Swimmers and dog owners are being warned about a blue-green algae bloom at Thetis Lake.
A similar warning was issued last week for Elk and Beaver lakes. All three are popular swimming lakes.
The advisory was issued by the Capital Regional District in consultation with Island Heath. Monitoring of the lakes is ongoing.
Blue-green algae — which appear naturally in lakes, ponds and streams — can produce cyanotoxins that can lead to symptoms such as headaches and abdominal pain in people if the affected water is ingested, and can cause fatal liver damage in dogs.
Dog owners are being advised to keep their animals on a leash near the lakes to ensure they don’t swim in or drink the water.
The algae often creates a visible, blue-green sheen that can look like surface scum on the water, but is not always easy to spot, officials said.
Toxins can be still be present if the sheen isn’t visible.
