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Swimmers advised to avoid Lower Thetis Lake due to blue-green algae

Visitors to Lower Thetis Lake are advised to keep animals on a leash to prevent them from drinking or swimming in the water until a blue-green algae advisory has been lifted. ADRIAN LAM, TIMES COLONIST

The Capital Regional District is advising swimmers to avoid Lower Thetis Lake and to keep animals from drinking the water after a blue-green algae bloom was detected in Thetis Lake Regional Park.

The advisory was sent out with the assistance of Island Health.

These algae are toxin producers and anyone ingesting water containing the toxins could experience a variety of symptoms, including headaches and abdominal pain in humans and lethal liver damage in dogs.

The CRD has noted the algae usually produce a visible blue-green sheen, which appears as surface scum on the water, but even if it can’t be seen toxins can still be present in the water.

A blue-green algae alert is also active for Prior Lake in the same park. That advisory was issued May 26 and remains in effect.

Updates will be posted at