RESOLVED: Blue-Green Algae at Lower Thetis Lake

May 26, 2022 (updated Jan 20, 2023, 3:01pm)

As of Jan 20, the advisory has been lifted at Lower Thetis Lake. However, blue-green algae blooms are unpredictable and may occur at any time.

The blue-green algae advisory is now lifted for Lower Thetis Lake, located within Thetis Lake Regional Park. Water samples collected indicated a “below detection limit” result for cyanotoxins. The extended absence of blue-green scum combined with test results are good indicators that the bloom is over. 

Park users are reminded to watch for the distinctive blue-green sheen that can appear on the lake surface at any time. These blue-green algae are known toxin producers. Ingesting water containing the blue-green algae may cause a range of symptoms, including headaches and abdominal pain in humans, and can lead to lethal liver damage in dogs.

Please visit www.crd.bc.ca/alerts and Twitter @crd_bc for updates on active alerts. To learn more about blue-green algae visit our website