Can we save the Owens pupfish?

 

Advertisement

The Owens pupfish, a small blue fish native to the springs in the California desert, was spared from extinction on an August afternoon in 1969 by Phil Pister and his two buckets.

That day Pister, a state wildlife biologist, had heard that a marsh called Fish Slough, one of the few natural oases in the arid Owens Valley, was on the verge of drying up. The marsh, he knew, held the world’s last population of Owens pupfish. So he grabbed the buckets, jumped in his pickup truck and sped through ranchland toward water. The drive from his office in Bishop normally took 15 minutes; he did it in 10.

He parked in a cloud of dust, then he and a small crew hurriedly corralled 800 or so pupfish into mesh cages in the dregs of the pond. Afterward, he shooed his colleagues into town for dinner; he would finish up. But when he returned to the edge of the pool, he saw that the caged pupfish were dying, some already belly-up. By accident, he had placed the cages away from the oxygenated current, leaving the last Owens pupfish in the world to choke to death on air.

Distraught, he ran to his truck, grabbed the buckets and raced back. He scooped water and the remaining fish into the buckets, and drove to another spring to release the pupfish there. In the dark, with a heavy, sloshing bucket in each hand, he trudged across the flotsam of cow country — barbed wire, crumpled fences, rodent burrows — and under the white smear of the Milky Way. He thought of the Owens pupfish and wondered if anyone would care that he had saved them.

The origins of the Owens Valley

The story of the Owens pupfish begins millions of years ago, when freshwater lakes covered the western Great Basin, which holds the Owens Valley, in California. As the lakes shrank and disappeared, they left behind an aquatic archipelago — islands of water in the sand. In one of these isolated oases, the Owens pupfish evolved into a distinct species.

The Owens pupfish is a creature of extremities. In the summer, it can swim in waters warmer than 90 degrees Fahrenheit; in winter, it swims under ice. Females are olive-brown and males chalky blue, except during breeding season, when the males gleam a flamboyant blue.

“It’s ironic that they’re endangered,” said Steve Parmenter, a biologist now retired from the California Department of Fish and Wildlife. “They have a lot of characteristics of what would be a very successful, perhaps even invasive species.”

It would seem, then, that the Owens pupfish could survive anything. But in the 19th century white settlers began introducing invasive species, such as bullfrogs and bass, notorious pupfish predators. In 1913, the first segments of the Los Angeles Aqueduct were completed, diverting water from the Owens Valley to Los Angeles.

For the last 50 years, the Owens pupfish has flickered on the edge of catastrophe. The marshland that historically allowed the species to flourish continues to be drained and redirected hundreds of miles away and groundwater extractions sap the remaining springs. The descendants of Pister’s buckets still exhibit low genetic diversity, increasing the risk of inbreeding. Of the approximately 100 attempts to relocate the pupfish to new pools in the valley, almost all have failed.

The next 50 years look bleaker still. Climate change will likely shrink the snowpack in the Sierra Nevada that helps feed the springs. And the growing human demand for water will drain the pools further. Seven of the California’s native freshwater species are now extinct, and 82% of native species are highly vulnerable to climate change, according to a 2013 assessment.

Blinking in and out of existence

By the 1940s, when the Owens pupfish was formally described as a species, it was considered extinct. But in July of 1964, when Pister was still green on the job, he offered to give a tour of Fish Slough to ichthyologists Carl Hubbs and Robert Rush Miller to see if they could find any elusive survivors.

The three men wandered to a clear pool near a dirt track and looked down. Pister remembers Hubbs shouting, “Bob, they’re still here!” The other two rushed over, looked down and saw telltale iridescent flashes below the water’s surface: pupfish, each one no larger than an edamame pod.

The species had to begin again, from a population of fewer than 800 fish. State biologists worked to increase the pupfish population in new springs and maintain the sanctuary, but many of the new ponds succumbed to cattails or were stampeded by invasive bass.

After Pister retired in 1990, the pupfish torch eventually passed to a successor, Parmenter. “I was somewhat enamored of Phil and his thinking,” said Parmenter, who worked in recreational trout fisheries but had heard Pister speak before.

