Scuba Divers Conduct Pupfish Research (IMAGE) University of Nevada, Reno Caption Scuba divers conduct fish research at Devils Hole, an isolated geothermal water-filled limestone cavern in the Nevada desert. The aquifer-fed pool in the Ash Meadows National Wildlife Refuge, a detached unit of Death Valley National Park, is the habitat for the only naturally occurring population of the endangered fish. It is an extreme environment, with water temperatures and dissolved oxygen concentrations near their lethal limits for fish. Credit Photo by Scott Tyler, University of Nevada, Reno. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.