Local wildlife experts are saying residents should follow recent warnings from state health officials to watch out for potentially deadly algae blooms.
The blooms, known as cyanobacteria, can grow quickly over the summer months in warm, fresh water, and made worse by nitrogen runoff from fertilized fields. The algae are being credited with dozens of dog deaths around the country, leading to warnings from the Illinois Department of Health and Illinois Environmental Protection Agency to watch for the blooms and avoid any water that seems contaminated.
“These organisms are microscopic. They are not like normal algae ... and they are very, very potent,” said Dr. Michael Biehl, clinical professor of toxicology at the University of Illinois College of Veterinary Medicine. “If dogs get exposed to very much it is usually fatal.”
David Wyffels, a fisheries biologist with the Illinois Department of Natural Resources, spends a lot of  time on area bodies of water. He said the blue-green algal blooms being reported aren’t anything new. They usually occur more frequently when there is a wet spring and a hot, dry summer. The bloom is easy to identify and appears as lime green paint on the water surface.
“It’s not problematic in Henry County,” Wyffels said, but he has seen the bloom in other areas.
He said that not every blue-green algae bloom is toxic, but still cautions people about allowing their dogs to drink or come in contact with water with algae.
“Without testing, we don’t know if it’s toxic or not,” he said, noting the brightly colored blooms will die back in the fall and be gone.
Jolyn Jackson, site superintendent for Johnson-Sauk Trail State Recreation Area, said she received a warning about the potential for algae blooms from the Illinois Department of Natural Resources back in June.
But so far, she said she hasn’t seen any evidence of a bloom on Johnson Lake.
“We haven’t had any issues at our site,” she said.
Although people do allow their dogs to swim in Johnson Lake, Jackson cautions them against doing so.
“Technically it’s really for fishing only,” she said. “Dogs aren’t allowed to swim there.”
Scientists have been studying toxic algae for a long time, according to Biehl. There are actually different types — some produce toxins which attack the liver and cause massive internal bleeding, and some attack the nervous system and paralyze muscles. Toxic algae has been killing mammals in Illinois for years.
“One of the liver toxins was first discovered here (at the University of Illinois),” said Biehl. “A bunch of cattle were found dead around a pond in Decatur. We took samples and that toxin was characterized in the 1980s.”
Large doses of toxic algae kill very quickly. Biehl spoke of a documented case where a dog died and sank while swimming through an algal bloom.
“He was probably consuming it as he was swimming, so he got a pretty good dose,” said Biehl.
He also mentioned a newspaper article about a fish kill on the eastern side of the state that may be related to algae, though the cause is still unknown.
The algae is often present in Illinois lakes in small or moderate amounts, according to the IDPH, but can grow quickly. This sudden, rapid growth is referred to as “bloom.” The bloom appears as “a thick scum layer or green paint on the water and can be a variety of colors, including blue.”  The algal bloom is harmful to both humans, animals and the environment because it produces a toxin that can cause a variety of symptoms, such as  rashes, hives, diarrhea, vomiting, coughing or wheezing. “Ingestion, inhalation, or direct contact with contaminated water may cause illness.”
People coming in contact with the water should rinse off with clean water; wash their hands before eating and anyone exhibiting any symptoms should contact a healthcare provider.
Anyone who suspects a blue-green algal bloom can report it to the IEPA by filling out a form available on its website.
Leslie Renken of the Peoria Journal Star contributed to this report.