Without the 7-foot-tall chain link fence, barbed wire and security cameras, Devils Hole would likely go unnoticed – blending into the vast desert in Death Valley National Park.
Surrounded by rocky terrain and scattered brush, the road – little more than a trail at some points – winds its way up the valley side to a high, brown ridge. Not much indicates the area’s ecological diversity. But soon the fence comes into view. Inside is a limestone cavern holding a living treasure, the rare and endangered Devils Hole pupfish.
Access to the site is extremely limited even among experts in the field, said Craig Stockwell, professor of biological sciences at NDSU. But due to his expertise on two scientific panels concerning the pupfish, he was able to take 10 students in his Advanced Conservation Biology course there for a rare learning experience last fall.
“I told the students this was my second time at the site in 20 years,” Stockwell said. “You are very unlikely to find many people who have been there more in a career. It has iconic status for people who study conservation of aquatic species.”
A classroom like no other
A uniformed National Park Service officer welcomed the students and unlocked the gate. Students climbed down a steep decline covered with bits of rock. Be careful not to kick any of it into the hole, they’re told. That would disturb the habitat.
A giant boulder provided a prime viewing spot of Devils Hole’s water-filled cavern, which is accessible because a portion of its roof collapsed. The opening provides a window to the pupfish’s only natural habitat, a small shelf covered by rubble and three feet of water, which stays a consistent 93 degrees Fahrenheit. The edge of the shelf drops into an abyss whose bottom has yet to be found.
The pupfish, which are iridescent blue and the size of a thumb at their largest, get their name for resembling puppies at play. The fish and their home offered an immersive learning environment for Samantha Skinner, a senior majoring in zoology from Hazen, N.D. “It was touching ground that people don’t get to walk on.”
Skinner, under the guidance of doctoral student Shawn Goodchild, conducts research on pupfish in Stockwell’s NDSU lab. She used the trip to trap, study and release samples of the Amargosa pupfish at a pool near Devils Hole. This species, which also is highly endangered, occurs only in a few habitats. Her work helped determine the impact of non-native and invasive mosquitofish on the pupfish.
“I had been doing work on these sites, but hadn’t actually seen it,” Skinner said. “I got to actually see what I had been working on – a true hands-on experience.”
Conservation biologists have been working to save the pupfish and its relatives scattered throughout isolated sites in the valley. Some fish have found new homes at the Ash Meadows Fish Conservation Facility, a refuge site created after ranching activities threatened the fish’s future. Students toured the facility before attending a special symposium at the Desert Fishes Council Meeting, which Stockwell co-organized.
They later visited Rancho Santa Ana Botanic Garden, the San Diego Zoo and the zoo’s Institute for Conservation Research during the nine-day trip.
How did the fish get there? The pupfish’s habitat once was covered with water – a remnant of a Pleistocene lake. Most are believed to have been isolated thousands of years ago as the water receded. “As lake levels dropped, the Devils Hole pupfish was isolated at a higher elevation,” Stockwell said. “The last two species in the bottom of the valley were isolated 2,000 years ago. It’s an example of rapid diversification.”
While their numbers fluctuate, only about 100 pupfish remain in Devils Hole. In the 1960s, irrigation and urban development tapped into groundwater in the area, lowering the aquifer level and threatening to expose the cavern’s shelf, which is the fish’s only natural breeding habitat. A legal battle wound its way to the Supreme Court and biologists have since erected the fence to prevent intruders from intentionally harming the fish.
Now protected by the National Park Service, access is limited to a lucky few. For the NDSU students who visited the area, it was a chance to experience the ultimate irony – driving into the middle of a desert to study a fish.