The Simcoe Muskoka District Health Unit (SMDHU) has issued a warning for residents in the Lake Rosseau area after blue-green algae was found in Three Mile Lake and the Clark Falls.
According to the health unit, some varieties of blue-green algae are capable of producing toxins that can be harmful to humans and animals.
The SMDHU received notice from the Ministry of the Environment, Conservation and Parks on Friday that laboratory tests confirmed the presence of the harmful algae.
The health unit is cautioning residents that exposure to blue-green algae, whether by drinking, swimming, bathing, cooking, or through eating fish caught from the lake, can result in illness. According to health officials, boiling the water will not destroy the toxins and home treatment systems should not be relied on.
According to the health unit, symptoms from consuming algae toxins can include headaches, fever, diarrhea, abdominal pain, nausea and vomiting. However, symptoms can be more serious if large quantities of water are swallowed.
The health unit says officials will continue to monitor both lakes.