Pupfish Population Increasing

Photo by Stephen Osmon, Los Angeles Times


We wrote about the incredibly rare Death Valley pupfish last year, after we saw them in their tiny Devils Hole habitat in Nevada. Now the New York Times and the Los Angeles Times report that the fall count of the pupfish shows an increase in population. The pupfish, an isolated species whose numbers were down as low as 38 in 2006, now number 126. They numbered close to 500 as recently as the mid-1990s.

The counts are done in spring and fall; spring counts are typically much smaller than fall because the pupfish have a greater die off in the winter months. They are counted in the shallow rock shelf where the majority of them feed and spawn, and by divers who reach the 100 foot depths where others may swim. They are counted twice a day, and the numbers averaged for a total population figure

Biologists are not sure why the species has dwindled so precipitously since then, but suspect that a lack of nutrients is to blame. To remedy the situation, they took the highly unusual step of developing a specialized, high-nutrient fish food similar to food used to feed minnow at a New Mexico hatchery.

"It was not done lightly," Bob Williams, Nevada field supervisor for the U.S. Fish and Wildlife Service, told the L.A. Times. "When you start to artificially augment a wild population, it is a sign the species is really in trouble."

Click here for more information on the Amargosa Valley pupfish station or the pupfish home page at http://www.fws.gov/Nevada/protected_species/fish/species/dhp/dhp.html.

Death Valley Wildlife

Although arid and unforgivingly harsh, Death Valley is home to an impressive number of mammals, reptiles and birds. The elevation ranges from below sea level (at Badwater) to sub-alpine conditions at Telescope Peak (11,000 ft.). The resulting habitat variations support 51 species of mammals (including mountain lions, mule deer and desert bighorn), three species of amphibians, and more than 300 species of birds. The bird species and their populations increase and decrease with the seasons, with some species making uncommon or “casual” visits from one year to the next.


But the record rainfall and the overabundant wildflowers that spring lured even hummingbirds to Death Valley, a bird we didn’t expect to find in the extreme desert. They were plentiful enough in the blooming vegetation around Scotty’s Castle, and were a pleasure to see.


Another surprising species in Death Valley is fish. At the end of the last ice age, when Lake Manly dried up and left the Valley barren, pockets of water were left behind. The pupfish adapted to the concentrated salinity and survived in a shallow part of Salt Creek that flows above ground. Because of the confined area of their evolution, Salt Creek pupfish exist nowhere else in the world. Similarly, there are Saratoga Springs pupfish found only in the Saratoga Springs at the south end of the Valley; the Amargosa pupfish, found in the nearby Amargosa River; and the Devil’s Hole pupfish, located just over the state border in Nevada. A subspecies of pupfish lives in the Valley’s Cottonball Marsh. There are small bridges where you can walk alongside Salt Creek and view the pupfish. Sadly, the Devil’s Hole pupfish are so rare that you can only see them through a fenced off little area of what looks like, yes, a hole just big enough for the Devil to emerge from hell.