One night late last month, three drunken idiots thought it would be a great idea to go off-roading in one of the world's most carefully protected conservation sites. They brought a shotgun, which one of them used to obliterate the locks securing two gates and the motion sensors that otherwise would have kept them well away from Devils Hole, a deep, warm pool that is home to a critically endangered fish.

The phrase *critically endangered *can seem abstract, but in this case, it's easy to wrap your brain around. These tiny blue-silver Devils Hole pupfish, less than an inch long, live nowhere else but here, in this one spot in Death Valley National Park. At last count, in April, just 115 remained, in a long, narrow pool about the length of a shipping container. Although that pool is more than 500 feet deep, the fish spend their lives foraging on a rock ledge just below the surface.

Over the past 50 years or so, the Devils Hole pupfish has become a conservation icon, forcing ecologists to experiment with new methods to try to save them—and inciting debate over whether some of them go just a bit too far. “There’s been really heroic efforts to save this species,” says Craig Stockwell, a conservation biologist at North Dakota State University.

Which makes it all the more infuriating that three morons broke in, killing at least one pupfish, stomping on the ledge that protects their eggs, vomiting, and—in a truly classy touch—leaving a pair of dirty boxers floating on the water's surface.

This is not the first time humans have mucked with the pupfish. In the 1960s, groundwater tapping threatened to drain Devils Hole and expose the ledge, prompting the Supreme Court to step in and protect the species. In the early 2000s, a flash flood sent some researchers' fish traps into the aquifer, killing a third of the population. "It was pupfish 9/11," says Christopher Martin, a biologist at the University of North Carolina Chapel Hill.

The poor pupfish has it bad enough without all those shenanigans. Given its tiny population, scientists suspect the fish is now severely inbred, bogged down by harmful mutations that hinder reproduction and survival. Beginning in the 1970s, researchers explored ways to revitalize the population, mostly by breeding the fish in captivity. Historically, those efforts had little success. "Due to high genetic load, the fish are kind of on the edge," says Stockwell. "Any change in their environment changes their reproductive capacity."

More recently, biologist Andy Martin has embraced a more controversial strategy—crossbreeding the Devils Hole pupfish with a neighboring species, the Ash Meadows Amargosa pupfish, in a kind of genetic rescue. The same technique helped revitalize an inbred population of Florida panthers. But it's hardly kosher by most conservationists' standards.

Purists argue that crossing a Devils Hole pupfish with another species means it's not a Devils Hole pupfish anymore. "The big thing to keep in mind here is, why are you even trying to keep the species around?" says Martin. In some cases, like the Florida panther, you must maintain a population to keep the surrounding ecosystem healthy—ecosystem services, as he puts it. That's not as important when you're dealing with one isolated hole in the Nevada desert, where the water is 92 degrees, alkaline, and low in oxygen.

No, this pupfish's value lies in its very instability. "The reason we find it so fascinating, I think, is that it's stuck in this tiny hole," says Martin. "Hybridizing to me has missed the point of conserving this species," which is to study an animal that has learned to survive in such an inhospitable environment (and in the face of astounding stupidity on its human neighbors' parts).

In recent years, it seems, captive breeding programs for the Devils Hole pupfish have done fairly well. The pupfish lay eggs on a carpet draped across the spawning ledge, then researchers take the eggs to the lab and hatch them in an aquarium that mimics their natural habitat. No one plans on throwing Ash Meadows Amargosa pupfish into Devils Hole anytime soon, so the species' genetic legacy remains intact for now. But the debate over the best way of caring for this extraordinary species is far from over.

Martin thinks the solution lies somewhere in between: He wants to study the Devils Hole pupfish genome and identify exactly what mutations are causing trouble. Then he wants to fix them, one by one, using the gene-editing technique Crispr—not by doing a full-on cross with another species. "That, to me, is real genetic restoration," he says.

Those questions won't have good answers for a while yet. In the meantime, conservationists will wait to see just how much of an effect this most recent assault has had on the pupfish population. "Three inebriated grown men could have a pretty profound effect on the habitat," says Stockwell, "depending on how many eggs were there."

One thing is for certain, at least: DNA collected at Devils Hole has identified the three vandals. They'll face a number of charges, including killing an endangered species—a felony.