Have you ever felt stuck in a bad situation that you couldn’t get out of, through no fault of your own, and all you could do is just make the best of it?
Such is the life of the Devils Hole pupfish.
This small, iridescent blue-or-green fish swims in the hot waters of an inhospitable fishbowl made of rock in a Nevada section of Death Valley National Park, where it somehow got trapped thousands of years ago.
The deep cavern that is this fish’s only home is surrounded by a chain-link fence, razor wire, and other security measures designed to protect this incredibly rare endangered species.
In 2013, its population hit a low of only 35 fish. But over the last couple of years, the Devils Hole pupfish has bounced back, thrilling and somewhat baffling wildlife managers who still are trying to figure out how this tough little fish manages to make a go of it.
Last year, in the spring, they counted 175 observable fish. This spring, the count was the same, which means that the population has been holding steady.
A wild population of just 175 fish doesn’t sound like a lot. But this is the best the Devils Hole pupfish has been doing in about two decades.
“Times are good now with Devils Hole pupfish, compared to how they’ve been in the past,” says Jenny Gumm, a fish biologist with the U. S. Fish and Wildlife Service.
Exactly how the pupfish have recovered to this point is a bit of a mystery.
“The question that I receive and my colleagues receive is, ‘Why?’ And you know, we’re trying to answer that,” says Kevin Wilson, an aquatic ecologist at the National Park Service.
A fish that’s able to cope
Wilson first learned of this iconic fish as a kid back in the 1970s, when he tagged along with his geologist mom on a field trip that stopped by Devils Hole.
“I just remember as a young lad just laying down on this wooden observation deck, looking down into this immense hole in the ground and was fascinated,” says Wilson.
At the bottom of the hole is the pool where the fish swim. No one knows how deep it is — scuba divers have explored to a depth of over 400 feet.
The pupfish, which are only about an inch long, have no natural predators. Without fear, they’ll curiously swim up to inspect divers or anything else that enters their isolated world.
The fish tend to hang out near the top of the pool, swimming around in the shallow water that covers a rocky ledge. There, they feed on algae and spawn.
The water isn’t exactly cozy. “It’s 93 degrees fahrenheit all the time,” says Wilson, and its oxygen levels are low.
Plus, for about four months in winter, the pool remains entirely in shadow, which is not good for the tiny plants that the fish eat.
“It’s not a great place to live if you’re a fish, that’s for sure,” says Gumm.
The reduced amount of food in winter is thought to be why spring counts of this fish have historically been lower than counts done in the fall. Last fall, researchers observed 263 fish. The next count will come in September.
“I’m hoping that we cross the threshold of 300,” says Wilson.
Earthquakes and flash floods
Part of this fish’s recent revival may be due to some dramatic events that have shaken up life in Devils Hole.
In July of 2021, a rare flash flood poured in an enormous amount of muddy water.
“The volume of water that went into the habitat was just so much,” says Gumm, who worried the fish would die from a change in water chemistry — or even just the sheer violence of the flood and its churning debris.
It was the first time Gumm felt like these fish really might go extinct on her watch. She recalls going to the hole just after the flood.
