Algal bloom advisory issued for Calgary’s Lake Sundance

Alberta Health Services (AHS) has issued a health advisory for Lake Sundance, a private community lake in Calgary’s southeast. The advisory was issued due to the identification of cyanobacterial (blue-green algal) bloom toxins in the lake’s waters. Cyanobacteria are naturally occurring and blooms are more frequent during warm, extended summers with increased nutrients in the lake, making it an ideal environment for such growths, according to University of Calgary scientist Marc Strous.

These blooms can appear in various colours, including blue-green, greenish-brown, brown, pink or red. They can resemble scum, streaks, grass clippings, fuzz balls, paint, or pea soup and often emit a musty or grassy smell. While the lake remains accessible for recreation, residents and visitors are advised to take precautions. Common symptoms of contact with cyanobacterial blooms include skin irritation, rash, sore throat, red eyes, swollen lips, fever, nausea, and diarrhea.

These symptoms can emerge within one to three hours of exposure and typically last for one or two days, with children often experiencing more severe reactions.

Strous stated that eliminating the blooms is challenging as they naturally fade when temperatures drop or sunlight decreases, allowing the bacteria to die off. The recent gloomy weather in Calgary may aid in suppressing further bloom growth.