Dying carp a mystery in Lake Zurich
Lake Zurich village officials and lake property owners are scratching their heads over hundreds of dead carp washing up on shore in the past two weeks.
The dead fish started surfacing in Lake Zurich around July 2.
Lake County health officials say the fish don't pose a health risk but advise people against catching or eating them.
"Some of these fish are not dead yet. Discard the carcasses before they start to decompose," said Mike Adam, senior biologist for the Lake County Health Department's Lakes Management Unit.
Health officials suspect the fish died due to a bacterial infection that is not harmful to humans.
"Of course, you don't want to swim next to decomposing fish," said Dave Heyden, Lake Zurich public works director.
The Illinois Department of Natural Resources this week sent live carp samples from the lake to a federal laboratory in Wisconsin for testing to determine what caused the die-off. The test results won't be in until August.
"We know that it's not related to aquatic weed management because we haven't had a treatment of aquatic weed in three months," said Rich Sustich, president of the Lake Zurich Lake Property Owners Association. "There is no evidence anywhere in the watershed of any chemical contamination. The most likely cause at this point is a bacterial infection of some kind because it's specific only to carp."
Sustich said lake property owners have been asked to clean up the dead fish from their properties along the shoreline.
Village officials also have been picking up dead fish washed up near the lakefront promenade and along the shores of Paulus Park and Breezewald Park beaches.
Fish-kills are not uncommon. Hundreds of crappies and carp started dying off in June at several Lake County lakes, as well as at lakes in other counties.
"Fish-kills are kind of a normal part of the lake ecosystem," Adam said. "We see this in the spring usually after fish get done spawning. They are more prone to disease, sickness."
The health department continues to sample Lake Zurich's beaches twice a week for potential human pathogens.
"The sampling done thus far has not indicated any problem," Sustich said.