On the job, Parmenter found bass in many of the refuges and valiantly tried to extinguish the predators; just two bass could “hoover out” thousands of pupfish in a year, he said. He used traps, shocked the ponds with electricity and even hooked a few on a fishing line. But no sooner did he remove bass from one pond than he found others elsewhere, covertly introduced by recreational fishers.

He quickly learned that the best method of bass removal was a spear gun. “For a guy who went into biology because he likes animals, I get a diabolical satisfaction when I heard the thump of the murder of that fish,” Parmenter said.

After 1969, wildlife biologists transported tens of thousands of Owens pupfish to new locations, including the springs at Fish Slough, which had recovered its water. Nearly all these relocations failed within a decade, and many resulted in further winnowing the genetic diversity of the species. The relocated populations were often too tiny to be viable, losing alleles over time and through inbreeding.

“They’ve never really gotten out of the bucket,” said Nick Buckmaster, a wildlife biologist with the department who received the reins of the pupfish program — and an arsenal of spear guns — when Parmenter retired in 2020.

A possible new home

Buckmaster first learned about the Owens pupfish in college, when he was assigned to read an essay, “Species in a Bucket,” that Pister had published in Natural History in 1993. It helped inspire him to work in conservation.

When Buckmaster inherited the pupfish, the total area of all refuges occupied around one-eighth of an acre; the pupfish needed a lasting home. River Spring Lakes Ecological Reserve, a 640-acre swath of wetlands purchased by the state in 1980, seemed the best option.

But River Spring was overrun with what were presumed to be hybrid nonnative Death Valley pupfish. The tiny hybrids and their tinier larvae could easily slip through nets, and River Springs was too sprawling to drain. So with hundreds of sandbags, a crew of technicians dammed the spring into smaller wells, pumping out the water from each and removing the pupfish.

owens pupfish 

Over several winters, Rosa Cox, then a field technician for the department, led the removal with a crew of women. Nighttime temperatures dropped to 10 degrees Fahrenheit, and the women layered themselves like onions in thermals and waders. Every few hours they woke to ensure that the generator running the water pumps still ran in the biting cold. “It was emotionally challenging to be killing in very large numbers things that looked exactly the same as the species we wanted to preserve,” Cox said.

There were setbacks — several hybrid pupfish that escaped to once-cleared areas and left Cox in tears. (A few pupfish can quickly become 1,000.) She removed the last two survivors in the spring of 2020, electroshocking the pond just days before the town of Bishop went under COVID-19 lockdown.

Out of the bucket

With River Springs in the clear, the reintroduction of the Owens pupfish could begin. This April, a skeleton crew of biologists from the California Department of Fish and Wildlife and the U.S. Fish and Wildlife Service collected a few hundred fish from each of the refuge populations, put them in a cooler (no buckets this time) and drove them to their new habitat.

There, the biologists reunited more than 700 total pupfish from populations that had been separated for decades — the first chance the Owens pupfish had to become genetically diverse in a century. Formerly confined to pools smaller than living rooms, the fish now have several square miles of water with no predators in sight. The biologists hope this new home will finally sustain a flourishing population of Owens pupfish, with exponential growth over the next few years. “I breathed a sigh of relief,” Pister said.

Buckmaster and Cox returned several weeks later and found a school of more than 100 pupfish spawning. “I just can’t believe it worked,’” Buckmaster said.

River Springs marks a “great chapter in the saga of saving this pupfish from extinction,” Peter Moyle, a professor emeritus at the Center for Watershed Sciences at the University of California, Davis, wrote in an email. The pupfish will persist, he says, but only with constant vigilance. “A desert fish in living in limited habitats is never truly completely safe,” he added.

Every few days, Pister drives up to Fish Slough to check on his pupfish. Sometimes he brings lunch, a ham sandwich. He keeps a lookout for the other creatures that depend on the marsh, like raptors and Fish Slough springsnails — a native snail the size of a pinhead that is found nowhere else in the world. It has no lifeboat, no Phil Pister to ensure it will survive the next century. Some people wonder if such insignificant species are worth the trouble of saving; he does not.

 

 

 

 

Previous
Next Post »