1-866-408-5465.