A bloom of hazardous and potentially-sickening algae has forced the relocation of a popular polar bear dip on Vancouver Island.

Hundreds of people participate in the New Year’s Day dip, traditionally held at Elk/Beaver Lake Regional Park near Victoria, but the 38th annual event was derailed after traces of blue-green algae – commonly known as “pond scum” – were detected in the water earlier this week.

A bulletin issued by the Capital Regional District confirmed its testing on the bloom came back positive for Cyanobacteria, a bacteria that can lead to headaches, fever, diarrhea and vomiting if ingested.

The CRD advises to visitors to stay out of the water until further notice, and warns pet owners to keeps pet leashed to stop them from drinking out of the lakes.

The district says it will continue to work with Island Health to monitor the situation.

The algae bloom appears as a sheath on the water and can easily be spotted from the shore.

The dip is now scheduled to take place at Thetis Lake at 2:30 p.m. on Jan. 1.