America’s rarest fish makes stunning comeback in Southern Nevada
The Southern Nevada fish thought to be the world’s most endangered has made a stunning rebound.
During a fall count in Death Valley National Park’s Devils Hole, next to the Ash Meadows National Wildlife Refuge, biologists counted 137 Devils Hole pupfish, up from 77 last spring and 69 last fall.
“These results reflect the dedication of our scientists and conservation partners working to protect this extraordinary species,” Death Valley National Park Superintendent Mike Reynolds said in a statement. “While challenges remain, we’re encouraged by this progress and committed to its long-term survival.”
The Devils Hole pupfish earned its endangered listing under the federal Endangered Species Act in 1967 in response to the major threat of groundwater drawdown from ranching and agriculture.
The U.S. Supreme Court intervened, too. In its decision on 1976 Cappaert v. United States, the court upheld the ruling that ranchers could not pump groundwater in a way that would affect levels at Devils Hole and undermine the federal government’s mission of conservation at what was then a national monument.
Count shows progress, officials say
The National Park Service and U.S. Fish and Wildlife Service have been counting the pupfish since 1972.
Twice a year, biologists dive into Devils Hole to conduct the pupfish count while others count those that swim around on the surface. The true depth of Devils Hole is still a mystery to scientists.
Devils Hole is particularly vulnerable to earthquakes. According to the park service, two of them in 2025 contributed to species decline because the movement disrupted algae and other food sources.
When an earthquake in Panama shook Devils Hole in early October, however, the park service said scientists observed that populations remained stable.
In addition to scientists helping recover algae as a food source, the release of captive-bred fish is making a difference.
A few miles away from Devils Hole, a full 3D recreation of the habitat exists indoors within a 100,000-gallon tank.
To promote recovery, scientists released 72 captive-bred pupfish into Devils Hole between March 2025 and February 2026. And because the fish only live between 10 to 14 months, biologists say most of the 137 fish observed during the fall survey hatched and grew in Devils Hole.
“Although Devils Hole pupfish populations naturally fluctuate, the latest count represents encouraging progress in efforts to protect one of the world’s rarest fish,” a news release said. “Continued monitoring, research and habitat management remain essential to the species’ long-term survival.”
Contact Alan Halaly at ahalaly@reviewjournal.com. Follow @AlanHalaly on X.
