DAVIS — Some wits have dubbed it the “smelt hotel” and the Delta smelt that live in tanks there might play a role in easing the state’s water wars.
Turbidity. Salinity. Temperature. These are just some of the factors that can mean life or death for a tiny fish that has become a major force in Sacramento-San Joaquin River Delta water controversies simply by dying off and becoming rare.
Nann Fangue and other researchers gather information inside a small building with a concrete floor about two miles from the main UC Davis campus. Tanks and plastic pipes take up much of the space. The fish smell is strong and the sound of circulating water is dominant.
Fangue’s smelt guests are extremely delicate, to the point that netting them to move them around must be done in a way that doesn’t expose them to air.
“They’re one of the most sensitive if not the most sensitive species you can work on in the lab,” Fangue said. “They are definitely not cooperative like salmon and trout.”
The 3-inch-long Delta smelt can be found in Solano County bays and sloughs, as well as other parts of the Delta. Now Solano County’s fish is rocking California’s water world.
Other rare fish with Endangered Species Act protections live in the Delta. Among them are the Sacramento splittail, the longfin smelt, the Central Valley steelhead trout and the green sturgeon.
But the Delta smelt has become symbolic of the Delta’s problems. The native fish has seen its population plummet, leading to well-publicized court decisions to restrict water exports to farms and prompting efforts to restore vast amounts of tidal wetlands in eastern Solano County.
“For better or for worse, the Delta smelt is one of the drivers of this,” said Peter Moyle, a fish biology professor in the Department of Wildlife, Fish and Conservation Biology at UC Davis and associate director of the UC Davis Center for Watershed Sciences.
Moyle has studied California freshwater fish for more than 40 years. The 1993 U.S. Fish and Wildlife Endangered Species Act ruling that proclaimed the Delta smelt as threatened refers extensively to Moyle’s studies.
The Delta smelt doesn’t have the best reputation in the Central Valley in such places as Tulare County. Some there blame court-ordered water restrictions related to protecting the fish for the fallowing of tens of thousands of acres of farmland and the loss of jobs.
Rep. Devin Nunes, a Republican representing the Fresno-Tulare areas, in a 2009 article in The Wall Street Journal, protested what he called a “regulatory mandated drought.” He called the Delta smelt “a 3-inch bait fish.”
There’s another way to look at the Delta smelt.
“It’s a species we should be proud of, because it only occurs in the Delta,” Moyle said.
People can argue that the smelt is unimportant and wouldn’t be missed if it disappeared, Moyle said. But, because it is so sensitive, it is a good indicator of whether the habitat is good for native fishes and invertebrates, he said.
In that sense, the Delta smelt could be a kind of early warning system, with its possible demise a harbinger of still worse Delta environmental damage to come.
“It is a species that is right in the middle of things,” Moyle said.
Scientists have tried to discover reasons for the smelt’s decline, be it fish getting killed in the water export pumps, smelt habitat getting saltier because of water exports, the presence of invasive species and pollution, or some combination of factors.
“The amazing thing to me is that it’s still out there,” Moyle said. “It still seems to be finding a way to survive. I think we’ve been lucky so far, it’s maintained itself.”
One rescue idea would make the smelt Solano County’s fish in a big way. Tens of thousands of acres in the rural, eastern county could be restored as tidal wetlands to create a hoped-for haven for Delta smelt and other rare creatures.
Knowing more about the smelt could make it easier to design restored wetlands best-suited to the fish. The work at UC Davis could help provide answers.
UC Davis breeds Delta smelt in Contra Costa County for research. Researchers at the “smelt hotel” in Davis then must find ways to keep smelt thriving at different life stages. It isn’t easy.
For example, smelt are a schooling fish and like large, open spaces, so small tanks are unnatural to them, Fangue said. The larvae dislike being in clear water.
“There’s all of these really subtle things you have to get right before you can even think of starting to do the manipulations we like to do,” Fangue said.
Delta smelt are delicate in many ways. They spawn once a year and have a one-year life span.
“If they have a bad year, that’s a pretty dangerous thing for the species,” Fangue said. “It makes it harder for them to recover.”
Fangue didn’t grow up with aspirations to save the Delta smelt. She is a fish physiologist who took over a lab for a fish physiologist who studied Bay-Delta issues, with the smelt on the to-do list. Federal and state agencies are particularly interested in the smelt.
So Fangue and other researchers for about two years have put smelt in the tanks to see how well they do in different temperatures, turbidities and other factors at different stages of their lives.
What works in the “smelt hotel” could work in the real world as well. It could help save a fish that is at the heart of the state’s seemingly endless water wars.
“A lot of my work before was interesting, but it didn’t have a direct application,” Fangue said. “Here you really feel you’re not just doing science, but people are paying attention.”
Reach Barry Eberling at 427-6929, or [email protected] Follow him on Twitter at www.twitter.com/beberlingdr.
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