The Man Who Saved the Owens Pupfish

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

Less than 2.5 inches in length, the Owens pupfish is a silvery-blue fish in the family Cyprinodontidae. 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.

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 ara 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.

William Mulholland

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.

One of those animals is the Owens pupfish.

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, and you get a recipe for disaster. And disaster is exactly what happened.

The remains of the Owens River flowing through Owens Valley in California. Credit: Erik Olsen

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 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, 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.

Edwin Philip Pister
Edwin Philip Pister

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 obituary, “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.

Pister had few friends among his fellow scientists. Known for being 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.”

Los Angeles Aqueduct. Credit: Erik Olsen

As 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.

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

Today, the Owens pupfish remains in serious danger of extinction. On several occasions over the last few decades, the Owens pupfish has suffered losses by largemouth bass that find their way into the pupfish’s refuges, likely due to illegal releases by anglers. In 2009, the US Fish and Wildlife Service estimated that five populations totaling somewhere between 1,500 and 20,000 Owens pupfish live in various springs, marshes, and sloughs in the Owens Valley, where they are federally protected.

by Erik Olsen

Additional material:

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

Read previous articles in the California Science Weekly.

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