The diminutive Delta smelt, no bigger than your pinkie finger, has for a decade been a heavyweight in California water politics.
When it landed on the federal endangered species list in 1993, the little fish posed a major roadblock to water exports south. Farmers fumed. Water managers threw up their hands.
Over the years, the fish helped spark a wholesale rethinking of how to manage the Sacramento-San Joaquin Delta, a key junction of California rivers and a vast network of pumps, canals and pipelines.
But could the smelt, once considered to be teetering on the brink, actually be out of danger?
Two influential Central Valley water agencies say the fish population has rebounded to such an extent that water deliveries no longer need to be restricted. They've launched a legal fight aimed at getting the Delta smelt removed from the endangered species list, putting them on a collision course with environmentalists.
At the heart of the fight are two gigantic delta pump stations. Those pumps, which send water flowing south to irrigate crops and water Southern California gardens, are also the prime culprits in the mass demise of the fish.
The smelt, less than 3 inches long, have a tendency in dry years to cluster around the pumps in the spring, when farmers are planting crops and most in need of irrigation water. As swarms of smelt draw near, the pumps have to be throttled back to keep the tiny fish from being sucked up and ground to bits.
Farmers say it costs them water they never get back.
During the spring of 2000, the government-run pumps delivered 257,000 acre-feet less water because of the smelt, said Dan O'Hanlon, a Sacramento attorney representing the Westlands Water District and the San Luis & Delta-Mendota Water Authority. In the spring of 2001, the cutback was 277,000 acre-feet.
In short, the tiny fish has been "a water manager's nightmare," said Steve Hall, executive director of the Assn. of California Water Agencies. "It came out of nowhere and -- boom! -- we have a fish that can't be screened out, can't be avoided because it lives in the delta. It was the poster child."
Removing the fish from the endangered species list, and giving water managers a freer hand to operate the pumps, O'Hanlon said, would help remove "this cloud of uncertainty" that hangs over farmers in particular.
"It's a bottleneck," lamented Jim Snow, Westlands' water policy chief. Some of the Central Valley farmers he serves "aren't sure the price they're having to pay is really doing good for the fish."
Biologists and statisticians hired by the agencies to study the smelt came to the conclusion that the federal listing was in no small part a result of drought in the late 1980s and early '90s that devastated the fish.
When wet winters returned, they argued, the population bounced back. By one estimate, there may be as many as 18 million of the fish in the delta.
Two lawsuits were filed in Fresno and in Washington, D.C., late last year asking the U.S. Fish and Wildlife Service to conduct a status review, which is required by law but hadn't even been started.
O'Hanlon said the hope is that the review will reveal that the smelt is no longer threatened with extinction. Negotiations are underway to settle the lawsuits, and O'Hanlon said a resolution could be reached fairly soon.
Although a new study of the fish might not seem an unreasonable request, environmentalists say they are worried because of the Bush administration's track record. In several recent California cases, it has declined to defend endangered species or their habitat.
"Our fear is that the administration is not going to take into account the best science," said Michael Wall, an attorney with the Natural Resources Defense Council in San Francisco. "We fear they'll determine this fish doesn't need protection, despite substantial threats to its survival."
Biologists who know the smelt best say it's almost certainly too soon.
The smelt typically lives only about a year, though some survive into a second season.
An eye-catching little fish, with an almost translucent steely blue sheen on its sides and a distinctive cucumber fragrance when plucked from the water, the smelt isn't a powerful swimmer. It can easily fall prey to the pumps, which actually reverse the flow of the winding waterways snaking through the delta's 550,000-acre triangle of wetlands and rich farmland.
Predators such as striped bass often congregate at the pump stations, waiting for schools of smelt to roll in and provide an easy meal.
Kevin Fleming, a California Department of Fish and Game senior biologist, said the fish is inevitably just a few bad seasons away from a crash because of its short lifespan. Though the population surged through the late 1990s, it crashed this past year, plummeting 90% from its peak in 2000, Fleming said.
"When you're talking about a species that lives primarily one year, it doesn't take long for a downward trend to translate into a significant reduction," Fleming said. "From what I've seen so far, it still looks like an endangered species."
Peter Moyle, the UC Davis professor of fisheries biology who played a key role in winning federal protection for the smelt, agreed that it is too early to take it off the endangered list. He worries about dire scenarios, such as a decadelong drought.
But in general, Moyle says biologists and water managers can work cooperatively to avoid pumping cutbacks that deny water to the south.
Ultimately, the smelt's status could be decided by officials such as Mike Fris, endangered species division chief for the U.S. Fish and Wildlife Service's Sacramento office.
Fris isn't offering any predictions, but he sees the possibility of doing an exhaustive review of the smelt's status as a healthy part of a process.
Although water managers and biologists have feuded often over the smelt, Fris said the warring parties lately have worked cooperatively to boost the export of water without hurting the fish.
"We have a duty to list an endangered species, but also to delist when necessary," Fris said. "I just wish we have definitive answers, so there would be no question and no debate. But it's never that way in biology."