Toxic algae growth common in Wisconsin; about 175 waterbodies have high levels of phosphorus

Excessive algae growth like what was found in Lake Erie — which turned Toledo's water toxic — is a common occurrence in Wisconsin, Lee Bergquist reports for the Milwaukee Journal Sentinel. About one-quarter of the state's more than 700 bodies of water "that fail to meet water quality standards do so because of high levels of phosphorus, which is found in sewage, agriculture and runoff from lawns, according to the Wisconsin Department of Natural Resources." (DNR photo: A channel leading to Lake Winnebago. It is pale blue because it is decomposing, while “fresh” blooms that are not breaking down are usually green)

The DNR states on its website that "dozens of waters statewide experience harmful algal blooms fueled by the nutrient, posing a health threat to people, pets and livestock. Over the past 3 years, 98 people have reported health complaints related to such blooms. Recent statewide stream assessment data suggests that thousands of streams may have excess phosphorus levels. In addition to decreasing the dissolved oxygen that fish and other aquatic creatures need to survive, such excess phosphorus causes major changes in lake and stream food webs, which ultimately result in fewer fish and fish predators." 

In mid-June the Department of Natural Resources issued its first advisory of the summer, Bergquist writes. The DNR said blue-green algae containing the toxin microcystin began turning up in Lake Winnebago, which is a source of drinking water for Appleton, Neenah, Menasha and Oshkosh. "The agency's advice to adults: If you're standing knee-deep in water and can't see your feet, stay out; and keep children and pets out of the water, too. The most common reported symptoms are rashes, stomach ailments and respiratory irritation."

"Between 2009 and 2011, Dunn County in northwestern Wisconsin reported 26 cases of algae-related illnesses from a single, problem-plagued lake, Tainter Lake, according to the DNR and Department of Health Services," Bergquist writes. "In Adams County, there were 20 illnesses reported from exposure on the Petenwell Flowage; 12 illnesses in Dane County at Lakes Mendota and Kegonsa, and seven illnesses in Winnebago County on Lake Winnebago." (Read more)