The Capital Regional District (CRD) is advising visitors that a blue-green algae bloom has occurred at Lower Thetis Lake in Thetis Lake Regional Park.
This algae produces a visible blue-green sheen on the surface of the water, appearing as surface scum.
However, not all blooms are easy to see and can be unpredictable, occurring at any time.
As a result, the CRD advises visitors to the park to avoid swimming in Lower Thetis Lake and to keep animals from drinking or swimming in the lake until the advisory has been lifted.
Ingesting water containing the toxins present in this algae can cause headaches and abdominal pains in humans and can lead to lethal liver damage in dogs.
In addition to Lower Thetis Lake, there are also blue-green algae bloom warnings for Prior Lake in Thetis Lake Regional Park and Wrigglesworth Lake, located in Wrigglesworth Lake Regional Park adjacent to Sooke Hills Wilderness Regional Park.