Near the concrete banks of the California Aqueduct, a small hangar houses a series of tanks five feet in diameter. One day in July, Tien-Chieh Hung, an aquacultural engineer, peered over the side of one, and shined a flashlight into the depths of its temperature-controlled water.
A school of iridescent fish about as long as your pinky finger glided in and out of visibility. “That’s delta smelt,” Hung said, before quickly turning off his light and closing the tank’s fine-mesh cover. “They’re a sensitive fish.”
The hangar is part of the Fish Conservation and Culture Laboratory at the University of California, Davis. Hung directs the lab, where he and his staff manage two populations of cultured delta smelt. One of them is for research, and the other will serve as a refuge population when wild delta smelt go extinct.
Both the state of California and the U.S. Fish and Wildlife Service listed delta smelt as a threatened species in 1993; in 2009, California reclassified the fish as endangered. The latest estimates, from 2016, say the wild smelt population lies between 6,000 and 28,000 individuals. After its latest annual trawl survey, the California Department of Fish and Wildlife recorded a record-low number of wild delta smelt: zero. The refuge population at Hung’s lab represents one manifestation of Endangered Species Act efforts to protect the fish from extinction.
But outside the walls of the lab lies an environment increasingly unfit for fish like delta smelt. The Sacramento-San Joaquin Delta, some 40 miles inland from the San Francisco Bay, is a 1,100-square-mile tidal marsh that for millennia teemed with salmon, shellfish, tule elk, deer, and waterfowl — all of which supported a Native American population of about 300,000 people.
That all changed in the 20th century, when much of it was drained and diked for agriculture. The delta also became the heart of the state’s urban water supply. Nearly two-thirds of California’s population and 3 million acres of irrigated farmland depend on the delta for fresh water, according to the Public Policy Institute of California. Much of that water is pumped through more than 1,200 miles of pipes and canals by the Bureau of Reclamation’s Central Valley Project, which primarily feeds California farms, and the State Water Project that sends most of its water to urban areas in the Bay Area and Southern California. All told, about two-thirds of delta freshwater is exported to cities or irrigators.
In 2008, in accordance with the ESA, the U.S. Fish and Wildlife Service issued a biological opinion stating that this pumping system directly jeopardized delta smelt and other native fish listed under the act, including the winter-run chinook salmon. The order set a sort of speed limit on exporting water from the delta through those pumps and fanned the flame of a decades-long legal controversy over the delta’s dual roles as a living ecosystem and the state’s water supply hub.
That controversy persists today. Interior Secretary David Bernhardt, a former lobbyist for the state’s largest irrigation district, and President Donald Trump have issued proposals to ramp up pumping from the delta. And on August 12, the administration issued changes to the Endangered Species Act that would drastically reduce protection for threatened species like the delta smelt that are at odds with commercial projects.
“We’ve over-promised how much water we can safely export and deliver out of this watershed,” said Doug Obegi, a lawyer and director of California river restoration programs at the Natural Resources Defense Council. “No one wants to face the fact they are complicit in the decline and potential extinction of multiple species in the delta.”
The delta smelt spends its entire one-year life cycle within this estuary. Its decline has become a clear signal to many scientists and environmentalists that something is ecologically imbalanced in its environment.
“We’re taking this fish as an indication,” said Hung, as he walked between the tanks of his refuge population. Each year, the National Marine Fisheries Service permits Hung’s lab to collect 100 wild delta smelt to maintain genetic diversity of the refuge population. Most years, Hung’s staff finds 100 wild smelt, no problem. Last year, they could only scrounge up 28.
The decline of this small fish has forced many state and federal agencies, scientists, and water users to grapple with environmental protections in a landscape heavily altered for human use. The fish represents a murky yet familiar battle between protecting endangered species and maintaining an economic status quo. Or, as biologist Peter Moyle said, delta smelt have become the “scape fish” in California’s complex water wars.
