Experts from the Iowa Department of Natural Resources have been working fish kills in central and southeast Iowa. D-N-R spokesman Kevin Baskins says one kill involved about 600 fish in School Creek east of Iowa Falls.

Baskins says a private contractor was applying wastewater to land from a nearby biodiesel plant and some of the water got into a tile and then the creek. He says the material in the wastewater used up the oxygen in the water needed by the fish.

The wastewater came from the biodiesel plant operated by Cargill in Iowa Falls, and Baskins says they don’t know yet if the company will face any charges. He says some samples have been sent to the state hygienic lab and once those samples are processed, the D-N-R will determine whether they’ll file any charges.

Baskins says normally the wastewater is applied to fields and breaks down naturally without any problems. Baskins says this plant is relatively new, and he says some plants pre-treat the water at their own plant and then send the rest to the city wastewater plant. Baskins says that’s an option this company can look at to avoid any future problems. The other fish kill happened along 50 miles of the Des Moines River in southeast Iowa.

Baskins says the kill was between Ottumwa and Bonaparte in Van Buren County and involved up to one thousand shovelnose sturgeon. He says there were not any other species found in the kill. Baskins says the nature of the kill makes investigators think this might be a natural kill.

Baskins says when they see fish kills involving one species of fish, that indicates a natural kill from something like a disease. He says a kill caused by pollution is indiscriminate, and they’ll see more species of dead fish. Baskins says they’re running some tests to find out what may’ve cause the kill.

Baskins says samples have been sent to a national lab in Wisconsin that specializes in fish kills. Baskins says the shovelnose sturgeon is a prehistoric type species that can grow to be three feet long. He says some of the dead fish measured nearly 30 inches.