Dr. Eilish Cleary says the blooms can be found in lakes and other bodies of water in the summer or early fall.
Cleary says blue-green algae can produce toxins that may cause skin, eye and throat irritation and may lead to more serious health problems if they're consumed.
The Health Department says people should avoid activities such as swimming and water skiing in areas where a blue-green algae bloom is suspected.
People are also warned not to drink water where blue-green algae blooms are found.
The province asks the public to report suspected algae blooms to the nearest regional office of the Environment Department.