Contact: Nancy Miller, 507-280-3590
St. Paul, Minn. - Recent severe blooms of blue-green algae on Lake Crystal in Blue Earth County have prompted the Minnesota Pollution Control Agency (MPCA) to recommend that the public and their pets to stay out of the water until the bloom subsides.
Area citizens have reported a definite odor from the lake and clumps of algae are visible on the lake's surface. The Lake Crystal bloom is one of several reported throughout the state. Blue Earth, Wright, McLeod, Kandiyohi and Douglas counties have reported similar blooms on local lakes. One veterinarian-confirmed dog death occurred after contact with Fountain Lake in Wright County. Blue Earth County health officials received a report of a child getting sick after swimming in Lake Crystal. A connection between water contact and the child's illness is under investigation.
Steve Heiskary, a lake expert with the MPCA, says, "You don't have to be an expert to recognize water that might have a toxic algae bloom. If it looks bad and smells bad, it's probably best not to take chances with it."
Algae are microscopic aquatic plants, and are a natural part of any aquatic ecosystem. There are hundreds of species. Under the right conditions, algae populations can "bloom" with dramatic growth, turning the water cloudy and green, a sight familiar to most summertime lake-goers.
Most algae blooms are harmless. But blue-green algae, when present in the water in high concentrations, can produce potent toxins that can affect humans or animals. Blue-green algae are found throughout Minnesota, but thrive particularly in warm, shallow, nutrient-rich lakes.
As algae concentration can vary widely across the lake, so can associated toxins. Often occurring on downwind shorelines, high algal concentrations may produce harmful conditions. It is these near-shore blooms where humans and animals most often come in contact with the blue-green algae and where the risk of toxins is greatest.
Harmful effects on humans are not often reported, probably because the unpleasant appearance and odors of a blue-green 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.
Distinguishing blue-green algae from other types may be difficult for non-experts, but in general, blue-green algae may look like tiny grass clippings or small green irregular blobs in the water. Severe blue-green algae blooms generally look pretty nasty, and are sometimes compared to pea soup, spilled green paint or floating mats of scum. They often smell bad as well. While such conditions would seem to keep most people away, it is surprising how many still will swim or wade in such waters or let their animals enter it.
For more information about toxic algae blooms, go to www.pca.state.mn.us/water/clmp-toxicalgae.html, or call 651-296-6300 or 1-800-657-3864. Photos of the Lake Crystal algae bloom are available upon request.