Las Vegas Sun

January 20, 2019

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The world and Devils Hole

Scientific name: Cyprinodon diabolis

Water temperature of Devils Hole, year-round: 92 to 93 degrees

Depth of Devils Hole: Unknown - at least 500 feet

Highest number counted: 553 in 1978

Average population through 1996: 324

Population count in November 2005: 84 (Does not count two dozen at Hoover Dam refugium.)

Pupfish life span: Eight months to a year

President Harry Truman called the pupfish: "A peculiar race of desert fish."

As go the Devils Hole pupfish, so goes the planet.

For scientists studying the endangered pupfish, its last stand has become a metaphor for other rare and threatened species.

The Devils Hole pupfish was one of the very first species classified by the federal government as endangered. If federal protection can't help the pupfish, could other endangered species be far behind?

"When you start to see species that have been around for thousands and thousands of years disappear, it serves as a forewarning that other species may be affected, and humans may ultimately be affected," said John Wullschleger, a National Park Service biologist stationed in Fort Collins, Colo.

"This species is a canary in a coal mine."

The aptly named fish - just an inch long - lives in a deep, vertical limestone cave in the Ash Meadows National Wildlife Refuge near Pahrump. Scientists and an assortment of federal, state and local officials are working to save the lowly pupfish as its population dwindles.

They have their work cut out. Only about 80 fish remain in Devils Hole.

The threatened extinction of the species is also a bellwether for the Endangered Species Preservation Act of 1966 and its follow-up in 1973, the landmark federal laws that mandated protections for "listed" species that are on the brink of extinction.

The listing ultimately led to a Supreme Court test in 1976, in which the country's highest court recognized the right of federal agencies to protect the cave's water supplies to support the pupfish, and by extension, water supplies needed for other endangered species.

Now, Wullschleger and his colleagues are in a race to find out what is killing the Devils Hole pupfish and reverse the slow die-off, a process that accelerated with the accidental killing of many of the fish in September 2004.

In that incident, scientific equipment stored at the mouth of the cave was washed into the water during a heavy summer flood. One-third to two-thirds of the remaining wild population of the species were killed.

Those guarding the pupfish - sometimes literally, since the cave is protected by razor wire to keep out unauthorized visitors - note that even before the 2004 incident, the population was declining.

What's worse for the species is that a population of them kept in an artificially maintained "refugium," essentially large aquariums, at Hoover Dam, also are declining. About two dozen fish remain there, down from about 100.

And neither the government officials nor the scientists know why.

Now the community of people working on the pupfish issues are stepping up the effort. The National Park Service, U.S. Fish and Wildlife Service and Nye County government will meet March 30 to discuss ways to save the fish. One step under consideration is creating new refuges and stocking them with fish taken from Devils Hole.

That's not an easy step to take, say those involved. Taking fish out of Devils Hole means an even smaller population in the native habitat. But the scientists say it may be the only way to safely find ways to boost the population.

"Some of the real tough decisions are in front of us," Bob Williams, state director of the U.S. Fish and Wildlife Service, said Thursday at a press conference outside the small, fenced area surrounding Devils Hole. "Those are critical questions that I feel uncomfortable making by myself."

Wullschleger said those involved in the effort don't have many options, and those that they do have, are dangerous.

"Everyone's doing the best we can with the knowledge we have right now, but we're in a really risky phase," he said. "The situation is critical. Every action we take right now is a high-risk action.

"We're keeping our fingers crossed."

The pupfish, which is closely related to several other species in the Southwest, is special also because it is unique to its location. Pupfish generally have provided clues to the development of the planet over the last several million years, said Jim Deacon, a UNLV professor emeritus in biology and natural resources.

"The Devils Hole pupfish has been an important part of the study of evolutionary biology," he said. "It has informed us a lot about the way, the pathways, that have been followed by early ancestors from millions of years ago."

The fish has ancestral relatives from the Middle East and Africa at a time when scientists believe North and South America were connected to the other continents.

Today, "some of their relatives occupy the Atlantic and Caribbean coastline from Virginia to Brazil," Deacon said.

Scientists suspect that the ancestors of the Devils Hole pupfish likely swam up the Rio Grande from home in northern Mexico, crossed over the Gila River in Arizona, made it into the Colorado River system and ultimately into the region around modern Las Vegas.

"The whole evolutionary-geological history through millions of years is pretty well outlined through the science that has been done," Deacon said. "The geology fits well with the biology to get from the Middle East to Ash Meadows.

"What we can't figure out is the geology to get into Devils Hole. We can figure out how they got halfway around the world, but we can't figure out how they jumped the last half-mile to Devils Hole."

The loss of those answers - and the ability to even ask the questions - would make us all poorer, Deacon said. Extinction because of the fish's interaction with humanity also would tell a tale of our ability to care for the planet.

"I believe my descendents deserve an opportunity to find answers to the questions of the Devils Hole pupfish, as they deserve to get answers to all the questions about all the species on Earth," he said.

"Our humanity is diminished when we abuse the world in a way that causes extinction that is human induced, a distinct from natural processes."

Wullschleger said extinction of the Devils Hole pupfish would erase a remarkable creature.

"The entire species is restricted to the smallest habitat of any known species on Earth," he said. "It's always been a mystery how the species got into the Devils Hole environment. There's no obvious connection to surface water.

"It's also a mystery because it occupies this relatively extreme environment and has done so for thousands and thousands of years. This small fish has managed to be a survivor."

Deacon takes a long view.

"To the extent that humans are the primary factor in making the pupfish or other species extinct, I consider it a failure of our stewardship responsibilities.

"A sustainable Earth sustains all species that live upon it. As we make it less sustainable by blinking out species so rapidly all over the world, we are making it a less desirable place to live on and making it less able to sustain our own species."