Blue-Green Algae Bloom Located in Callander Bay

The Ministry of the Environment, Conservation and Parks (MECP) has confirmed that a sample collected on July 29, 2025, from Callander Bay is indicative of a blue-green algae bloom (also known as cyanobacteria). The Municipality received this confirmation on August 11, 2025.

Blue-green algae can produce toxins that may be harmful to people, pets, and livestock. While the situation is being monitored, we urge everyone to take precautions to stay safe.

What you should do if you think you see a blue-green algal bloom:

- Assume toxins are present—you can’t tell by looking.

- Avoid contact with the bloom; do not bathe or swim in affected water.

- Do not drink untreated lake water.

- Keep pets and livestock away from the shoreline.

- Boiling water won’t help—it can actually increase toxin concentration.

If the water looks clear and there’s no visible bloom, recreational activities like boating and fishing are still safe to enjoy.

For more information:

For health-related information, visit the North Bay Health Unit.

Public Service Announcement from the North Bay Health Unit - Monday, August 11th.

For general information about blue-green algae, visit the MECP website.