RATHBUN LAKE — The algal bloom that's turned much of the Rathbun Lake water green is toxic, the U.S. Army Corps of Engineers confirmed Friday afternoon.
Samples collected at various sites from the Buck Creek and Island View beaches returned positive tests for algal toxin microcystin above the state's advisory threshold of 20 micrograms per liter.
Microcystin is released by some species of blue-green algae and can affect the liver, according to information from the Iowa Department of Public Health. People can become sick from the toxins by contacting the bloom or wallowing water while swimming, or by breathing airborne droplets containing the toxins during boating or waterskiing.
Pets and other animals that drink from the water's edge can be exposed to deadly levels of the toxin. Pets can also get sick by swimming in water where algal blooms have been and then licking themselves after leaving the water, according to the health department.
Symptoms of microcystin poisoning include breathing problems, upset stomach, skin reactions and liver damage. Symptoms can take hours or days to show up but normally show within a week of exposure, according to the health department.
Public health officials say those who come in contact with the algae should wash off with fresh water and soap, avoid drinking alcohol, do not use acetaminophen, and check with a doctor if experiencing symptoms and mention the exposure.
The Island View and Buck Creek beaches remain closed. The aquapark at Honey Creek Resort also announced it would temporarily close due to the test results. Marinas, lakeside businesses and park camping facilities remain open, the Corps of Engineers reported.
Algae has been present in several areas of the lake, according to the Corps. Those areas include near the dam, upper lakes areas and Corps of Engineer's beaches and boat ramps. Algal blooms can develop and move quickly. The Corps of Engineers advised avoiding areas with a scummy, paint-like surface or where the water is bright green.