Warning signs advising people to be cautious around the water are being removed from Belwood Lake Conservation Area.
The Grand River Conservation Authority announced Monday that results of tests taken last week showed non-detectable levels of the toxin microcystin in the reservoir water.
That means there is no risk to swimmers, boaters, and anglers from microcystin.
However, GRCA officials suggest that lake users should continue to avoid algae mats on the shoreline, algae “scum” floating on the surface or any other visible algae. The green-blue algae are the source of microcystin.
The warnings went into effect on Aug. 13 after water samples from the lake showed levels of microcystin higher than those recommended for recreational use.
The signs were posted by Wellington-Dufferin-Guelph Public Health.
Park Superintendent Derek Strub noted that there were no fished killed during the bloom
Microcystin is a toxin that is released by blue-green algae as they die. It can cause skin rashes after contact or illness after being ingested by people or animals.
Algae blooms are a natural phenomenon. They tend to occur during hot dry weather. Algae feed on phosphorous, a chemical found naturally in soil as well as in manure, fertilizers and human waste.
GRCA water quality staff believe that runoff from heavy rains in June may have carried additional phosphorous into the reservoir and that hot weather in July accelerated the growth of algae.
More information on blue-green algae is available in the Newsroom section of the GRCA website at www.grandriver.ca.
