Officials warn of blue-green algae outbreak in Wisconsin's Geneva Lake

LAKE GENEVA, Wis. (CBS) -- Anyone heading up to Geneva Lake in Wisconsin should be advised—as state health officials are testing the water for blue-green algae.

The Geneva Lake Environmental Agency , a local organization, first reported on Thursday of last week that a harmful algae bloom had been identified within Geneva Harbor. By Saturday of last week, all Lake Geneva beaches were closed as a precautionary measure.

The Walworth County, Wisconsin Department of Health and Human Services reported as of Tuesday, the City of Lake Geneva's Riviera and Big Foot beaches remained closed, as were the Town of Linn and Linn Pier Road beaches. Two others, Williams Bay and Fontana beaches, closed last weekend, but have since reopened.

Blue-green algae are different from true algae. True algae are eukaryotes—that is, their cells have nuclei. They obtain their energy through photosynthesis—but do not have the roots, leaves, and stems of land plants. True algae are a broad category that covers everything from single-celled diatoms to sea lettuce and giant kelp.

Blue-green algae, however, are bacteria and are also known as cyanobacteria—prokaryotes, with cells that have no nucleus. They still use photosynthesis, but they also produce toxins that can make people and pets sick.

Wildlife in Geneva Lake and the White River have already fallen victim to the blue-green algae bloom, the Geneva Lake Environmental Agency said.

The Wisconsin Department of Health Services advises that water that is discolored or streaky; looks like spilled paint or pea soup; has floating scum, globs, or mats; or has small green dots floating around, should be avoided.

Contaminated lake water should not be swallowed, and no part of the blue-green algae should not be touched.

For pets, the department reminds everyone not to let any animals swim in discolored water where foam, scum, or floating globs of blue-green algae are visible. Pets also should not be allowed to eat or play with blue-green algae globs, or to lick the scum off their fur.

Sources differ on the best advice for fishing. Some say the flesh can still be eaten safely if the fish is cleaned well and gutted—as toxins accumulate in organs such as the liver and gut, However, the Illinois Environmental Protection Agency says since it is not known how much algal toxin can accumulate in fish filets, or muscles, it could be best to wait a week or two until a blue-green algae bloom is gone before fishing.

Further, swimming should be avoided in areas where one's feet are not visible in knee-deep water.

Anyone in the arear around Geneva Lake who suffers symptoms related to blue-green algae exposure—including stomach cramps, diarrhea, vomiting, headaches, fever, muscle weakness, or difficulty breathing should contact the Wisconsin Poison Control Center, at 800-222-1222, right away, the agency said. Rashes and sore throats were also listed as possible symptoms of blue-green algae toxin exposure.