Blue-green algae (cyanobacteria) are a common seasonal occurrence in our waterways. These bacteria occur worldwide and some species produce toxins that can affect animals and humans.
Blue-green algae thrive in warm, shallow, undisturbed water that receives a lot of sunlight and that is rich in phosphorus and nitrogen. Animal and human waste and fertilizers contain phosphorus and nitrogen.
Some common ways for phosphorus and nitrogen to enter lakes and streams are from agricultural and lawn runoff and improperly located septic systems.
Toxins can irritate the skin, and if ingested, can cause diarrhoea and vomiting. At high enough levels, the toxins may cause liver and nervous system damage.
Kingston, Frontenac and Lennox & Addington Public Health reminds people using lakes and rivers to watch for algae blooms. Dense blue-green algae blooms may make the water look like pea soup, and can be shades of blue, blue-green, yellow, brown, or red. When a bloom is very large, algae may form solid-looking clumps. Fresh blooms often smell like newly mown grass; older blooms smell like rotting garbage.
If blooms are visible:
- Avoid using the water for drinking, food preparation, bathing, or showering.
- Do not allow children, pets, or livestock to swim in the water or drink the water.
- If skin contact does occur, wash with soap and water or rinse thoroughly with clean water to remove the algae.
- Residents should not boil the water. Boiling will not remove the toxins and it may release more of the toxin into the water.
- Residents should avoid cooking with the water because food may absorb toxins from the water during cooking.
- Residents should not rely on water jug filtration systems as they do not protect against the toxins.
- Do not treat the water with a disinfectant such as chlorine bleach. This may break open algae cells and release toxins into the water.
Residents should be cautious about eating fish caught in water where blue-green algae blooms occur. Residents should not eat the liver, kidneys, or other organs of fish caught in the water. On lakes and rivers where blue-green algae blooms are present, people who use the surface water for their private drinking water supply may wish to consider an alternate, protected source of water.
Media Contact Information: Kingston, Frontenac and Lennox & Addington Public Health at 613-549- 1232, ext. 1248, toll free 1-800-267-7875.