A water sample taken Monday has confirmed the presence of blue-green algae in Surprise Lake.

It consists of microscopic organisms which are naturally present in lakes and streams, according the the Thunder Bay District Health Unit, normally in low numbers.

However when warm, shallow, surface water gets a lot of sun those numbers can rapidly increase, often forming blooms which make the water appear like green pea soup or turquoise paint.

Those blooms, when large enough, can form clumps at the surface and can produce toxins which are harmful to both humans and animals if ingested, inhaled or even when it comes into contact with skin.

If you make contact with a bloom wash with soap and water and rinse with clean water to remove the algae.

The TBDHU says blue-green algae blooms in the area have been relatively uncommon historically, but with rising temperatures both in the climate and water, they can become more common.

If you spot a suspected blue-green algae bloom, report it to the Spills Action Centre at 1-800-268-6060.