WINNIPEG -- A lake near Kenora is being investigated for a possible blue-green algae bloom.

The Northwestern Health Unit in Ontario said it has received reports of an algae bloom on Granite Lake. The bloom is being tested by the Ministry of Environment, Conservation and Parks to determine if it is blue-green algae, according to a release from the Northwestern Health Unit.

The results are not currently known, so residents and visitors are being asked to treat the algae as if it is blue-green algae.

Blue-green algae, or cyanobacteria, are microscopic organisms that are naturally present in lakes and streams. The algae can rapidly increase in warm, shallow, undisturbed surface water that gets a lot of sun, and can form blooms that discolour the water or produce floating scum on the water’s surface, according to the health unit.

Some blue-green algae produce toxins that can pose a health risk to people or animals if exposed in large amounts if swallowed, if they come into contact with the skin or if airborne drops containing toxins are inhaled while swimming, bathing or showering.

The health unit advises people and pets to not drink the water, and avoid swimming or household use. If contact does occur, wash with soap and water or rinse thoroughly with clean water to remove algae.