Swimmers are urged to keep out of Lower Thetis Lake due to a blue-green algae bloom that may lead to severe health issues, according to the Capital Regional District (CRD).
The CRD issued an advisory on Saturday in consultation with Island Health for the lake, located within Thetis Lake Regional Park, calling the algae “known toxin producers” that may negatively affect the health of both humans and pets.
“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 in a news release.
According to the regional district, the algae usually produce a visible blue-green sheen that appears as surface scum on the water.
“Not all blooms are easy to see, and toxins can still be present in the water even if you cannot see a bloom. Blooms are unpredictable and may occur at any time,” it said.
The CRD is advising park-goers to avoid swimming in Lower Thetis Lake and to keep animals on a leash to prevent them from drinking or swimming in the lake until the advisory is lifted.
Blue-green algae bloom alerts were previously issued and remain in effect for both Prior Lake, located in Thetis Lake Regional Park, and Wrigglesworth Lake, located in Wrigglesworth Lake Regional Park adjacent to Sooke Hills Wilderness Regional Park.
Blue-green algae alert status updates will be posted to the CRD’s website.