Lewis Center for Educational Research

Why is the Devils Hole Pupfish in danger of extinction?

"We really just don't know why," says Bob Williams, field supervisor of the U.S. Fish and Wildlife Office. Scientists still aren't sure why the Devils Hole Pupfish is on the brink of extinction. One thing they do all agree on is that water across the Mojave Desert is less abundant today than it was 11,000 years ago. Today's conditions are linked to a series of old or ancient (paleo-) tectonicand meteorological events...

Rising mountains to the west captured clouds, snow and glacial ice. The formation and subsequent drying of more than a half dozen valley-wide lakes due to the ever increasing effects of a growing "rain-shadow".	Pleistocene Lakes
Click on the top right image. A changing climate left only wisps of humidity above and cubic miles of a sand-filled, rock-lined basins holding prehistoric "fossil" water below,...resulting in the final desertification of water across the Pacific Southwest.	Mojave Desert Pupfish Species and their Habitat Locations

The below agencies oversee the management of the Devils Hole and its Pupfish.	The water that has remained is squeezed to the surface in precious few places across the arid land ecosystems of the Pacific Southwest. When and where water does come to the surface, creatures dependant on aquatic ecosystems have found refuge. One of these openings is called Devils Hole and one of these creatures is the Devils Hole Pupfish. To view the remaining "pupfish friendly" habitats locations across the Mojave Desert, click on to enlarge photo above. The entire exposed surface of the Devils Hole Pupfish's aquatic habitat consists of a space less than 60 feet long and 10 feet wide (18 x 3 meters). Inches below the surface, on a shallow rock platform, about the size of two pick-up beds, end to end, their continued existence is dependent upon the successful spawning of just one generation living only 6 to 12 months. The entire population may consist of as few as +/-38 adult individuals and an equal number of larval offspring (5/2006).

Where did the Devils Hole Pupfish come from? "When and how pupfish joined that community is something of a mystery, because there is no evidence that, since opening, Devils Hole has had a surface water connection to the perennial Ash Meadows springs." (A. C. Riggs and J. E. Deacon, 2002; page 33)

Some possible and often suggested hypotheses include:

• Swam an underground maze from one sunlit habitat to another (Not likely)
• Swam into the mouth of Devils Hole from outside eventually forming an isolated population (speculation only with little to no evidence to support either water flowing in or water flowing out; however, geologic evidence may have eroded away over the years.)
• Possible wind-aided dispersal of eggs or individuals (hypothetical mechanism)
• Eggs or individuals were or carried in by a non-human source (hypothetical mechanism)
• Eggs or individuals were carried in by a human source (hypothetical, improvable, but possible)

For more information concerning this question start reading on page 8 of the following report: "Connectivity in Desert Aquatic Ecosystems: The Devils Hole Story" (.pdf)

How do the Devils Hole Pupfish manage to survive?

For more information concerning this question start reading on page 16 of the following report: "Connectivity in Desert Aquatic Ecosystems: The Devils Hole Story" (.pdf)

How is the Devils Hole Pupfish doing?

For the latest information on Devils Hole pupfish recovery efforts and the status of the Devils Hole pupfish see the USFWS Devils Hole Recovery Actions webpage.

Want to visit Devils Hole?

For directions and maps to Devils Hole, click here.

What's New?

Catch up on the News from Devils Hole... Their numbers are up! The 2008 autumn count of the Devils Hole Pupfish has risen to 126, the first steady increase in more than a decade!