Algae bloom detected in McGregor Creek

The algae-green waters of McGregor Creek, as seen looking east from the bridge on William Street in Chatham.

It’s August in Chatham-Kent, and that means it’s generally time for wasps and algae blooms.

CK Public Health reports a blue-green algae bloom began recently on McGregor Creek in Chatham, and expanded into the Thames River.

The Ontario Ministry of the Environment, Conservation, and Parks conducted an investigation and collected samples of the affected water.

Those results confirm the presence of the algae.

Blue-green algae (also called Cyanobacteria) are microscopic plants that live in freshwater. Normally, blue-green algae are barely visible, but during warm weather, the algae can rapidly grow to form a large mass called a bloom, giving water a green appearance. 

Further analysis of water samples from McGregor Creek has revealed low levels of harmful toxins.
Nutrients such as phosphorous and nitrogen contribute to the growth of blue-green algae.

CK Public Health’s Joshua Standel said the specific source of nitrogen and/or phosphorus has not been identified. 

He added that typically algae blooms are attributed to surface water runoff, so farming, detergents containing phosphorus and other commercial operations could all be contributing factors.

Household fertilizer runoff, faulty septic systems, and improper waste management systems can also contribute to increased levels of phosphorous and nitrogen in local fresh water.

Toxins that may be present in blue-green algae blooms can have adverse health impacts. Potential health effects could be itchy, irritated eyes and itchy skin that result from direct contact such as swimming. 

If water is swallowed, symptoms such as headaches, fever, diarrhea, abdominal pain, nausea, and vomiting are possible. 

Laboratory analysis to determine whether toxins are present in significant levels is underway.

To protect yourself, Public Health officials advise you avoid activities that increase the chance of exposure to these algae blooms:

  • Do not drink, bathe, or shower in untreated surface water;
  • Do not allow children, pets, or livestock to drink or swim in the water;
  • Do not cook with or boil the water. This may release more toxins into the water;
  • Be cautious about eating fish caught where blue-green algae blooms occur, and do not eat the liver, kidneys, or other organs;
  • Do not treat the water with a disinfectant like chlorine (bleach). This may release more toxins into the water.

 The situation is being monitored, and at this time, drinking water and public beaches are not affected in Chatham-Kent.

Contact CK Public Health at 519-355-1071 or visit the Ontario Ministry of the Environment, Conservation, and Parks for more information.

The water is almost as green as the nearby foliage.


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