In 1972, Moyle, a fisheries biologist from Minnesota, took a faculty job at UC Davis and began studying Hypomesus transpacificus. The young scientist eager to publish research saw the delta smelt as a blank canvas of academic inquiry. Other than basic taxonomy and the fact that it was endemic to the delta, little was known about the fish, and there was no indication that it would later swim into the center of California’s water politics.
In the ’70s, delta smelt were abundant. During his first year at UC Davis, Moyle joined a state trawl survey and noticed hundreds of iridescent smelt among the survey’s target catch of striped bass. Hardly visible in the delta’s turbid waters, the smelt gave off a scent like cucumber. Moyle was curious, and asked the state biologists to save some for him to study.
A few months later, a truck pulled up to Moyle’s lab, its bed full of boxes of bottled smelt. “They had saved hundreds of smelt for me,” said Moyle. “That should tell you how abundant the species was at the time.” In 1970, the state’s annual trawl collected 1,673 smelt, suggesting a total population in the millions.
In the decades that followed, Moyle became the premier expert on delta smelt. He and his students and colleagues filled in the blanks of the pelagic fish’s scientific literature, along the way discovering that understanding delta smelt was like reading the evolutionary story of the delta itself.
For instance, delta smelt are what biologists call “stroke-and-glide” swimmers. They swim up and down in the water column just enough to find a current and then glide with the tide as they feed on plankton, eventually finding an optimal place to spawn. Partly iridescent and partly transparent, delta smelt also blend into the turbid waters of the delta, helping them avoiding predators.
“It’s pretty remarkable actually,” Moyle said with a fascination unfaded by nearly 50 years of studying the species. “It’s a fish completely adapted to the estuary as it was before the Gold Rush.”
By their nature, estuaries are fluctuating ecosystems. In the case of the Sacramento-San Joaquin Delta, where much of the freshwater flows from the Sierra Nevada meet the active ebb and flow of the San Francisco Bay and the ocean beyond, the delta smelt filled an evolutionary niche; it is a species perfectly matched to its constantly changing home. “It’s a very dynamic environment,” explained Moyle. “And here’s this small fish that somehow managed to make it, surviving wet years and drought.”
But by the time Moyle started studying delta smelt, the stage had already been set for its decline.
In his book The Great Thirst, historian Norris Hundley, Jr. called California a “hydraulic society.” He was specifically referring to the C.W. Bill Jones and Harvey O. Banks pumping plants in the south delta. Integral pieces of the federal Central Valley Project and the State Water Project, respectively.
By the time the CVP and SWP pumps began operating in 1951 and 1966, respectively, the state was already well on its way to transforming half a million acres of tidal marsh in the delta into farmland by constructing around 1,500 miles of levees. These pumps would support the continued expansion of the state’s agricultural economy and its urbanization while decreasing dependence on groundwater in Southern California.
The idea seemed simple: Move the water to where there is none. With water deliveries, California’s arid regions didn’t necessarily need to be impediments to economic growth. This same idea made cities elsewhere in the West, like Las Vegas and Phoenix, possible, albeit those are dependent on a diminishing Colorado River.
A half-century of pumping later, the Sacramento-San Joaquin Delta remains the heart of the water supply for most of the state. California uses that water to produce two-thirds of the country’s fruits and nuts and a third of its vegetables, while the populations of both the Bay Area and Southern California rely in no small part on water diverted through the State Water Project. The drinking water for 25 million people comes from the delta. The plethora of pumps, dikes, diversions, dams, and canals arguably makes California, as Chris Austin phrased it in her encyclopedic water policy blog Maven’s Notebook, “the most hydrologically-altered landmass on the planet.”
The problem with this system of water use in the delta, said Moyle, is that “as more and more [water] gets appropriated for other purposes, there’s less available for fish.”
