On a hot morning in Cape Girardeau, two men pulled up nets from a lake in hopes of catching alligator gar, one of the largest and most feared fish species in North America. They’re scientists with the Missouri Department of Conservation, which has spent 12 years trying to restore the alligator gar’s dwindling population in the state. Its numbers in Missouri have fallen partly because the state doesn’t have strong regulations to prevent overfishing of the species. Man-made structures like levees and dams have also separated the Mississippi River from the floodplain. They block the alligator gar from reaching critical habitat, said Solomon David, an aquatic ecologist at Nicholls State University in Louisiana.