LCHD: Be on the lookout for blue-green algae this summer

For the Tomahawk Leader

LINCOLN COUNTY – Summer is here, and the Lincoln County Health Department (LCHD) is reminding the public to be on the lookout for blue-green algae when enjoying the area’s waterways.

“Although warmer temperatures and sunshine are welcomed, this weather creates the perfect conditions for algal blooms to develop, some of which can be harmful to humans and pets when swallowed, touched or inhaled,” LCHD stated.

LCHD said that although many species of algae are found in local lakes and rivers and are a vital part of waterways, blue-green algae are not true algae, but are actually bacteria known as cyanobacteria.

According to Mike Mandli, LCHD Environmental Health Specialist, risk for blue-green algae increases after heavy rain, causing agricultural and residential fertilizers to run off into area waterways.

“These added nutrients to our water, combined with little wind, warm temperatures and sunlight, can create ideal conditions for blue-green algae to grow,” Mandli explained. “If it looks like split pea soup, it is important to stay out.”

Mandli noted that these conditions typically occur in Lincoln County from mid-June through mid-September.

Blue-green algae’s color is often described as pea soup or spilled green paint, but it can also be other colors, including white, red or brown. Blue-green algae grows most abundantly in warm, calm, sunny weather with water temperatures above 75 degrees Fahrenheit.

“When conditions are just right, blue-green algae can grow quickly and create blooms,” LCHD said. “Blooms may produce a bad odor. It can be difficult to tell whether an algae bloom is dangerous or not, so it is best to treat all algae as dangerous and when in doubt, stay out.”

Blue-green algae’s color is often described as pea soup or spilled green paint, but it can also be other colors, including white, red or brown. Photo courtesy of Wisconsin DNR.

Upon arriving to a beach or body of water, LCHD suggests looking for postings and water quality notices and doing a visual inspection of the water to look for any signs of blue-green algae before entering the water.

LCHD also provided the following recommendations:

  • Do not swim or wade through algal scum.
  • Do not boat, water ski or jet ski through algal blooms.
  • Do not fish in lakes where algal scum is present.
  • Always shower off with soap and water after swimming in a lake.

LCHD recommends contacting a healthcare provider if an individual is exposed to blue-green algae and is experiencing the following symptoms:

  • Sore throat
  • Red skin
  • Runny nose
  • Hives
  • Cough
  • Earache
  • Difficulty breathing
  • Headache
  • Itchy eyes
  • Stomach pain
  • Itchy skin
  • Vomiting

“Pets are especially susceptible to blue-green algae because they can’t tell if water is unsafe,” LCHD stated. “Because of their relatively small size, animals do not need to swallow very much contaminated water to become ill. If you think you or your pet may have come into contact with any blue-green algae, rinse them off right away, do not let them lick the algae off and contact a veterinarian right away.”

For more information on blue-green algae, visit the Wisconsin Department of Health Services (DHS) website at

For information on reporting a  blue-green algae bloom to the Wisconsin Department of Natural Resources (DNR), how to protect children and pets and links for DNR beach closings and advisories, visit

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