In the 1980s, a six-year drought delivered the final blow to populations of delta smelt and other native fish in the delta. Starting in 1986, Moyle noticed the smelt’s unique cucumber smell and iridescent glisten became steadily rarer in his survey catches. Then the fish disappeared from his surveys altogether. By the end of the drought, he and his students looked at the data of his and other surveys around the estuary and came to the conclusion that the delta smelt population had crashed.
Moyle and other biologists working in the delta would spend the next few years discovering various causes of the smelt’s decline, including competition with invasive species, chemical runoff from agriculture, and rising water temperatures. But Moyle’s primary concern was with the delta’s water delivery system.
“When you’re manipulating the water flow into and out of the estuary, you’re messing with the smelt’s habitat,” he said. “It really needs a living estuary.”
In 1989, Moyle petitioned the California Fish and Game Commission to list the delta smelt under California’s Endangered Species Act. He felt that delta smelt and other fish such as salmon and striped bass had gotten the short end of the stick for decades. Listing the species, he thought, might bring attention to the fish’s plight.
He was right, but it didn’t necessarily bring the attention he intended. When Moyle was invited to a meeting at the Fish and Game Commission concerning the delta smelt listing, he was “surprised to find the auditorium packed with representatives from environmental groups, state and federal agencies,” many of them concerned with the potential conflict between Endangered Species Act protections and the full operation of California’s vast water supply system.
Moyle remembers that one state official asked him if listing the smelt would mean reducing the amount of water exported through the pumps. “Yeah, it’s quite likely,” Moyle told him, to which he remembers the official responding, “Well, we can’t possibly list it then.”
“I realized right away that this [fish] could be trouble,” said Moyle.
In 1993, both the state and the federal governments listed the delta smelt as threatened. The conflict between the fish, farms, and cities ratcheted up another notch.
This is far from the first time the Endangered Species Act has sparked political controversy. Enacted in 1973, the ESA represents to many environmentalists what historian Dan Flores describes as “biocentrism’s ideal translated into legal language.” At its core, it aims to end human-caused extinction, granting hundreds of threatened and endangered species — from iconic bald eagles and grizzly bears to the relatively arcane smelt and salamanders — the basic right to exist.
Although the ESA says that listing a species should be based on the “best science available” rather than economic considerations, it didn’t take long for that ideal to be measured up against dollars and cents. In 1976, a lawyer named Zygmunt Plater sued the Tennessee Valley Authority in a bid to halt construction of the Tellico Dam, which posed a risk to an endangered fish called the snail darter. The Supreme Court two years later ruled in favor of the fish, saying in a 6-3 decision the dam’s construction violated the Endangered Species Act. The multimillion dollar dam by that time was a dozen years into its construction, and the ruling showed the ESA’s power. But, later that year, Congress amended the ESA to establish a committee of Cabinet-level members that could evaluate ESA regulations on a case-by-case basis. The Endangered Species Committee, nicknamed the God Squad, in 1979 overruled the ESA protections for the snail darter, and the Tellico Dam was built.
In the case of the snail darter, the fish didn’t stand a chance. In his book The Snail Darter and the Dam: How Pork-Barrel Politics Endangered a Little Fish and Killed a River, Plater recounted how politicians and the press said the case pitted a “stupid fish against the TVA.” Plater wrote that the Tellico Dam saga was “a case study of polarized politics, a powerful but imprudent press, and stalemated congressional procedures. Only in America could this kind of fish story happen.”
After Tellico Dam was constructed, remnant populations of snail darter were later discovered in a Tennessee River tributary, and the fish lives on, though on the brink. But, as journalist Christopher Ketcham wrote concerning the snail darter case, “Congress had set the stage for future interventions if and when the ESA undermined the prevailing economic order.”
Which brings us back to delta smelt. In 2008, when Fish and Wildlife released its biological opinion stating that the two delta pump facilities would need to slow down or the fish would go extinct, the fish took the heat.
