The Grand River Dam Authority is urging caution as Blue-Green Algae is found on Grand Lake. The discovery was made in the Fly Creek arm of the lake.
The GRDA Laboratory say the algae's toxin levels are 5 times higher than what is considered toxic. The scum- like algae looks like pea-green soup on top of the water.
Contact with the algae can cause skin irritation, blisters and hive-like sores. It can cause breathing problems if inhaled.
Children are most at risk.