Frequently asked questions
What are cyanobacteria?
They are bacteria, invisible to the naked eye, with the same green and/or blue pigments as plants and algae. Like them, their pigments allow them to produce energy from sunlight.
Why are they toxic?
Cyanobacteria produce toxins, which are released in the water when they break up. These toxins can cause irreversible damage to the liver and neurological system when they are ingested by humans and animals. They can also cause skin eruptions (red patches) for swimmers.
When are they toxic?
Cyanobacteria have always been found in bodies of water. Most of the time, they are not visible to the naked eye. When they multiply they begin to coalesce and form a scum which can be seen on the surface of the water. It is only when the cyanobacteria are visible that the concentration of toxins is dangerous for human health.
If I boil the water, will that make it safe?
No! Boiling water does not get rid of the toxins. Because they have no taste or smell, and their appearance does not help us detect whether there are toxins in the water, it is better not to consume water or use water when there is an algae bloom present. It is best not to use contaminated water to wash clothes or dishes or for baths or showers. Any contact with the algae may cause skin irritations and skin eruptions. The MDDEP recommends that we eat fish that has been in contact with the cyanobacteria bloom in moderation, and recommends that we not eat the visceral organs.
Why do cyanobacteria occur in lakes?
A number of factors promote the proliferation of cyanobacteria. In our region’s lakes, the main culprit is phosphorus. Phosphorus comes into the lake from a variety of sources: fertilizers, pesticides, waste water, sediments, non-complying septic tanks, etc.
How do they spread?
Cyanobacteria do not spread from one lake to another like the zebra mussel. The fact that you washed your boat is not related to the spread of cyanobacteria. Cyanobacteria are always present in water, and as long as they cannot be seen, they do not pose a problem. It is when all the conditions come together: (food, sun, heat) that they begin to multiply quickly and burst into bloom.
Where can we find out if swimming is banned?
- If the cyanobacteria are visible in the water, avoid any contact with the water
- Ask the lifeguards and look for notices at public beaches
- Call your municipality
- The MDDEP’s regional list of sites where warnings and public health notices about the lakes and rivers affected by blue-green algae in 2007 are posted:
To call to report a sighting of bloom:
- Call the regional office of the MDDEP at: 819-820-3882
- In the evening and on the weekend: Urgence environnement (the environment emergency line): 1-866-694-5454