Blue-green Algae – Know it and report it

Though more prevalent in the late summer and Fall, under the right conditions Ontario lakes can present with blue-green algae blooms throughout the ice-off season. Therefore it is important to protect yourselves and others from this toxic algae by understanding what to look for and how to report it.

Remember to report suspected sightings by calling the Spills Action Centre1-800-268-6060

The Ministry of the Environment and Climate Change (MOECC) has launched a website page dedicated to identifying blue-green algae. Regionally, the Simcoe Muskoka District Health Unit posts local information here.

Recent News:

April 18, 2022 – Could blue-green algae on Muskoka’s lakes be tied to climate change? – pristine lakes with low phosphorus levels are raising red flags for environmental scientists (

July 8, 2021 – Michigan Researchers find relationship between invasive zebra mussels, toxic algae (Great Lakes Echo)

April 7, 2021 – Dangerous Algal Toxin Named ‘Very Fast Death Factor’ Now Also Found in Air (The Science Times)

March 10, 2021 – Podcast: Core Ideas – A Paleolimnology Podcast “Cyanobacteria Blooms: A Hot Mess” – with Dr. Liz Favot

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Earlier News:

October 6, 2020 – Blue-green algae confirmed in Safety Bay, Lake of the Woods  (TBnewswatch)

September 1, 2018 – Hot summer resulted in blue-green algal blooms on Ontario lakes
Water temperatures appear to have had bigger effect than previously thought

June, 2018 – read this Water Canada article on Duke University study suggesting that nanoparticles + nutrients = algae

March 23, 2017 – IJC’s Heath Professionals Advisory Board Recommends Actions to Reduce Risks from Cyanobacterial Harmful Algal Blooms

August 29, 2016 – Poisonous Algae Blooms Threaten People, Ecosystems Across U.S. (NPR)

August 18, 2016 – ‘We know what to do’: Scientist publishes study on blue-green algae; urges Alberta government to act (Global News)

August 05, 2016 – Numerous long-term studies of lake ecosystems in Europe and North America show that controlling algal blooms and other symptoms of eutrophication depends on reducing inputs of a single nutrient: phosphorus  (Adam Hinterthuer / American Chemical Society)

June 22, 2016 – the U.S. Centers for Disease Control and Prevention (CDC) has launched a new website: Harmful Algal Bloom-Associated Illnesses

May 10, 2016 – “My lake is showing signs of algal blooms. What can I do?”  from the IISD (ELA) blog

November 24, 2015 – Phoslock no quick fix for algae problems in Simon Lake (CBC Sudbury)

Michelle LewinBlue-green Algae – Know it and report it