Blue-green algae bloom found in Yellowknife

Kim Harrower was walking her 12-year-old Labrador Retriever along the Rotary Boardwalk in Yellowknife on Tuesday when she noticed something unusual on the shoreline.

"I saw this kind of blue-green stuff near the waterline, and it looked like paint... and I was a bit concerned it could be a chemical that my dog shouldn't be near," Harrower said.

Harrower didn't report it but later found a Facebook post from the N.W.T.'s department of Environment and Climate Change (ECC) about a cyanobacterial bloom, or blue-green algae, in Great Slave Lake. 

The department says cyanobacteria occur naturally in the N.W.T., and can proliferate in certain conditions and form blooms that can release toxins that are potentially harmful to animals and humans.

Jeffrey Cederwall, an aquatic quality scientist with the department, said ECC and the Canadian Coast Guard collected samples for testing from some spots.

"Spottings varied between Rotary Parks at the Dettah ice road entrance, along Rotary Park, through to the Old Town public boat launch, and up to the Latham Islands in the narrows," Cederwall said.

Cederwall says they haven't yet identified potential toxins.

This isn't the first time local residents have seen such blooms. Two years ago, resident Bonnie Lee saw a similar blue algae in Yellowknife Bay near Tin Can Hill. Lee said she was shocked to see long strands of blue-green substance along the shoreline.

"My dog was in that water and drank some of it, but thankfully nothing happened to her later," Lee said.

Cederwall advises people to avoid drinking or swimming in the water, and to be cautious with pets.

"Dogs might not see that same area as a potential risk and might drink the water... Pets can be at a higher risk," Cederwall said.

"If you see thick scum that looks like pea soup or spilled paint, that's where there is a higher potential risk," Cederwall said.

He expects lab results in a few days. He says such algal blooms may potentially occur again until mid-September.