Kevin Wilson, an aquatic ecologist with the National Park Service, right, and Brandon Senger, supervisory fisheries biologist for the Nevada Department of Wildlife, center, prepare their scuba div …

Kevin Wilson, an aquatic ecologist with the National Park Service, right, and Brandon Senger, supervisory fisheries biologist for the Nevada Department of Wildlife, center, prepare their scuba diving gear while Ambre Chaudoin, a biological science technician of fisheries at Death Valley National Park, helps Senger in preparation for a biannual count of the Devils Hole pupfish at Devils Hole in the Ash Meadows National Wildlife Refuge on Saturday, April 7, 2018. Patrick Connolly Las Vegas Review-Journal @PConnPie