The Capital Regional District (CRD), in consultation with Island Health, issued an advisory Tuesday (Nov. 7) that there is a blue-green algae bloom on Thetis Lake in Thetis Lake Regional Park.
This advisory is in addition to an existing advisory that is still in effect for Elk Lake in Elk/Beaver Lake Regional Park, the CRD said in a statement.
“Blue-green algae can produce cyanotoxins,” the statement said. “Visitors are advised to avoid swimming in Thetis Lake and to keep animals on leashes to prevent them from drinking or swimming in the lake until the advisory is lifted. The algae usually produce a visible blue-green sheen that appears as surface scum on the water. Not all blooms are easily visible, and toxins may be present in the water even if you cannot see a bloom. Blooms are unpredictable and can occur at any time.
These algae are known toxin producers, the CRD said, and ingesting water containing these cyanotoxins can cause a range of symptoms, including headaches and abdominal pain in humans, and can lead to fatal liver damage in dogs.
