Algae blooms pose danger to dogs and swimmersWhen the summer sun shines and temperatures climb, conditions are ripe for Minnesota lakes to produce harmful algal blooms.
When the summer sun shines and temperatures climb, conditions are ripe for Minnesota lakes to produce harmful algal blooms.
The Minnesota Pollution Control Agency (MPCA) is again reminding people that some blue-green algae can harm pets, livestock and even people.
Algae are microscopic aquatic plants and are a natural part of any aquatic ecosystem. Under the right conditions, some forms of algae can become harmful.
Blue-green (cyanobacterial) algal blooms contain toxins or other noxious chemicals that can pose harmful health risks. People or animals may become sick if exposed to these blooms.
In extreme cases, dogs and other animals have died after exposure to lake water containing these toxins.
“High rainfall resulting in nutrient-rich runoff entering our lakes fuels the growth of algae. As sunlight increases and temperatures warm, we can anticipate blooms of blue-green algae on many of our lakes,” said MPCA lakes expert Steve Heiskary.
Heiskary is a member of an interagency work group that’s spreading the word that blue-green algae should be avoided.
“When in doubt, best keep out,” advises a poster the group has distributed around the state.
Blue-green algae are found throughout Minnesota, but thrive particularly in warm, shallow, nutrient-rich lakes. Often occurring on downwind shorelines, it is in these blooms that humans and animals most often come in contact with blue-green algae and where the risk of algal toxins is greatest.
There is no visual way to predict the toxicity of an algal bloom and distinguishing blue-green algae from other types may be difficult for non-experts. But harmful blooms are sometimes said to look like pea soup, green paint or floating mats of scum.
They often smell bad as well.
“You don’t have to be an expert to recognize water that might have a harmful algae bloom,” Heiskary said. “If it looks bad and smells bad, it’s probably best not to take chances with it.”
Humans are not affected very often, probably because the unpleasant appearance and odors of a blue-green algal bloom tend to keep people out of the water. But human health effects can include irritation of skin, eyes and nasal passages, and nausea and vomiting. Extreme cases can produce paralysis and respiratory failure.
An animal that has ingested toxins from an algae bloom can show a variety of symptoms, ranging from skin irritation or vomiting, severe disorders involving the circulatory, nervous and digestive systems, and severe skin lesions. In worst cases, the animal may suffer convulsions and die.
These factors make it important to take a preventative approach to dealing with potential harmful algal blooms.
There are currently no short-term solutions to correct a blue-green algal bloom. Once a bloom occurs, the only option available is to wait for weather changes, such as significant rainfall, wind shifts or cooler temperatures, to disrupt the algae’s growth.
The key to solving algae problems long-term is to improve water quality by decreasing the amount of nutrients that runoff carries into lakes.
For more information about harmful algae blooms, go to www.pca.state.mn.us/water/clmp-toxicalgae.html or call (651) 296-6300 or 1-800-657-3864.