Nathan Wallick is a firefighter in the American city of Peoria, Illinois. He also likes to use bows and arrows for sport. Now, that sport is helping him make extra money and improve the local environment. People pay Wallick to lead hunts on the Illinois River to kill Asian carp, an invasive fish. Nathan Wallick is one of several private boat operators helping to stop Asian carp from entering Lake Michigan, one of the largest bodies of water in the United States. The hunt takes place in an area of the river about 160 km from Lake Michigan. Wallick’s customers shoot arrows at the carp as the silvery fish jump out of the water behind the boat.