Blue-Green algae in Cross Lake in southern part of M.D.

Pearl Lorentzen
Lakeside Leader

One lake in the M.D. of Lesser Slave River has blue-green algae blooms. This is Steele (Cross) Lake east of Flatbush.
The warning says that areas of the lake without visible algae blooms can still be used.

As of July 16, there are nine blue-green algae (cyanobacteria) warnings in the AHS North Zone, which covers the top half with Hwy. 16 as its southern border.

The first warning was issued on June 11. This was for Steele (Cross) Lake. Until July 8, there were only two others. However, from July 8 to 15, there were six more added. None of the new lakes are in the M.D. of Lesser Slave River.

As of July 16, there were 20 blue-green algae warnings in Alberta in 2021. The first was issued on June 11 and the last on July 15.

Last year, the first two lakes in the M.D. of Lesser Slave River to get blue-green algae blooms were Steele (Cross) Lake and Lawrence Lake, says an August 19, 2020 Leader article.

In a Global News article, University of Alberta aquatic ecology professor Rolf Vinebrooke says, that the number of 2021 advisories are comparable to other years, but higher than 2020 because it was cloudier, cooler, and wetter.

“Blue-green algae is naturally occurring, and often becomes visible when weather conditions are calm,” say the warnings. “Appearing like scum, grass clippings, fuzz or globs on the surface of water, blue-green algae can be blue-green, greenish-brown, brown, and/or pinkish-red, and often smell musty or grassy.”

Symptoms of exposure include: “skin irritation, rash, sore throat, sore red eyes, swollen lips, fever, nausea and vomiting and/or diarrhea,” says AHS. “Symptoms usually appear within one to three hours and resolve in one to two days.
Symptoms in children are often more pronounced; however, all humans are at risk of these symptoms.”

AHS recommends staying out of the water when the algae is visible, and to immediately wash off with tap water after exposure, not feeding pets fish or fish trimmings caught in lakes with advisories, and only eating fillets not full fish caught in lakes with blooms.

For more information and to report algae, contact Health Link (811) or see

Blue-green algae blooms for previous years on Lesser Slave Lake. If you see it, avoid it and contact AHS.

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