Blue-green algae spotted at GRCA properties

Blue-green algae appears along the shoreline in this undated photo from the Grand River Conservation Authority (Courtesy: Grand River Conservation Authority on X)

A potentially dangerous type of bacteria has been seen at several Grand River Conservation Authority (GRCA) properties.

According to a release from the GRCA on Friday, blue-green algae was spotted at Belwood Lake, Conestogo Lake, Guelph Lake and Woolwich reservoirs.

Signs have been put up warning the public of the possible dangers.

Blue-green algae blooms are types of bacteria known as cyanobacteria. They are microscopic plant-like organism that occur naturally in lakes, ponds, rivers, streams and other bodies of water.

The algae thrives in water that is shallow, slow moving and warm.

When the algal blooms first start to grow the water may have a noticeable green or brown scum along the surface and the water may look green or like bluish-green pea soup.

Once the blooms are fully formed, they may look like spilled paint along the shoreline.

The algae often smells like fresh cut grass at first, while older blooms may give off an odour like rotting garbage.

Some types of blue-green algae produce cyanotoxins, which can be harmful to humans and animals.

Symptoms may include itchy, irritated eyes and skin from direct contact (such as swimming) and flu-like symptoms such as headache, fever, diarrhea, abdominal pain, nausea and vomiting if large quantities of the toxins are swallowed.

The GRCA urges residents to keep children and pets away from the algae blooms and avoid all contact with the substance. Fish from the impacted bodies of water should not be eaten and the water should not be used for any purpose, including drinking.