The Minnesota Pollution Control Agency says the recent stretch of warm, calm weather has brought good conditions for blue-green algae in lakes.
The St. Cloud Times reports this year the heavy rains in May and June washed a large amount of nutrients into Minnesota lakes and streams. Those nutrients, including phosphorus, help feed the algae growth.
Steve Heiskary, lake expert with the Minnesota Pollution Control Agency, says warm, sunny weather allows for the blue-green blooms to take off.
Blue-green algae blooms are thick and cloudy, and can look like green paint or floating mats of scum. Some contain toxins that can be deadly to dogs and other animals. In humans, they can cause nausea and irritation of the skin, eye, nose and throat.