In 2014, during one of the driest periods in California’s recorded history, Representative Devin Nunes, a Republican from the Central Valley, called the delta smelt a “stupid little fish” on the House floor, blaming the fish’s protection for causing a “man-made drought.” Nunes and many of the state’s irrigation districts blamed environmental regulations for the water shortage, going so far as to deny that California was experiencing a drought at all.
“This is not a drought year,” Harry Cline, the Fresno-based editor of Western Farm Press, wrote the year prior. A brief torrent of rain that November and December was allowed to bypass the pumps to protect the fish. In Cline’s opinion, “800,000 acre-feet of water went to waste based on the science of four buckets of minnows.”
According to Mike Wade, executive director of the California Farm Water Coalition and a former Merced County farmer, decreasing the water pumped from the delta isn’t doing good for farmers or the smelt. “The costs we bear as a society in terms of water supply impacts,” he said, should at least have something to show for it after 10 years of regulations. Instead, delta smelt continue to decline.
“I don’t know anybody who, with a straight face, can say that the Endangered Species Act is working,” Wade said.
But some say that the continued decline of delta smelt doesn’t necessarily reflect failures in the ESA. “It reflects failure in the implementation, not the law itself,” said John Buse, general counsel and legal director of the Center for Biological Diversity.
In fact, the delta smelt population rebounded in 2011, perhaps in part due to regulations. Then the drought hit, and scientists and attorneys like Buse and Obegi saw implementation of those regulations slide. “It’s like Steinbeck wrote,” said Obegi. “In the wet years, people forget the dry years.”
Either way, the “man-made drought” argument reached Donald Trump on the campaign trail in 2016. At a rally in Fresno, Trump condemned environmentalists for “taking water and shoving it out to sea” to “protect a certain kind of three-inch fish.” He promised Central Valley farmers that he would roll back the regulations that limited their water supply.
This year, President Trump has started to make good on that promise. In February, the Bureau of Reclamation released a plan designed to “maximize water supply delivery” and minimize regulatory burdens for irrigators in the Central Valley, despite the continued concerns of federal biologists that increasing deliveries would harm delta smelt and salmon.
The proposal represents just one example of the Trump administration’s various moves to weaken the Endangered Species Act, but this one sits closer to home for one member of Trump’s Cabinet. Earlier this year, a New York Times investigation found potential overlap between Interior Secretary David Bernhardt’s current appointment and his previous job as a lobbyist for Westlands Water District, which covers 600,000 acres of farmland in California’s Central Valley, making it the largest irrigation district in the United States. Analysts saw Bernhardt’s involvement in Trump’s proposal as a clear conflict of interest and a violation of the ethics pledge that Bernhardt signed when he was appointed.
On August 12, the Trump administration announced plans to change how the Endangered Species Act is enforced. Under the new guidelines, threatened species such as the delta smelt would no longer receive protections equivalent to endangered species, as is currently the case. Regulators could also factor economic assessments into listing decisions — a move experts say would doom many species, as it’s rarely a cost-effective move to halt dam construction or curtail pumping in the nation’s thirstiest state.
In a statement, Bernhardt framed the changes as a bid for transparency, and one that will better incentivize landowners to assist in species recovery. “I cannot stress enough that a more efficiently implemented act is more effective,” he said. “Clarifying what action should be considered during agency consultations will ensure that ESA implementation is more clear and consistent across agencies and even between our own field offices. By better showing our work to address concerns and lack of transparency, I believe we will build greater confidence in the legitimacy and lastingness of our decisions.”
But giving threatened species the same protection as those with endangered designations was a preventive measure allowing action to be taken before it was too late. And for many environmentalists, protecting an entire species is incomparable to short-term economics.
“It’s a moral concern: What right do we have to essentially cut off a branch of an evolutionary tree? What we have 5 million years from now will depend on what we have now,” Buse said. “I think people try to justify their position in economic terms. But even if we could quantify a species’ value, we can’t calculate that magnitude of loss if we’re basically relegating species to extinction…. We’re severing that evolutionary branch forever. The loss there is not calculable.”
