Keep away from blue-green algae, warns GRCA

A blue-green algae bloom. (Courtesy: Grand River Conservation Authority)

The Grand River Conservation Authority is warning swimmers and campers about the dangers of blue-green algae.

They said a small bloom was spotted this week near the west side of Shand Dam at the Belwood Lake reservoir.

Blue-green algae can be found in lakes, reservoirs and rivers. Sometimes, especially in the late summer and early fall, the bacteria can reproduce rapidly and form large blooms, also call mats or scums. The algae often appears like thick pea soup or spilled paint on the surface of the water. The smell has been compared to rotting garbage.

“Blue-green algae thrive on nutrients from fields and lawns that find their way into local waterways and reservoirs during heavy rainfall and spring melts and cause their populations to grow rapidly,” the GRCA said in a media release. “Some varieties of blue-green algae can produce toxins that are harmful to both people and pets.”

While the bacteria was only found near the Shand Dam, it has, in the past, also been reported at Belwood Lake, Conestogo Lake, Guelph Lake, Woolwich reservoirs and Snyder’s Flats. Signage has posted in those locations to let visitors know that they should avoid blue-green algae.

The GRCA shared some safety tips for campers, swimmers, recreational users and cottagers:

• Keep children and pets away from the algae.
• Avoid contact with the algae.
• Do not eat fish from the lake.
• Do not use the water for drinking or any other purpose.
• Boaters and recreational users should avoid touching the algae.
• Don’t swim in areas where you see scum.