Nick Fetty | July 15, 2015

As temperatures rise algal blooms are popping up in Iowa waterways.

The Iowa Department of Natural Resources has posted advisories cautioning swimmers to stay out of the water at 11 state parks because of harmful algal blooms. Algal blooms are caused by a combination of phosphorus pollution and high temperatures which creates microcystin toxins in the water. When ingested these toxins can cause skin rashes and asthma-like symptoms for humans and potential fatalities for dogs, livestock, and other animals.

A recent blue-green algae breakout on Crystal Lake in north central Iowa has caused a “substantial fish kill” on the 264-acre body of water. Thousands of fish died due to reduced oxygen levels from the algal outbreak. Iowa sees between five and 14 cases of microcystin poisoning each year and an infectious amoeba caused the death of a 14-year old boy swimming in a Minnesota lake earlier this summer.

“The toxins can affect the liver as well as the nervous system. In the most extreme they can cause respiratory distress. Often times we see issues with nausea or diarrhea, headache, that kind of thing,” IOWATER Program Coordinator and Iowa DNR Research Geologist Mary Skopec told Radio Iowa.

Iowa DNR monitors beaches at 39 state parks between Memorial Day and Labor Day. Last summer DNR officials posted advisories at 22 beaches.

Currently the Iowa DNR advises against swimming at 14 beaches: Backbone Beach, Beed’s Lake Beach, Big Creek Beach, Black Hawk Beach, Denison Beach, Emerson Bay Beach, Geode Lake Beach, Lake Darling Beach, Lake MacBride Beach, North Twin Lake Wet Beach, Pine Lake South Beach, Rock Creek Beach, Springbrook Beach, and Union Grove Beach.