The public is being advised to take precautions as a blue-green algae bloom is affecting Thetis Lake.  

The Capital Regional District (CRD) and Island Health on Monday (July 8) expanded an existing algae advisory in effect for Elk Lake to also cover Thetis Lake. 

Visitors of the regional parks are being encouraged to avoid contact with the algae, which usually produces a visible blue-green sheen, and to keep animals leashed so they don't drink or swim in the lake. The CRD recommends the public follow those precautions until the advisory is listed. 

Algae can appear as surface scum on the lake, but the CRD notes that not all blooms are easy to see and their toxins may still be present even if they're not visible. 

"These algae are known toxin producers. Ingesting water containing these cyanotoxins may cause a range of symptoms, including headaches and abdominal pain in humans, and can lead to lethal liver damage in dogs," the CRD said.

The status of the algae bloom can be followed .