New blue-green algae bloom confirmed in Muskoka lake

Published: September 21, 2018

blue-green algae on the surface of lake water Photo by palickam/Shutterstock

According to new information released by the Simcoe Muskoka District Health Unit, testing has confirmed the presence of a blue-green algae bloom in the southwest bays of Leonard Lake, Ont. This is the sixth confirmed bloom in the area this year.

Blue-green algae blooms are organisms that naturally occur in water bodies when excess nutrients (primarily phosphorous and nitrogen) get into the water. They aren’t always visible, but larger chunks will make the water appear bluish-green, or make the surface look like green pea soup or turquoise paint. Agricultural runoff is a common culprit, but fertilizers and faulty septic systems are more often the cause in cottage country areas. Contaminated water can make humans sick if ingested and can be dangerous if consumed in large amounts. Blue-green algae is particularly toxic for aquatic wildlife, as the blooms deplete oxygen levels in the water.

Those who draw water from the lake are being advised not to drink it or use it to prepare food, as even built-in water filtration systems or boiling the water won’t kill the toxins—in fact, it can make them worse. Locals should also avoid swimming in areas where the algae is present and be cautious when eating fish caught in the lake. Anyone who comes into contact with blue-green algae should rinse with clean, fresh water or wash throughly with soap and water away from the lake.

While blue-green algae blooms aren’t new, they’re becoming more frequent as cottage-country areas grow. Communities are still navigating how to educate cottagers on their ecological impact. Some municipalities, for instance, have replaced older septic systems or banned certain fertilizers, both of which can affect a lake’s ecology.

Cottagers can do their part by being mindful of their environmental impact. Maintaining a natural shoreline is one easy way to prevent excess nutrients from getting into your lake (hey, less work for you). Other tips include avoiding lawn fertilizers, routinely checking your septic system, and using phosphate-free cleaning products. Small changes now can ensure that your lake will be in tip-top shape for summers to come. After all, what would your special place at the lake be without the lake?

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