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Last Chance to Save the Delta Smelt?

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The tiny, controversial Delta smelt | Photo: USFWS

California’s most controversial threatened species, the Delta smelt, has never been closer to extinction, but a state agency that could help it with the stroke of a pen is failing to do so.

That’s according to a group of environmental organizations that are pleading with the State Water Resources Control Board (SWRCB) to force aqueduct operators to leave enough fresh water in the Delta for the smelt.

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The Delta smelt, a three-inch fish that once numbered in the millions in the Bay Delta area, is in trouble for many reasons. Invasive species increasingly compete with smelts for food. Other invasive species eat the smelts. Pollution from much of California eventually drains into the Delta, where it can injure smelts and other wildlife.

But the biggest problem facing the Delta smelt is, at least in an engineering sense, the easiest one to end: the giant pumps that suck Delta water into the federal Central Valley Project and the State Water Project. The pumps have several effects on the Delta ecosystem, but most critically for the smelt they reduce the amount of fresh water flowing through the Delta into the Bay. That lets seawater come farther into the Delta at high tide. And that is bad for the Delta smelt, which thrives only in a relatively narrow range of salinity. The smelt stick to a slightly salty “mixing zone” where there’s about 17 gallons of freshwater for every gallon of saltwater.

Without diversions, that mixing zone shifts with the tides and the seasons, but the smelts can generally cope with that. With diversions, especially in a drought year, the mixing zone moves far inland, drastically narrowing the band of salinity acceptable to the Delta smelt.

Why is the threat from pumping "easy to end?" Turn off the pumps, and in a short time whatever water is available in the Sacramento starts flowing out to the Bay again. Of course, that's only easy if you ignore the politics.

Earlier this month, the Natural Resources Defense Council (NRDC), Defenders of Wildlife, and the Bay Institute sent a letter to SWRCB urging the agency to enact emergency regulations requiring the federal Bureau of Reclamation (BuRec) and the California Department of Water Resources (DWR) to cut summer pumping of Sacramento River water into the aqueducts of the Central Valley Project and the State Water Project in order to protect the smelt. The groups, which charge that SWRCB is legally obligated to protect the smelt and other threatened species in the Bay and Delta, wants the Board to force the aqueduct operators to reduce pumping until the end of September to protect the Delta smelt’s brackish habitat.

So far the Board hasn’t acted, despite pleas by state and federal wildlife agencies for increased water for the smelt. NRDC and the other groups are essentially asking the Board to follow the law. “We know what to do to save the Delta smelt,” said Kate Poole, a senior attorney at NRDC who directs the organization’s Wildlife and Water program. “We just need to take steps to do it.” 

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The Delta smelt's fate is in our hands. | Photo: USFWS/John Ridilla

The SWRCB is legally required to protect the Delta smelt under the California Endangered Species Act; the fish is on the state’s Endangered list. The Delta smelt was also listed as Threatened under the federal Endangered Species Act in 1990; an attempt to downgrade its status to Endangered failed a few years back, when the U.S. Fish and Wildlife Service placed the smelt on its “Warranted but Precluded” list. That means USFWS agrees the Delta smelt ought to be listed as Endangered, but other species in more trouble are ahead of it in line.

It’s hard to imagine how much more trouble a species could be in without already being extinct.

Precluded or not, the Delta smelt has never needed the water more. Its numbers have dropped catastrophically in the last two years, and fisheries biologists are holding meetings at which they ask whether the smelt’s extinction is inevitable.

Until this year, Delta smelt population estimates have been very rough guesses. Smelts are hard to count: they’re small, they’re distributed throughout a maze of channels, sloughs and shallows, and they prefer murky, sediment-laden water. Biologists have historically conducted a series of sampling trawls throughout the year, counted the smelts in the nets, and then released those numbers — and how many smelt went unsampled was more or less anyone’s guess.

But a new set of mathematical models developed by statistician Ken Newman now allows biologists to take the number of fish sampled in trawls, the amount and quality of available habitat, and other factors to calculate more reliable estimates of smelt numbers. Using historic trawl results gave researchers a glimpse into how the actual population of smelts has changed over the decades. And doing so revealed a stark recent decline for the Delta smelt.  In early 2015, the U.S. Fish and Wildlife Service estimates, there were around 112,000 adult Delta smelt remaining in the Delta, an all-time low.

By mid-2016, that had dropped to around 13,000 Delta smelt.

The decline is stark enough, and the ongoing drought bad enough, that on August 2 BuRec and DWR asked the Fish and Wildlife Service to redraft a controversial document required by the Federal Endangered Species Act governing how the two agencies must operate their respective aqueducts to protect the smelt. That document, known as a Biological Opinion or “BiOp,” details restrictions on how many smelts the projects are allowed to harm in the course of normal operations, and measures the agencies must take to reduce that harm.

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From the Sacramento River to the Mojave Desert via the California Aqueduct | Photo: Raymond Shobe, some rights reserved

That’s not a step the aqueduct operators would take lightly. The existing Delta smelt BiOp, along with a related BiOp governing salmon in the Sacramento River, was the object of protracted and bitter court battles from the moment its first draft was released in 2005. NRDC sued USFWS over that first draft, saying it understated threats to the smelt, and then Central Valley farm interests sued over a 2008 update that said water diversions were a significant threat to the species.

I wrote about that long, complicated battle in 2014, after the Ninth Circuit Court of Appeals finally upheld the 2008 BiOp. That’s almost a decade of litigation, and just two years after the final appeals court decision the aqueduct agencies are asking for the BiOp to be redone. Given the degree to which farming interests have bitterly opposed preserving the Delta smelt if it means a slackening in the rate at which their profits increase, you can be sure that those interests will drag the new BiOp into court if it comes even close to doing an adequate job of protecting the Delta smelt. BuRec and DWR cite dwindling smelt numbers and continuing drought as the reason for their move. The agencies are also asking the National Marine Fisheries Service to redraft the salmon BiOp, likely with a similar response forthcoming from ag interests.

Neither BuRec nor DWR responded enthusiastically to this year’s pleas by USFWS and CDFW for the aqueduct operators to leave more water in the Delta; they met the bare minimum requested on just 10 days since June 1, and have announced that they won’t provide any extra water for the smelt until the end of September. The request for a new smelt BiOp might thus seem a bit incongruous. It may be that BuRec and DWR fear lawsuits from their customers if they comply voluntarily with those requests for more water, and are asking for a new BiOp to give themselves cover.   

Local environmental groups, meanwhile, are pushing for stronger protections for the fish. “We hope that Federal agencies will tighten the environmental restrictions on the pumping stations,” said Barbara Barrigan-Parrilla, executive director of the group Restore the Delta. “We are too close to the edge of collapsing the entire estuary if we don't put more water back into the system.  Fish need clean water in adequate quantities, as do the four million Delta residents whose drinking water, public health and economy depend on a healthy estuary.”

Regardless of which direction the new Biological Opinions take, it will likely be many months before a draft is ready for public examination. (It will likely be gargantuan and forbiddingly complex.) In the meantime, BuRec and DWR will continue to operate their pumps under the terms of the 2008 BiOp.

The thing is, under the terms of the 2008 BiOp, Delta smelt numbers declined by about 90 percent in just the last year. Which means that unless the State Water Resources Control Board acts on the NRDC et al’s request, that BiOp may be published well after the it could do the Delta smelt any good.

For ongoing environmental coverage in March 2017 and afterward, please visit our show Earth Focus, or browse Redefine for historic material.
KCET's award-winning environment news project Redefine ran from July 2012 through February 2017.

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