dnr-LOGO-thmbThousands of fish have been killed in a southeast Iowa creek and investigators suspect farm chemicals from a crop duster may be the cause of death.

“We’ve got a very strong suspicion at this point that it was probably aerial application,” said Ryan Stouder, an environmental specialist with the Iowa Department of Natural Resources. “The Department of Ag pesticide investigator is pretty confident it is, just off the visual signs of mineral oil in the water.”

Investigators say the “fish kill” is west of Mediapolis, along a five-to-six-mile stretch of Cedar Fork Creek and a short section of Flint Creek. Experts identified dead bass, catfish, crayfish, sunfish and chubs in the stream.

“From minnows all the way up to good-sized catfish,” Stouder said this morning. “We were kind of estimating somewhere in the 3-5 pound catfish range.”

A local resident discovered the dead fish and notified authorities Friday. Stouder says it appears the incident happened as early as Wednesday of last week.

“I don’t know if it was unintentional drift or an emergency dump so they don’t crash the plane, but the fact that there’s five to six miles of dead fish — I’m trying to figure out why,” Stouder said.

Water samples have been collected to determine which chemical killed the fish. Stouder and an investigator from the Iowa Department of Agriculture were heading to the site this morning when Stouder spoke with Radio Iowa.