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June 10, 2005
Devil's Hole a real hell for imperiled prehistoric pupfish
By PHILLIP GOMEZ
• The 93-degree constant water temperature in which it lives within the barren cavern in the Amargosa Valley has been steadily declining in depth. • The water's diminishing depth means a loss of oxygen, as necessary to life for the fish as it is for humans; and a lowered water level raises its temperature, contributing to algae blooms that crowd out the fish. • The pupfish's algae food source is limited and easily imbalanced by available sunlight. Owl droppings contribute the most nutrients. • In its lifespan, a mere 10 to 12 months, a female fish typically produces 10 or fewer eggs, of which only two or three larvae hatch to begin again the reproductive lifecycle. Isolated for 10,000 to 20,000 years in the cavern, the Devil's Hole pupfish as a species is headed for extinction. The cause may be the encroachment of civilization and its increasing draw on the desert aquifer that is life support to the fish. No one knows for certain, but the suspicion is that development in the Pahrump Valley adversely affects the aquifer downgradient in the Amargosa Desert, lowering the water table in Devil's Hole. Even more deeply mysterious, scientists simply don't know what the ultimate repercussions for humans will be with the disappearance of the tiny pupfish from the face of the earth. Just from a moral standpoint, how would you feel if, in the grand cosmic scheme of things, you were born a pupfish? From a biblical perspective, humans have a stewardship responsibility for the fish. Recognizing this, the United States Supreme Court in 1976 decided to limit groundwater pumping in order to guarantee the fish would have enough water to cover the rock shelf on which they feed and eek out a life. Earlier this week, the newspaper met with National Park Service staffers from Death Valley National Park who monitor the pupfish's well being. Ranger-interpreter Nancy Hadlock, wildlife technician Linda Manning, fisheries biologist John Wullschleger, and resource technician Eileen Wong rendezvoused at Devil's Hole in the dark of night. Hadlock started working for the Park Service in April, stationed out of the Ash Meadows Wildlife Refuge headquarters. The Park Service pupfish squad, as they might be called, was at Devil's Hole to do its monthly count of the pupfish larvae, a rite enacted since 1972 when a three-year drop in the water-level, due to nearby agricultural pumping, reached its nadir. The carbonate rock outcrop marking the site on the refuge loomed darkly against the night sky. "It's not everyday that you get to look at the underground aquifer," says Manning as we walked toward the cavernous entrance to Devil's Hole. The pupfish squad had to wait until two hours past "civil twilight" before it began its work. In Pahrump, civil twilight during the second week of June occurred at 8:30 p.m. It's the time when descending darkness limits your ability to see, but you can still see well enough to move about. The reason for this precaution is that to count larvae pupfish, which are so tiny they can barely be seen, you have to wait until they come out of the rock substrate in which they live. More than the stars, they don't come out until well after dark because that's when the adult pupfish, out preying for food during the day, retire. To add to the pupfish's already harsh struggle for existence, young pupfish have to watch out that they don't become food for the adults, limited as they are to scarce sources. That's why the puppy pupfish, like war-torn refugees in bombed out city rubble, don't expose themselves until after dark, which is why we had to wait until exactly 10:30 p.m. before the squad could begin its carefully coordinated, scientifically conducted census. The Park Service wants to get an accurate count each month to detect population growth or decline; so all things must be equal each time a count is conducted. "In a year, it'll be the offspring of the fish that are here tonight that we'll be counting, because the population has turned over," says Wullschleger. The Park Service, founded on the idea of protecting wildlife and scenery - but also mandated in its organic act to provide park visitors with "the enjoyment of the same in such manner and by such means as will leave them unimpaired for future generations" - may have met its ultimate challenge in reconciling the two - squaring the circle with the pupfish and the public. Minimal interpretation currently is provided the visiting public regarding Devil's Hole. The area remains fenced off from the public, as it has since 1952 when the area became part of Death Valley National Monument. For now, the Park Service is focusing on protecting its charge. No one seems to know where the name "Devil's Hole" originated. Historically, the area was a no-man's land to the Southern Paiute, then living in the Pahrump Valley, and the Timbisha Shoshone who resided in Death Valley. The moniker may have been bestowed when the Park Service was given responsibility for protecting Cyprinodon diabolis, the devilfish. With the Park Service's chain-link gate unlocked, the group ducked under and descended down the 18-foot aluminum ladder into the depths of Devil's Hole. In 1965, three high school students tried to go scuba diving in the hole, but were warned away by park rangers. They snuck back at night and went anyway. Tragedy would claim the day. No one knows the depth of the hole, but its twisted narrow channel emerges 60 meters down into a cavernous room. Park Service divers have measured its depths to 436 feet and were able to see another 500 feet with no end in sight. The bottom has never been mapped. One of the youths didn't surface, and the other two went back down for him. Only one returned. Rescue divers searching for three days in the labyrinthine dark passages could not find them. They concluded that the youngsters probably had become disoriented and drifted deeper into the cavern, hopelessly unable to find their way out. "They may have gone down in that darkness thinking they were going up," said Manning. The overall sense in the cave, where the squad went dutifully about its work, was one of peacefulness. If you didn't know its biology and history, you would never sense the violence and death associated with Devil's Hole. Crickets loudly chirped, their sounds echoing inside the cavern; a pair of barn owls screeched; moths and other flying insects flitted about in our lamplight. A large chuckwalla is supposed to guard the entrance, but I didn't see him. On the rock shelf where the pupfish thrive, it's only a shallow four to 24 inches deep, but at the far end the hole deepens to about 25 feet and goes to further depths from there. In the early 1960s the Park Service began monitoring water levels inside the cavern. The area around Ash Meadows was being intensively farmed and irrigated. By 1967 the decreasing water levels had so alarmed biologists that the species was listed in the Endangered Species Act. In the early 1980s the U.S. Fish and Wildlife Service designated 21,000 acres around Devil's Hole as essential habitat, a protective measure to safeguard the groundwater in which the fish survive. In 1984 the Wildlife Service purchased the land and designated it a refuge. Other endangered and threatened species are protected as well. Water monitoring hydrographic equipment in the hole tracks the daily and annual levels to which the water rises or falls. In any 24-hour period the water level will naturally vary three or four inches, Wullschleger explained. Devil's Hole is one of 30 seeps or springs at Ash Meadows, "fossil water," thousands of years old flowing under the surface from 100 miles away to the northeast, until finally escaping through a geologic fault, making wetlands in the middle of the Mojave Desert. What makes Devil's Hole unique and darkly mysterious is the animal that survives along with the water. The Ramsar Convention, an international treaty of 136 countries, has listed Ash Meadows as a "wetland of international importance." Devil's Hole - the tiniest of federally protected natural areas - ironically is part of the nation's largest national park, Death Valley. Now, as an indication of how critically important the Park Service views the pupfish and its survival, the agency has assigned a new ranger-interpreter stationed on-site at Ash Meadows National Wildlife Refuge to provide the visiting public with information about the pupfish and its imperiled state at Devil's Hole. Hadlock wants to outreach to teachers and school kids to present off-site school programs for curriculum enlargement, as well as for interpretive programs for adults regarding Devil's Hole. "No group is too small," Hadlock said. She can be reached at the wildlife refuge contact station: (775) 372-5435. |
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