Public Advised of Blue-green Algae Health Risks

North Bay, ON – July 4, 2019 – The City of North Bay is advising the public to be aware of the potential health risks posed by blue-green algae found in Lake Nipissing.

According to the North Bay Parry Sound District Health Unit, a harmful algae bloom (cyanobacteria), also known as blue-green algae, has been found in the lake at Marathon Beach in North Bay and Centennial Park Beach in Callander.

The Health Unit says species of the algae capable of producing toxins were confirmed by the laboratory of the Ministry of Environment, Conservation and Parks.  The toxins in harmful algae can irritate the skin and, if swallowed, cause diarrhea and vomiting.

The locations of such algae blooms can change depending on many factors, including size of the lake, wind direction, water flow, and other environmental conditions that cannot be predicted or controlled. As such, the Health Unit says government authorities are unable to determine where and when there are no toxins and is advising users to exercise their judgment. The City has posted caution signs at Marathon Beach advising of the presence of blue-green algae.

If you live near where the bloom was detected or where a bloom is visible, the Health Unit suggests following these safety measures:

  • Do not use the water. This includes drinking, cooking, bathing, and brushing teeth. Note: Using a private water system or boiling the water will not destroy the toxins.
  • Do not swim and avoid water sports where a bloom is present.
  • If skin contact does occur, wash with soap and water then rinse thoroughly with clean water to remove algae.
  • Limit the amount of fish flesh you eat. Some toxins can build up in fish and shellfish. Do not eat the liver, kidneys and other organs. Be careful not to cut the organs when filleting.

You can find out more about harmful algae at or by calling the Health Unit at 705-474-1400, ext. 5400 or 1-800-563-2808.


Gord Young
 Communications Officer
 705 474-0626 ext. 2505