Biologists are trying to stabilize the number of Devils Hole pupfish in Nevada. There are just 75 of the fish left in the world.
The Devils Hole Pupfish is blue. It's just an inch long and has about a year-long lifespan. And it lives in one isolated spot -- a cave-like pool on the edge of Death Valley National Park.
Biologists who make at least two counts a year -- one in the spring, one in the fall -- don’t know the exact reason that numbers are down a third from last year. They say an uptick in global earthquakes or a warmer climate could be part of the problem.
Efforts to save this endangered fish have cost millions of dollars. And Ted Koch of the Nevada Fish and Wildlife Office says the agency is trying to get the numbers back up.
"We could choose to take some individuals from the hole and try to propagate them in captivity. It’s been tried before with varying levels of success," Koch said.
But so far, biologists haven't succeeded in creating a reliable man-made environment to breed more pupfish.
They have protected Devils Hole itself from potential acts of vandalism by having a fence around it and they've fed pupfish on and off over the years to ensure they have adequate nutrition.
The fish went on the list of endangered species in 1967.
"One of the primary purposes of the Endangered Species Act is to conserve ecosystems upon which species depend," Koch said. "This ecosystem is one small hole in the Mojave Desert. So it doesn’t have far-reaching effects necessarily. But obviously we do care about all living things. This is a species that was naturally rare when Europeans arrived and we’re doing all we can to make sure it has every opportunity to survive as long as possible."