What You Should Know About Blue-Green Algae

Being known as the “Land of 10,000 Lakes,” it’s no surprise that Minnesotans love to spend time in the water. And with so many lakes to choose from, it’s important to know the basics about blue-green algae to keep our dogs and selves safe during warmer months.

Wagging Tails dog swimming in lakeVarious types of algae are common in lakes throughout Minnesota and are usually harmless, but under certain conditions “blue-green” algae can form. This is a potentially dangerous type of algae that can cause illness and death in both animals and humans. Thriving in warm, shallow, nutrient-rich lakes, blue-green algae can be present throughout the year but will not cause health problems until an extensive “bloom” occurs. Blooms take place when the blue-green algae become so numerous, they dominate the other algae in the lake. When a bloom is present, the appearance and odor of a lake changes and can take on the look of pea soup, spilled green paint or smell swampy. Sometimes a bloom can be more subtle and the water will become very cloudy with a green, yellow or blue-green tinge.

Toxic blue-green algae blooms are most common in late summer and early fall with lakes in central and southern Minnesota making especially hospitable environments. In order for blue-green algae blooms to occur, a combination of factors must be present: warm temperatures, lots of sunlight, and excessive nutrients. Excessive nutrients in lake water are largely the result of water runoff from urban areas and agricultural land – many communities are now taking action to minimize water runoff in efforts to reduce blue-green algae blooms in urban lakes.

Unfortunately, the first sign of a blue-green algae bloom is often a sick dog that was swimming in the effected lake. Symptoms of blue-green algae exposure can vary from skin irritation, legions and vomiting to circulatory, nervous and digestive system disorders. Blue-green algae can be fatal to animals so it is important to seek veterinary attention if you think your dog has come in contact with an algae bloom. If contact has occurred, wash your dog’s coat immediately to eliminate additional exposure through self-grooming. And if you have doubts about the safety of a lake, stay out of the water and contact Minnesota Pollution Control at 651-757-2419.