Record number of toxic algae warnings issued for Iowa lakes

Iowa has broken the record for toxic algae advisories at state park lakes.

Friday's Department of Natural Resources beach monitoring report listed two exceedances of the health standard for microcystin, a toxin produced by blue-green algae, bringing the seasonal total of advisories to 25, one more than the previous record of 24 established in 2013.

Visitors to state park beaches are increasingly being greeted by such advisories, which instruct visitors to stay out of the water to avoid becoming sick, said Susan Heathcote, water programs director for the Iowa Environmental Council.

'It's likely we'll continue to see additional beach warnings between now and Labor Day, the last week of the DNR beach monitoring program,” she said.

The latest advisories apply to the beaches at Green Valley State Park near Creston in southwest Iowa and at Black Hawk State Park in western Iowa's Sac County. With six exceedances each for the season, those two beaches account for nearly half this season's advisories.

Although blue-green algae flourishes in all parts of the state, according to Iowa State University limnologist John Downing, only one state park lake in Eastern Iowa, Lake Darling in Washington County, has recorded a microcystin advisory this year.

Blue-green algae, which is caused by a combination of high levels of phosphorus pollution and increased temperatures, has long been a major pollutant of Iowa water. In recent years, however, elevated microcystin levels and beach warnings have been on the rise.

Since 2006, the DNR has issued 139 beach warnings for microcystin exceeding 20 micrograms per liter, a level deemed unsafe by the World Health Organization. Nearly two thirds of these warnings have been posted in the past four years.

Warnings have been issued at 23 of the 39 state park beaches monitored by the DNR, and five of the 13 beaches posted this summer - Lake Darling, Pine Lake, Red Haw Lake, Twin Lake West and Springbrook Lake - had their first microcystin toxin warnings posted this year.

Many other public and private beaches not monitored by DNR are also susceptible to blue-green algae blooms, which cause problems other than microcystin ailments.

Most notable, perhaps, are the Lake Erie toxic algae bloom that fouled drinking water last year in Toledo, Ohio, and the Gulf of Mexico dead zone, a 6,474-square-mile area nearly devoid of aquatic life caused by decaying algae, which uses up available oxygen as it decomposes.

Iowa had its own dead zone last month when a sudden die-off of blue-green algae depleted the oxygen in Crystal Lake near Forest City, causing a massive fish kill.

Both the Iowa Environmental Council and the Environmental Working group called Friday for measures to reduce the phosphorus pollution coming from farms, city lawns and urban and industrial wastewater that is feeding the algae.

'Failing to reduce these sources of phosphorus pollution not only puts our health at risk, but also threatens safe drinking water, has negative economic impacts on communities and our quality of life,” Heathcote said.

Anne Weir, an economics analyst with the Environmental Working Group, said laws requiring grass buffers between crop fields and waterways would go a long way toward reducing phosphorus pollution.

Contact with water above the safe threshold can cause breathing problems, upset stomach, skin reactions and even liver damage. Inhaling water droplets containing toxic blue-green algae can cause runny eyes and nose, cough, sore throat, chest pain and asthmalike symptoms.

The Iowa Department of Public Health is adding 'microcystin-toxin poisoning” as a permanent addition to the list of ailments that doctors must report to the state, according to Stuart Schmitz, an environmental toxicologist with the agency.

Iowa typically has about six reported cases per year, he said.