“The delta smelt is on the brink of extinction,” says Doug Obegi, a senior attorney for the Natural Resources Defense Council in San Francisco. “This species, which is considered the bellwether of the health of the estuary, has fallen to the point where it can hardly be found anymore.”
The figures arrive just as the Trump Administration is proposing to loosen Endangered Species Act protections for fish in order to “maximize water deliveries” to users south of the delta—that is, farmers—according to a Dec. 29 announcement by the Interior Dept.
Obegi’s point about the smelt’s role as a bellwether is important. We care about the delta smelt not entirely for itself, but because its health is an indicator of the overall health of the delta ecosystem—and the signal it has flashed is alarming. We are facing the harvest of a half-century’s failure to fashion a statewide water policy that serves all the state’s residents—farmers, fishermen, city dwellers, and wildlife.
“This isn’t a battle between the delta and Southern California,” says Bill Jennings, chairman of the California Sportfishing Protection Alliance. He points to the development of water-hungry crops in the central valley, as well as a history of undervaluing the delta as merely an ecosystem, rather than a contributor to the state’s economy on many levels. “Healthy rivers and estuaries are a public trust, and we’ve never gone through a formal balancing of the public trust,” he said.
As an estuary, a transition zone where fresh- and seawater meet, the delta is particularly vulnerable to environmental changes that shift the balance of inflows and outflows.
Diverting too much of the freshwater supply to serve downstream farms and urban users allows more brackish water to infiltrate deeper into the delta, placing more stress on freshwater fish such as the smelt, but also on the species that traditionally feed on them, including shad and striped bass. Saltier water ruins agricultural productivity in the delta itself, and has contributed to a series of crashes in the chinook salmon population that has all but destroyed the commercial salmon fishery; last year, fishery authorities closed 200 miles of the West Coast to ocean salmon fishing to protect dwindling populations of chinook.
The diversion of water by itself isn’t the cause of the declining fish populations. The delta also has been afflicted by the invasion of non-native species such as the Asian clam, which arrived from China and Japan via ballast water dumped from ocean going vessels and competes with native fish for plankton, their food supply. Return flows from farms into the delta carry a load of toxic chemicals.
“It’s always hard to separate out water as the sole factor causing the decline,” says Peter Moyle, an emeritus professor of biology at UC Davis and an expert on wildlife conservation.
But low environmental flows exacerbate other factors. And those can be traced in part to the advent of the State Water Project in the 1960s and 1970s, along with the older federal Central Valley Project. Through a series of complex agreements, the dams and aqueducts of these projects aimed to transfer water supplies from their natural courses in Northern California to users elsewhere in the state.
The resulting legacy of conflict has been neverending: Those on the receiving end of the transfers tend to see them as theirs by right, even though they’re often constrained by regulations and senior legal rights belonging to others. The situation has not been helped by extended periods of drought, including a five-year dry spell, possibly related to climate change, that ended with a wet 2017. But a seriously dry winter thus far may herald the drought’s return.
Amid this turmoil the unassuming delta smelt was taken up by farmers and their political backers as a symbol of how environmental regulations “waste” water that could better be used to grow crops.
“To protect smelt from water pumps,” the Wall Street Journal editorialized in 2015, “government regulators have flushed 1.4 trillion gallons of water into the San Francisco Bay since 2008.” In fact, the Journal has so assiduously attacked the delta smelt that one might almost consider its editorial board to be among the fish’s most dangerous natural predators.
The Journal’s allusion was to a 2008 biological opinion by the federal Fish and Wildlife Service that operations of the Central Valley Project threatened the survival of the smelt, and therefore needed to be reconsidered. (The biological opinion was upheld in 2014 by a federal appeals court.)
But the fate of the smelt itself is a distraction; the real issue is the fate of the delta. And the decline of the smelt tells us it’s in trouble. While it’s true that agricultural production in Tulare and Kern counties, which receive water from the delta, is valued at more than $13 billion a year, that has to be weighed against other values needing to be preserved. They include the value of delta farming, commercial and sport fisheries, the health of its residents and their property values.
The possibility of the delta smelt’s extinction may not mean that the delta ecosystem is in irreversible decline. Populations of striped bass and American shad, among other species, recovered somewhat during the wet 2017, though the numbers still are lower than their heyday in the 1980s. Some experts say that bass and shad should become the new bellwethers of delta health, since smelt have become so sparse they can’t even fill that role anymore.
“This fish draws so much attention not because they are an indicator of the health of the ecosystem. That will affect not only the delta smelt itself, but other species, and even the health of humans,” says Tien-Chieh Hung, director of the fish conservation and culture laboratory at UC Davis, which is trying to cultivate a population of delta smelt for possible restoration in the wild some time in the future.
But protecting the smelt reflects another human imperative. Since the the Endangered Species Act was signed into law in 1973, Hung says, “no fish has gone extinct. We don’t want this to be the first one.”