[MUSIC] Just outside of Death Valley National Park is a place called Devil's hole. Devil's hole is a deep geothermal pool that's home to a very unique species that also happens to be endangered. Devil's hole became part of the park's system in 1952 by proclammation by President Harry Truman and it was due to Both the ecosystem and also because of a peculiar race of fish. And that's a Devils Hole pupfish. Devils Hole pupfish are one of several species of pupfish. When water levels dropped during the last ice age these pupfish were separated from the rest murfing into an entirely new specie. Making Devil's Hole the only place they exist in nature. The Devil's Hole pupfish is unique because it lives in pretty much the worst environment that you can think of to be a fish. The water is a constant 93 degrees Fahrenheit. Dissolved oxygen is at lethally low levels. Despite the difficult environment, many scientists believe Devil's Hole pupfish have been around for at least 10,000 years. In the mid to late 1960s, there was development here at Ash Meadows. And there was a local landowner that had land right against the 40 acres of Devils hole. So this landowner put a well right adjacent to the monument boundary. And when he turned on the well, the water level in Devils Hole Declined. With that, with this groundwater pumping, the population declining with the water level going down, the Devils Hole Pupfish was listed as an endangered species under the Endangered Species Preservation Act. That's way the National Park Service, along with the Fish and Wildlife Service and the Nevada Department of Wildlife are working together to monitor And try to save the doubles hole pup fish. A lot of their efforts rely heavily on technology. So it's managed by continuously monitoring the water levels so we have two transducers so a redundant system. We have it set to a telemetry system so we can actually type in and say what's the water level doing now? You also can see here we have this blue. Instrument hanging in the water, that's a water quality son, so it measures temperature, pH, oxygen, and connectivity at 15 minute intervals. Although Devil's Hole looks small from the surface, it's a massive underwater cave with unique conditions that make this project especially challenging. What's interesting about Devils Hole is it's such a large body of water, it's unknown depth, divers have been in 436 feet that it follows the lunar title cycle. So the water level goes up and down Twice in about a twenty-four hour time period. At one point, the Pufffish population at Devil's Hole dropped to just thirtyfive, which inspired the creation of a nearby lab where scientists and other staff are replicating the conditions at Devil's Hole for further study. We've created a 110,000 gallon habitat re-creation And it is largely computer driven and that is connected to a mechanical room filled with filtration, sterilisation, heating and thermal control systems to able to replicate a really challenging environment of devil's hole. There are currently about a hundred devil's hole pup fish living in the replica of site tank. The pup fish get in and out themselves. They're kinda cute. We like them. It was, we believe, a man-made problem that caused them to have trouble. We have a certain responsibility, we think, to be able to rectify that as much as we can. They're able to survive in environments that are lethal to most organisms. And a lot of the grand discoveries in science, biology especially, have occurred in extreme environments, and if we let them go extinct We'll never know. Why should we care? And I get that question a lot. So why should we invest the time and the money in conserving and preserving the species, and, I think, I have my NPS hat on now, I'm a scientist, I can put that on, I can put my society hat on And I think for me as a scientist, I still think we have a lot to learn from this ecosystem. And then putting on the society hat, well, that pumping that humans caused, that initial ground water pumping, that water level never came back up to its prepumping level. So we're having an influence. On the species, and if we hadn't, if it's a natural evolutionary pathway for the species, that's fine. Species do go extinct, and new species evolve, but since we've had a human impact on this ecosystem and the fish, I think As a society, we need to decide what is important. [MUSIC]