The economic benefits of increased delta water deliveries could also belie the long-term resiliency of habitats these animals rely on. In fact, reducing water exports from the delta may be necessary regardless of the smelt’s fate. In 2017, the nonpartisan Public Policy Institute of California released a report explaining that, even without the presence of endangered species, exporting too much water risks increasing the overall salinity of the delta, essentially ruining it as a water source.
If the Sacramento-San Joaquin Delta isn’t suitable for delta smelt, the thinking goes, can it really remain suitable for humans? As environmental historian Peter Alagona describes in After the Grizzly: Endangered Species and the Politics of Place in California, the ESA not only insures that species can survive but, in a sense, provides an avenue to protect entire habitats. To preserve a species, one must preserve the places it calls home.
As California’s water wars play out, Moyle, Hung, and other scientists from state and federal agencies work to prevent the delta smelt’s extinction. Of course, there’s no silver bullet, particularly when the problem extends beyond the fish to the whole delta ecosystem. “It’s got to be a whole bunch of things simultaneously,” said Moyle.
Should wild smelt go extinct, the Suisun Marsh — the largest brackish wetland on the West Coast, at more than 116,000 acres — represents one possible location for reintroduction of delta smelt from Hung’s refuge population. Another discussed area is closer to Sacramento, at the Yolo Bypass Wildlife Area.
Recently, the Fish Conservation and Culture Laboratory began working with state and federal biologists to test if cultured fish could survive in these natural conditions. They put captive-bred smelt in cages and deployed them in various parts of the estuary for up to a month. In the first round of the project last January, when temperatures were lower, nearly all the smelt survived. Other effects of the study, like diet and potential contamination, are still being analyzed.
But Hung concedes that we’re a long way from any large-scale reintroduction. There are major concerns. For one, every generation of delta smelt in captivity represents one generation removed from its evolutionary niche, even as the lab continues to introduce wild smelt into the population. Among swimming, feeding, and spawning behaviors, there could be unforeseen signs of domestication between tank and ecosystem.
Hung is also concerned with the environment itself. If wild smelt go extinct in its heavily altered native ecosystem, what chance do his refuge smelt have at survival? According to Hung, summer water temperatures can approach 28 degrees Celsius in the nearby Clifton Court Forebay — an intake point for water pumped south. The water in his refuge tanks, in contrast, is 16 degrees.
“If the environment keeps getting worse, it doesn’t make sense to put the fish back,” he said.
The delta smelt has forced many people to reexamine how they look at the delta and to reassess its needs.
The fact that we’re here at all, with this little fish on the brink of extinction, should be sending red flags up all over the state, many advocates say.
“The Endangered Species Act is kind of the emergency room decision. It really kicks in when things are already in a lot of trouble,” said Obegi, the attorney at the NRDC. “The fact that the ESA had to be triggered here is really an indictment of our general failure to manage water resources sustainably for the decades leading up to those listings. When you get to the point when a species is listed, it gets harder and harder to reverse those trends.”
Many are calling for the state to reduce reliance on the delta as a water source. Louise Conrad, a biologist for the state’s Delta Stewardship Council, hopes that any reassessment looks far into the future. “We’re trying to forecast science and management needs on a longer time frame — longer than, say, normal political offices are,” she said. “That is where we need to be looking, the long game. What does the delta look like in 2100?”
Some just don’t want this fish to be forgotten. For Moyle, delta smelt are “part of our heritage. They represent what’s unique about California and the delta.” He continued, speaking broadly about endangered species: “They have as much right to exist as we do.”
And that right to exist, Hung argues, is entwined with our own. Once the ecosystem can no longer support delta smelt, it may fail for other species as well: longfin smelt, salmon, and perhaps, down the line, humans. “Other species,” he said, “will become the next delta smelt.”
