The Man Who Saved the Owens Pupfish

51 years ago today a man named Edwin Philip Pister rescued an entire species from extinction.

This is a happy story, but first we need to get through the downer stuff:

The news is full of extinction stories. A species that once thrived runs headlong into the modern world and vanishes. Habitat disappears, invasive species arrive, ecosystems unravel, and before long another name is added to the list of things that used to exist.

The numbers are grim. The International Union for Conservation of Nature (IUCN) Red List reports that about 900 species have gone extinct since the year 1500, the baseline used for “modern extinctions.” Further, more than 48,600 species are threatened with extinction; that’s about 28% of all assessed species. Many believe we are living through the Anthropocene, a period in which human activity has become the dominant force shaping the planet. For many plants and animals, it is an era they simply cannot survive.

Elizabeth Kolbert captured the scale of the problem in her book The Sixth Extinction. I’ve read it. It’s great, if depressing.

But every so often, there are stories that tick in the other direction. Small victories. Species that somehow slip through the cracks and hang on.

Amanda Royal over at Earth Hope does a wonderful job documenting some of those rare moments of recovery. And there are more of them than you might think if you look closely.

One of them begins in the high desert of California’s Eastern Sierra, with a fish no longer than your finger.

The Owens pupfish.

Its story is not a sweeping comeback. The species is still endangered and survives only in a few carefully protected places. But its survival came down to the actions of a handful of people and, in one crucial moment, the determination of a single biologist who refused to let an entire lineage disappear.

Sometimes that is all it takes to change the ending.

Less than 2.5 inches in length, the Owens pupfish is a silvery-blue fish in the family Cyprinodontidae, part of a group of small egg-laying fishes that includes killifish and topminnows. Endemic to California’s Owens Valley, 200 miles north of Los Angeles, the fish has lived on the planet since the Pleistocene, becoming a new species when its habitat was divided by changing climatic conditions, 60,000 years ago. The fish is a survivor. But of course, as is too often the case, when man comes along, even the most hardened creatures face peril.

For thousands of years, the Owens Valley was largely filled with water, crystal-clear snowmelt that still streams off the jagged, precipitous slab faces of the Sierra Nevada mountains. Pupfish were common, with nine species populating various lakes and streams from Death Valley to an area just south of Mammoth Lakes. The Paiute people scooped them out of the water and dried them for the winter.

In the late 19th century, Los Angeles was a rapidly growing young metropolis, still in throes of growing pains that would last decades. While considered an ugly younger sibling to the city of San Francisco, Los Angeles had the appeal of near year-round sunshine and sandy beaches whose beauty that rivaled those of the French Riviera. And still do.

But by the late 1900s, the city began outgrowing its water supply. Fred Eaton, mayor of Los Angeles, and his water czar, William Mulholland, hatched a plan to build an aqueduct from Owens Valley to Los Angeles. Most Californians know the story. Through a series of shady deals, Mulholland and Eaton managed to get control of the water in the Owens Valley and, in 1913, the aqueduct was finished. It was great news for the new city, but terrible news for many of the creatures (not to mention the farmers) who depended on the water flowing into and from the Owens Lake to survive.

So named because they exhibit playful, puppy-like behavior, the Owens pupfish rapidly began to disappear. Pupfish are well-known among scientists for being able to live in extreme and isolated situations. They can tolerate high levels of salinity. Some live in water that exceeds 100° Fahrenheit, and they can even tolerate up to 113° degrees for short periods. They are also known to survive in near-freezing temperatures common in the lower desert.

But hot or cold are one thing. The disappearance of water altogether is another.

As California has developed, and as climate change has caused temperatures to rise, thus increasing evaporation, all of California’s pupfish populations have come under stress. Add to these conditions, the early 20th-century introduction by the California Department of Fish and Wildlife of exotic species like largemouth bass and rainbow trout to lakes and streams in the eastern Sierras (bass and trout readily prey on small fish), and you get a recipe for disaster. And disaster is exactly what happened.

Several species of pupfish in the state have been put on the endangered species list. Several species, including the Owens pupfish, the Death Valley Pupfish and the Devils Hole pupfish are some of the rarest species of fish on the planet. The Devils Hole pupfish recently played the lead role in a recent (and excellent) story about a man who accidentally killed one of the fish during a drunken spree. According to news stories, he stomped on the fish when he tried to swim in a fenced-off pool in Death Valley National Park. He went to jail.

The impact on the Owens pupfish habitat was so severe that in 1948, just after it was scientifically described, it was declared extinct.

That is, until one day in 1964, when researchers discovered a remnant population of Owens pupfish in a desert marshland called Fish Slough, a few miles from Bishop, California. Wildlife officials immediately began a rescue mission to save the fish and reintroduce them into what were considered suitable habitats. Many were not saved, and by the late 1960s, the only remaining population of Owens pupfish, about 800 individuals, barely hung on in a “room-sized” pond near Bishop.

On August 18, 1969, a series of heavy rains caused foliage to grow and clog the inflow of water into the small pool. It happened so quickly, that when scientists learned of the problem, they realized they had just hours to save the fish from extinction.

Among the scientists who came to the rescue that day was a stocky, irascible 40-year-old fish biologist named Phil Pister. Pister had worked for the California Department of Fish and Game (now the California Department of Fish and Wildlife) most of his career. An ardent acolyte of Aldo Leopold, regarded as one of the fathers of American conservation, Pister valued nature on par, or even above, human needs. As the Los Angeles Times put it in a 1990 profile, “The prospect of Pister off the leash was fearsome.”

“I was born on January 15, 1929, the same day as Martin Luther King—perhaps this was a good day for rebels,” he once said.

Because of his temperament, Pister had few friends among his fellow scientists. He was argumentative, disagreeable, and wildly passionate about the protection of California’s abundant, but diminishing, natural resources.

Pister realized that immediate action was required to prevent the permanent loss of the Owens pupfish. He rallied several of his underlings and rushed to the disappearing pool with buckets, nets, and aerators.

Within a few hours, the small team was able to capture the entire remaining population of Owens pupfish in two buckets, transporting them to a nearby wetland. However, as Pister himself recalls in an article for Natural History Magazine:

“In our haste to rescue the fish, we had unwisely placed the cages in eddies away from the influence of the main current. Reduced water velocity and accompanying low dissolved oxygen were rapidly taking their toll.”

AAs noted earlier, pupfish are amazingly tolerant of extreme conditions, but like many species, they can also be fragile, and within a short amount of time, many of the pupfish Pister had rescued were dying, floating belly up in the cages. Pister realized immediate action was required, lest the species disappear from the planet forever. Working alone, he managed to net the remaining live fish into the buckets and then carefully carried them by foot across an expanse of marsh. “I realized that I literally held within my hands the existence of an entire vertebrate species,” he wrote. “I remember mumbling something like: “Please don’t let me stumble. If I drop these buckets we won’t have another chance!”

Pister managed to get the fish into cool, moving water where they could breathe and move about. He says about half the the population survived, but that was enough.

Pister died in 2023 near Bishop, and today, the Owens pupfish remains in serious danger of extinction. On several occasions over the last few decades, the Owens pupfish have suffered losses by largemouth bass that find their way into the pupfish’s refuges, likely due to illegal releases by anglers.

Today the Owens pupfish hangs on in a small constellation of protected springs and marshes in the Owens Valley. The largest populations in Fish Slough may number in the thousands, but altogether the species occupies only a few acres of habitat. In 2021, biologists even created a new refuge population to give the fish another chance.

Additional material:

Oral history video featuring Phil Pister recounting his career and that fateful day.