Edmonton

Cool spring, rainy summer means fewer blue-green-algae advisories for Alberta lakes

Less algae has grown this summer, because colder weather has prevented sunlight from reaching lakes, but that might not last long according to UofA biologist Rolf Vinebrooke.

If August is warmer and sunnier, blue-green algae could still affect Alberta lakes

A blue-green algae bloom in Oathill Lake, N.S. Cool and cloudy weather in Alberta have reduced the number of blooms across the province this summer. (Submitted by Bob Rutherford)

Alberta lakes are seeing fewer algae blooms this summer, but that might not last long, according to University of Alberta biologist Rolf Vinebrooke.

Blue-green algae are cyanobacteria that require sunlight for photosynthesis.

Cooler, cloudy weather has prevented sunlight from reaching lakes, Vinebrooke said.

"April got really cold, so the ice stayed on a number of lakes longer than normal … as a result, we've seen a delay in [blue-green algae] development throughout the course of the summer," he said.

"Blue-green algae love warm temperatures, sun, and concentrated nutrients. Rain tends to dilute nutrients and cloudy skies cool temperatures."

When blue-green algae blooms occur, the province issues advisories warning people to stay out of the water.

So far this year Alberta Health Services has released eight algae advisories compared to 27 in 2018 and 49 in 2017.

Blue-green algae produce a liver toxin and several neurological toxins that when consumed can cause nausea, respiratory distress and damage to human nerve impulses, Vinebrooke said. 

"Around the world you do hear reports of death of wildlife, domestic animals, livestock, and occasionally you do hear reports were some deaths have been attributed to this sort of problem as well," he said.

If August is warmer with less cloud cover, blue-green algae could still breakout in Alberta lakes, Vinebrooke said. 

"But if the weather remains cool and rainy, we may see fewer blooms this year."

While blue-green algae blooms are naturally occurring, climate change and human land use increase their frequency.

"The general scientific forecasts are that if climate warming continues on and human land use and exported nutrients goes relatively unabated, then we'll most likely see increasing incidences of cyanobacteria outbreaks in the future," Vinebrooke said.