(AP) — This June 13, 2012, photo shows an Asian carp, jolted by an electric current from a research boat, jumping from the Illinois River near Havana, Ill.
Scientists at a network of field stations on the Mississippi and Illinois rivers are using electric currents to stun fish so they can be scooped up and examined. Researchers have been monitoring fish populations on the rivers for many years and now are looking for evidence that native species are being affected by the arrival of invasive Asian carp. (AP Photo/John Flesher)