Blue-green algae are naturally present in lakes and streams. They are usually present in low numbers but can rapidly increase in warm, shallow, undisturbed surface water that gets a lot of sun. (Simcoe Muskoka District Health Unit)
One key contributing factor to the growth of blue-green algae is the amount of available nutrients such as phosphorus and nitrogen. Blooms can be caused by agricultural and storm-water runoff as well as leaching from septic systems. (Government of Ontario)
Your health may be impacted when surface scum or water containing high levels of blue-green algal toxins are swallowed, come into contact with the skin, or when airborne drops containing toxins are inhaled while swimming, bathing, or showering. (Simcoe Muskoka District Health Unit)
If you suspect a blue-green algal bloom (refer to Algae Quick Guide, below), it can be reported by calling 1.866.MOETIPS (1.866.663.8477)