Local
Endangered Devils Hole pupfish rebound to 137 in fall count, nearly double spring total
The National Park Service counted 137 Devils Hole pupfish in October, up from 77 in spring and 69 last fall, offering a rare sign of recovery for one of the world's rarest fish. The species, which lives only in a single Death Valley cavern, remains vulnerable to earthquakes and habitat disruption.
The endangered Devils Hole pupfish, one of the rarest fish on Earth, saw its population nearly double since spring, with 137 fish counted during an Oct. 10 survey, the National Park Service announced. The count compares with 77 fish observed in the spring and 69 in fall 2025.
The fish live only in Devils Hole, a deep, water-filled limestone cavern in Death Valley National Park near Ash Meadows National Wildlife Refuge in Nye County. Scuba divers and surface counters from the Park Service and the U.S. Fish and Wildlife Service tallied the fish in the cavern's depths and along a shallow shelf where the pupfish feed and spawn. The two agencies have used those methods to monitor the population since 1972.
The population crashed to an all-time low of 35 fish in 2013 before rebounding to 191 in 2024, a 25-year high. The blue and yellow pupfish average less than an inch long and have no predators in Devils Hole, but they face scarce food and mostly stay within the top 80 feet of the cavern.
"It's exciting to see Devils Hole pupfish numbers increase so significantly over the past year," Death Valley National Park Superintendent Mike Reynolds said in a statement. "These results reflect the dedication of our scientists and conservation partners working to protect this extraordinary species. While challenges remain, we're encouraged by this progress and committed to its long-term survival."
The species remains vulnerable to earthquakes, which can send waves through Devils Hole and knock algae and other food off the limestone shelf. Two earthquakes in 2025 disrupted the habitat and contributed to population declines. After an Oct. 9 earthquake in Panama, nearly 3,000 miles away, biologists initially saw signs of stress in the fish but found them in healthier condition on a later visit, the agency said.
Scientists released 72 captive-raised pupfish into Devils Hole between March 2025 and February 2026. Because the species lives an average of 10 to 14 months, biologists believe most of the fish counted in October hatched and grew in Devils Hole, the Park Service said. Conservation teams also fed the fish while algae recovered, using data from the Fish and Wildlife Service's Ash Meadows Fish Conservation Facility and the Park Service's monitoring program.
The Fish and Wildlife Service maintains a backup population at a facility about a mile from Devils Hole. Its 100,000-gallon tank closely mimics the hot, low-oxygen water of the cavern so fish can be returned to Devils Hole if something happens to the wild population.
The Park Service said pupfish populations naturally fluctuate and that continued monitoring, research and habitat management remain essential to the species' survival.