Kim Harrower was walking along the Rotary Boardwalk in Yellowknife with her 12-year-old Labrador Retriever on Tuesday when she noticed something unusual on the shore.
“I saw this blue-green stuff near the waterline, it looked like paint … and I was a little worried it might be a chemical that my dog shouldn’t be near,” Harrower said.
Harrower did not report the incident, but later found a Facebook post from the Northwest Territories Department of Environment and Climate Change (ECC) about a cyanobacterial (blue-green algae) bloom in Great Slave Lake.
According to the agency, cyanobacteria occur naturally in the Northwest Territories and, under certain conditions, can proliferate and form blooms that can release toxins that are potentially harmful to animals and humans.
Harrower with her dog. (Image submitted by Kim Harrower)
Jeffrey Cederwall, a water quality scientist with the department, said ECC and the Canadian Coast Guard have collected samples for testing at some locations.
“Sightings varied between the Rotary Parks at the entrance to the Dettah Ice Road, along Rotary Park, to the public boat ramp in the old town and up to the Latham Islands in the strait,” Cederwall said.
Cederwall says they have not yet identified any potential toxins.
This is not the first time residents have seen such blooms. Two years ago, local resident Bonnie Lee saw a similar blue-green algae in Yellowknife Bay near Tin Can Hill. Lee said she was shocked to see long strands of a blue-green substance along the shoreline.
“My dog was in the water and drank some of it, but luckily she was fine later,” Lee said.
Bonnie Hill saw a green substance near Tin Can Hill 2 years ago. (Image submitted by Bonnie Hill)
Cederwall advises people to avoid drinking or swimming in the water and to be careful with pets.
“Dogs may not see a potential risk in this area and may drink the water… Pets may be at higher risk,” Cederwall said.
Cederwall adds that such algal blooms are becoming more common in the Northwest Territories due to climate change, warmer waters and sometimes lower water levels.
“If you see thick foam that looks like pea soup or spilled paint, there is a higher potential risk there,” Cederwall said.
He expects the laboratory results in a few days. He assumes that such algal blooms could occur again by mid-September.
