"Desert pupfish in hot water"

Only 42 left: Creature whose plight led to the Endangered Species Act is on the brink -- researchers don't know why...

Death Valley National Park -- The last place anyone would expect to find fish is Devil's Hole, a chasm in the middle of the Mojave Desert where a 100-degree day is mild and the only thing bigger than the rocky expanse of desert is the sky above it.

But nature is nothing if not amazing -- as good an explanation as any of how the Devil's Hole pupfish has survived in the bottomless geothermal pool that gave the fish its name. It is tiny, just an inch long, yet few species loom so large in the history of American environmentalism.

The Devil's Hole pupfish is one of the rarest animals in the world. The seemingly endless effort to save it laid the foundation for the Endangered Species Act and shaped Western water policy a generation ago with a landmark Supreme Court ruling.
But after 20,000 years in the desert, the fish teeters on the edge of extinction. No more than 42 remain in Devil's Hole.

The Devil's Hole pupfish has been the beneficiary of one of the most aggressive campaigns ever to preserve a species, an effort every bit as intense as those to save the bald eagle and California condor. The Endangered Species Act requires nothing less. But saving the pupfish is more than a legal obligation for the biologists and bureaucrats involved.
It's a moral one.

"This fish is the species that made us take note of our need for conservation," said Mike Bower, a National Park Service fish biologist. "It made us realize that our actions have an impact beyond us. We have a responsibility to look after this fish."
No one knows why they are vanishing. No one knows what it might say about the health of the desert. And no one knows whether they can be saved.

More than the loss of a species is at stake at Devil's Hole. A deeper question has been posed in the desert outside Las Vegas, where scientists have spent the better part of 60 years trying to keep the pupfish alive: Should we even bother? Or are we only delaying the inevitable?

evil's Hole is just that -- a hole on the side of a hill overlooking an oasis called Ash Meadows. It's about the size of a mineshaft and looks about as interesting.

But beneath the surface lies a limestone labyrinth filled with crystal-clear water that fell as rain eons ago. A diver once descended to 450 feet, and researchers once sent a camera 100 feet beyond that. It keeps going from there. How far is anyone's guess.

Yet the pupfish spend most of their time foraging and spawning on a rock shelf just below the surface of the water. They live in almost complete isolation in alkaline, 93-degree water that contains very little oxygen. They feed on algae, snails and other tiny invertebrates in what is one of the world's smallest ecosystems...