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Blue green algae leads to temporary health advisory at Otter Lake Beach

Weekendrainspotentiallyclear hazardousswimmingconditions

By Joseph Back

What do you do when the algae turns blue in your favorite local freshwater swimming hole?

Stay out is a good first response. Coming in Friday from the Chippewa County Health Department was the news that its otherwise regular beach testing had revealed an issue up at Otter Lake—blue/green algae.

“We test 10-12 beaches in the county on a regular basis,” Chippewa County Environmental Health Coordinator Samuel Flatland said. “Last week there was just a little bit of blue-green algae bloom at Otter.”

Known for blooming in times of high temperatures like those of last week, blue-green algae produces a byproduct (called a 'metabolite') which is toxic to humans. Said to have a paint like consistency, it meant getting in the water, was done at one’s own risk.

See HEALTH NOTICE, page 11

A sign at Otter Lake Beach last Thursday. Photo by Joseph Back. HEALTH NOTICE

From Page 3

"CAUTION!" the yellow tape read as the beach was (mostly) empty this past Thursday. "Swim at your own risk.” With long-term analysis from the

Wisconsin Department of Natural Resources and UW-Madison showing Wisconsin to be getting “warmer, wetter, and experiencing a longer growing season,” the possibility of algae blooms and exposure as such is increasing in like manner. Among the symptoms of exposure to toxins produced by bluegreen algae are headache and numbness, Parasthesia, irritation of the ears, nose or throat, skin irritation or rash, nausea, vomiting and diarrhea, as well as cardiac, respiratory, and liver failure, though the last three are considered rare. If you think you are experiencing symptoms from exposure to blue green algae and like blooms, contact with a doctor on the Poison Information Hotline at 800-222-1222 should be made right away. The probability of adverse health euects increases with exposure to the toxin microcystin produced by the blue green algae and cyanobacteria involved, measured in micrograms per liter. Low risk is less than 10 micrograms per liter, increases to moderate between 10 and 20 micrograms per liter, thence to high with 20 to 2,000 micrograms per liter, and becomes very high with exposure more than 2,000 per microliter. Cell density of blue green algae is tied in with these numbers.

As to Otter Lake Beach, meanwhile, the signs could come down soon, pending confirmation of the blue green algae departure with weekend rains.

"As long as it's confirmed to be gone, it should be safe to swim in the area,” Flatland said of blue green algae and beach safety. The best way to find that out, is paying attention to the sign, located up at Otter Lake on the left side as one enters the beach area.

An example of hazardous water conditions from blue-green algae. Image from Chippewa County Department of Health.

July 27, 2022