Yahara River CREDIT: Marion Stuenkel
MADISON (WKOW) -- Madisonians could see it span across the surface of the water. A giant blue-green algae bloom covered wide areas on the southern shore of Lake Mendota and the Yahara River on Friday afternoon. It shocked several people out on the lake and walking around it. Officials are now warning the public that the algae is highly toxic.
It was as white as ice and fluffy looking as it floated down the water.
"I've never seen it this bad," said David Wallner as he biked through Tenney Park along the Yahara River.
"It's really horrifying to look at. I mean, it looks like something that's come out of a washing machine. The suds and the color," he said as he described what he saw.
The widespread scene also came as a shock to Clean Lakes Alliance Spokesman Adam Sodersten. He said the gunk stretched the entire length of downtown Madison.
"It goes just past the Memorial Union, all the way down to where we are at Tenney Park and a little bit around towards Maple Bluff. It's this southern shore that's blocked from the wind," Sodersten said.
He said it's caused by both Mother Nature and Madisonians. It's produced from the amount of phosphorus that enters the water from runoffs. Then, the recent rain and hot temperatures with low wind help create the perfect storm to make the algae.
"Just one pound of phosphorus in runoff can produce 500 pounds of algae," Sodersten said.
Officials are warning the blue-green algae is dangerous.
"You can get sick if you swim in it, if it gets into your eyes, nose or ears. And the same with pets. When you see these blue-green algae blooms, be sure to keep your pets out of the water," Sodersten said.
On Friday evening, it wasn't stopping several fishermen and a kayaker. But it could affect your weekend plans. Sodersten said there isn't a definite time in which the algae will be gone.
"It all depends on weather conditions. Now, if the winds pick up and we have a storm tonight like some meteorologists are predicting, it could be gone tomorrow," he said.
As of Friday night, "The Department of Public Health has closed Tenney Park Beach, James Madison Beach and the Union Pier because it's toxic," Sodersten said.
For more on this story: http://www.wkow.com/story/35686265/2017/06/16/toxic-blue-green-algae-bloom-stretches-across-lake-mendota-yahara-river