The Grand River Conservation Authority (GRCA) has issued a public advisory after observing suspected blue-green algae at Belwood Lake reservoir. The GRCA urges individuals to steer clear of swimming in areas where the algae may have gathered. According to the GRCA, a possible small bloom of blue-green algae was detected near the lake’s boat launch.
The organization explained that the warm summer weather provides ideal conditions for algae to develop and flourish in large bodies of water. Tuesday saw temperatures climbing to a high of 28°C, with a humidex making it feel more like 37°C, as reported by Environment Canada.
When blue-green algae starts to proliferate, a visible green or brown scum forms on the water’s surface, giving it a green or bluish-green appearance resembling pea soup. Additionally, once blue-green algae are fully bloomed, it can resemble spilled paint along the shoreline. The smell of a new bloom is akin to fresh cut grass, while an older bloom may emit an odor similar to rotting garbage.
Visitors and cottagers at Belwood Lake are advised by the GRCA to take precautions, including avoiding contact with the algae, keeping children and pets away from it, refraining from consuming fish caught in the lake, abstaining from using the water for drinking or any other purpose, and steering clear of swimming in areas where algae or scum may be present along the shoreline.
The GRCA highlighted that blue-green algae thrive on nutrients from fields and lawns that enter local water bodies and reservoirs during heavy rainfall and spring melts, leading to their rapid growth and the formation of blooms or scum on the water’s surface. Certain types of blue-green algae can produce toxins harmful to humans and animals.
The GRCA has informed the Wellington-Dufferin-Guelph Public Health and the Ministry of Environment, Conservation, and Parks about the situation.