Cyanobacteria advisory in place over Eagle Lake

By John Watson Local Journalism Initiative Reporter

Residents in the vicinity of Eagle Lake are advised to avoid contact with the body of water, as a cyanobacteria advisory has been issued.

David Klassen, medical officer of health for the Calgary zone under the ministry of preventative health services, explained cyanobacteria, also known as blue-green algae, can produce toxins that can have negative health impacts both on humans and domestic animals.

“It is not actually an algae, [though] it acts similar to algae, kind of looks similar, and it also photosynthesizes, but it is actually a bacteria,” he said. “You can be exposed in different ways, but most commonly, people can be exposed through the skin, and then you can get some irritated symptoms.”

He added you can also be exposed by inhaling the toxin if it is aerosolized such as if someone is jet-skiing, or symptoms may develop if toxins are ingested.

Adverse effects may include headache, fever, muscle and joint pains, diarrhea, abdominal cramps, pain, nausea, or vomiting.

Other noteworthy symptoms, although in more rare cases, cyanobacteria exposure may impact breathing, paralysis, or liver damage. These are considered to be very unlikely. 

The most vulnerable to experience symptoms are children who are significantly exposed such as diving with their full bodies or drinking contaminated water, or pets and animals.

“The growth of blooms is impacted by a few different factors. Those include increased nutrients or high levels of nutrients such as phosphorus in a body of water, plus the warmth of the water. Warmer temperature helps it grow. Sunlight helps with photosynthesis,” said Klassen. “If there is not a ton of movement in the body of water, that can also help the growth. Usually after a body of water has been warming up throughout the summer is when we get these blooms. It is most common for the peak of these blooms to be in August.”

Cyanobacteria appears like scum, grass clippings, fuzz, or globs on the surface of a given body of water.

Consumption of fish from contaminated water bodies is also advised to be limited. Cooked fish fillets are considered safe to consume, but raw fish and trimmings should be avoided. Local fish can store toxins in their livers.

If physical contact does occur, it is recommended to wash the skin with clean tap water as soon as possible.

“The toxin in the water from cyanobacteria does not get broken down from boiling, and so we recommend not taking water from the lake for consumption. Even if you plan to boil it, that is not sufficiently safe,” said Klassen. “The advisory will stay up until it is assessed to be no longer a risk this season. That typically occurs in late fall, early winter … There is no sufficient way to break down the toxin if people are collecting the water for personal use.”

He explained the toxin naturally degrades over time, as well as diffuses into the body of water in question.

Waters of Eagle Lake where cyanobacterial bloom is not visible may still be used for recreational purposes even while the health advisory is in effect.