About cyanobacteria
Cyanobacteria are also known as blue-green algae. They're a type of bacteria that occur naturally in fresh and marine bodies of water. There are many types of cyanobacteria, and some can produce harmful toxins called cyanotoxins.
Cyanobacteria can grow quickly in freshwater lakes and rivers under favourable conditions that can include:
- slow moving waters
- higher water temperatures
- an increase of nutrients in the water, such as nitrogen and phosphorus
These conditions can sometimes lead to large cyanobacteria blooms. When a bloom containing toxin-producing cyanobacteria develops, toxins can reach hazardous levels.
If you live near where a bloom was detected or are visiting a lake and notice algae, follow these safety measures:
- Do not use the water. This includes drinking, cooking, bathing, and brushing teeth. Note: Using a private water system or boiling the water will not destroy the toxins.
- Do not swim and avoid water sports where there is harmful algae.
- Limit the amount of fish flesh you eat. Some toxins can build up in fish and shellfish. Do not eat the liver, kidneys and other organs. Be careful not to cut the organs when filleting.
- If skin contact does occur, wash with soap and water or rinse thoroughly with clean water to remove algae.
Guides and Information
- The Government of Canada's guide to cyanobacteria and their toxins
- The Ontario Government's 12-point information page
- The North Bay Parry Sound District Health Unit's page on harmful algae blooms
- The Federation of Ontario Cottage Associations Resource Page
- Algae Quick Guide from the Muskoka Watershed Council