Blue-Green Algae Risks Heightened Across Minn.

Updated: 07/15/2013 4:17 PM By: Maricella Miranda

Blue-green algae
Blue-green algae
Photo: Photo courtesy of the MPCA.

Minnesota's recent sunshine and hot weather is making for perfect algal bloom conditions.

The Minnesota Pollution Control Agency is reminding people that some algae can be harmful for pets, livestock - and even humans, the group reported Monday, July 15.

Algae, which is microscopic aquatic plants, are a natural part of the aquatic ecosystem. Most algae is harmless, but certain types can pose health risks.

People and animals might become sick if they touch or ingest affected algae water, the agency stated. In extreme cases, dogs and other animals have died from exposure to toxic blue-green algae.

"High rainfall, which has been common throughout much of Minnesota this spring, results in nutrient-rich runoff entering our lakes, fueling algae growth," said Steve Heiskary, MPCA lakes expert, in the statement. "While spring and early summer temperatures were cooler than normal, lake temperatures have warmed rapidly. Given these conditions, we are likely to see blue-green algae blooms on many of our lakes."

There are many types of blue-green algae. The algae is found throughout Minnesota, but thrive particularly in warm, shallow, nutrient-rich lakes. The algae is often blown toward downwind shorelines, making for perfect conditions for humans and animals to contact it.

Animals that come into contact can show a variety of symptoms, ranging from skin irritation, vomiting, severe disorders like circulatory, nervous and digestive systems and severe skin lesions. In the worst case scenario, animals can suffer convulsions and die.

Humans are rarely affected by toxic algae because algal blooms smell and appear blue-green. Human health effects can include irritation of skin, eyes and nasal passages, as well as nausea and vomiting. Extreme cases can cause paralysis and respiratory failure.

There are no short-term solutions to correct blue-green algal bloom, the agency reported. Once bloom occurs, the only option is to wait for weather changes, such as significant rainfall, wind shifts and cooler temperatures to stop the algae's growth.

Click here for more information about algae and harmful algal blooms.

What is it?

Harmful algal blooms (HAB) are blue-green (cyanobacterial) algal blooms containing toxins or other noxious chemicals, which can pose harmful health risks.

Why is this a concern?

People or animals might develop skin irritation or upper respiratory problems from exposure to HAB, and in extreme cases, dogs and other animals have even died after drinking lake water containing these toxins.

Where is it?

Severe blue-green algal blooms typically occur on lakes with poor water quality (high in nutrients), and look like green paint, pea soup, or a thick green cake (see photo gallery below for examples). HAB often result in extremely low water clarity (less than 1 foot). There is no visual way to predict the toxicity of an algal bloom

What should I do if I find it?

When these conditions are present, people should avoid contact with the water and they should prevent animals from swimming in or drinking the water. Scientists do not yet know what causes some blooms to produce toxins while others do not, so the safest course of action is to avoid contact with all blue-green blooms.

What does it look like?

Blue-green algae can be hard to distinguish from other types of algae. While it's often described as looking like pea soup or spilled green paint, it can take other forms as well. The photos below show some of the diversity of blue-green's appearances and also provides some examples of other types of algae or plants that may be mistaken for blue-green algae.