The Ministry of the Environment Conservation and Parks has found more blue-green algae in the region.
The algae was found on Monday in One Island Lake northwest of Gorham.
BGA are microscopic organisms that are naturally present in lakes and streams.
They are usually present in low numbers but can rapidly increase in warm, and shallow water that gets a lot of sun.
Some blooms produce toxins that pose a health risk to people and animals when consumed, inhaled, or even from skin contact.
Water in the lake should be avoided and you and your pets should not drink it, swim in it, or use it for household purposes.
If you do make contact with a BGA bloom, wash with soap and water and rinse with clean water to remove the algae.
Historically, BGA blooms in the region have been relatively uncommon, but this is the second outbreak in the district this year, with the first occurring on Trout Lake just east of Gorham, and northwest of Thunder Bay.
The Ministry says warmer weather and rising water temperatures may lead to more algae blooms.