LAS VEGAS (AP) — A 65-year effort to save an isolated fish in a unique desert ecosystem near Death Valley might be coming to a sad end, federal officials said.

Only 35 Devil's Hole pupfish were found in the latest U.S. Fish and Wildlife Service survey, the Las Vegas Review-Journal reported (

That's the lowest tally ever for the tiny endangered fish found only in one water-filled cavern in Nye County, about 90 miles west of Las Vegas.

Ted Koch, state supervisor of the Fish and Wildlife Service, said officials are very concerned but aren't giving up efforts to save the species.

"When you get this low, anything can happen and you're in a grim situation," he said.

But he noted the previous lowest totals on record were 38 in the spring of 2006 and 2007.

"So we've been here once before and bounced back," Koch said.

This time, the bleak spring tally comes on the heels of the lowest fall count ever — just 75 adult fish.

The neon blue pupfish and its habitat have been under federal protection since 1967, and are counted twice a year. The population peaked at 544 in the fall of 1990, but began to decline in 1996 for reasons researchers still can't explain.

The low numbers in 2006 and 2007 came after scientists mistakenly left a container of fish traps next to Devil's Hole in 2004. A flash flood dumped the traps into the pool, catching and killing about a quarter of the fish population.

Experts can't explain what is happening to the pupfish now.

Jim Deacon, a biologist and founder of the environmental studies program at the University of Nevada, Las Vegas, made his first visit to Devil's Hole in 1961. He used to scuba dive regularly in the cavern's thermally heated water to count the tiny fish.

In the 1970s, he testified in defense of the species during a legal fight over groundwater pumping that threatened to empty Devil's Hole. The case ended in a landmark U.S. Supreme Court decision in favor of the fish.

Today, Deacon and others worry that the population may have shrunk so low that the species is no longer genetically viable.

"I don't know what the minimum number is likely to be," Deacon said. "It's possible that we're seeing genetic meltdown."

Another theory is that food and spawning beds were disturbed by flood debris in August and by several strong but distant earthquakes last year that sent water sloshing in the pool.

Koch said Fish and Wildlife Service research partners plan to keep providing supplemental food to the fish. They also may try to add more organic material to the pool to replace what was washed away by the earthquakes.

Meanwhile, efforts to raise Devil's Hole pupfish in captivity have failed.

If the Devil's Hole pupfish cannot be saved, it will join Florida's Dusky seaside sparrow on the list of endangered species that have died out while under federal protection.

But Deacon said that within the uncertainty lies hope: Perhaps the pupfish will stage a comeback after all — and for reasons that researchers don't entirely understand.

"There's hope that they will be able to recover from this point," he said.


Information from: Las Vegas Review-Journal,