Later today, the Illinois Department of Natural Resources will attempt its second massive Asian carp kill, dumping 2,000 gallons of a toxic chemical into a two-mile stretch of the Little Calumet River in Chicago's southern suburbs. Officials hope the operation will help them understand how many carp are in the area.

UPDATE (11:52 a.m.): Environmentalists across the state are praising this week's chemical operation, organized jointly by Illinois and federal officials. Still, they suggest more emphasis should be placed on crafting a permanent solution that will create a physical barrier blocking invasive species from entering the Great Lakes. From a press release:

“We cannot afford to be focused only on carp,” said Henry Henderson, Director of the Midwest Program for the Natural Resources Defense Council. “The Chicago Waterway system is a highway for invasive species moving in both directions, and most of these critters cannot be stopped with nets or even an electric fence. Since we cannot keep poisoning our waterways, it is time to move on to a real solution to this vexing issue – a physical barrier separating the Great Lakes from the Mississippi River system.”