Up River

The Silvery Minnow Stares Down Another Dry Summer

Laura Paskus
10 min read
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With all this rain falling on the Duke City–the backyard vegetable garden is growing wild; the crabgrass in the front yard has been miraculously resurrected–thoughts naturally turn to … the silvery minnow.

For those who haven’t been riveted by the saga of the 4-inch-long endangered fish that tries to make its living in the Rio Grande, here’s a very short version of a ridiculously convoluted story: The minnow once lived throughout much of the river’s 1,850 miles. Thanks to dams, diversions, low flows, poor water quality and god knows what else, the minnow’s habitat is now restricted to a 157-mile stretch from below Cochiti Dam to just above Elephant Butte reservoir.

So how’s the minnow doing these days? New Mexico is no doubt experiencing dry times. The majority of the state is under a drought “warning,” with almost a quarter of the state experiencing a drought “emergency.” And it’s an undeniable fact that fish need water to survive. Even fish that live in rivers that flow through arid lands. The minnow did not evolve to deal with drought, as some have tried to point out over the past 12 years, as a lack of water in the Rio Grande has unfairly pitted the silvery minnow and the valley’s farmers against one another. Plain and simple: Fish need water to survive, and the Rio Grande is lately less and less of a river.

Without a Paddle

Left to its own devices, the silvery minnow would be long extinct. But since the river began drying more frequently and in longer and longer stretches, federal biologists have been making Herculean efforts to keep the fish swimming. In the spring, they collect minnow eggs, then propagate the fish in tanks. In the summer, when the river dries, biologists compete with birds and other predators–eager to snack on these easy targets dying in shallow pools–by scooping out the fish, then trucking them to wet reaches of the river. From fall through spring, biologists are at it again, stocking the river with the fish they raised in tanks.

Of course, things would be different if the Rio Grande–the state’s largest river–actually had water in it throughout the year. But thanks to diversions for irrigation, the river reliably dries each year after June 15, when water managers are no longer required to keep water between the banks of the river.

Since water managers are not required to keep the river flowing during irrigation season, early summer is undoubtedly rough on the minnow. This time of year, it’s not uncommon in Albuquerque to see more piles of trash and shopping carts than stretches of flowing water. (Don’t be fooled by the water flowing through the ditches or the low-flow conveyance channel. That’s separate from the riverbed.)

Thanks to this year’s bleakly dry winter, the river began drying earlier than usual: Biologists were already out on the river in March–they usually come out in May–salvaging minnows that would have otherwise died as the river dried. Until the rains fell in early July, biologists had spent 23 days out in the riverbed, rescuing more than 34,000 fish. All told this spring, almost 17 miles of riverbed dried, and biologists found nearly 2,000 dead minnows.

A Fish Out of Water

The recent rain sent biologists home from the river, but Mike Hatch, the Fish and Wildlife Service’s biologist who heads the minnow salvage operations, warns that those rains were a “short-lived event that will [only] buoy up the river for who knows how long.”

How well the minnow will do through the summer depends, he says, “on how the biology and the hydrology fit together in terms of choreography.” And, of course, he says, it also depends on whether or not there will be a reduced demand for irrigation water. In other words: Did farmers get enough water from the rain event that the Middle Rio Grande Conservancy District, which supplies water through acequias and ditches, can divert less water from the river this summer?

Unlike snowmelt, which swells the river over long periods of time and recharges groundwater supplies, these hard, fast storm events only benefit water levels in the short-term. So, while the rains helped backyard gardens and alfalfa fields green up and grow tall, they probably won’t affect the summer’s water deliveries to irrigators–the prime drain on the river. The Middle Rio Grande’s water delivery system actually plans on these storm events to supplement planned releases from upstream reservoirs. The recent rains, says David Gensler, the Middle Rio Grande Conservancy District’s hydrologist, “saved us a couple of weeks of water.”

“When we’re not in a drought, all those trickles of water out of the Jemez Mountains (and other wet spots in the higher country) keep the river propped up at a higher base flow than it is now,” he says. “We’ve been going through a drought period for 10 years or so. A week of rain, even a year of rain, isn’t going to get us out of it.”

So, no, the minnow’s probably not going to have a great summer, even though its population is actually higher right now than it was in recent years. The wet winter in 2005 carried the fish into this year, says Jason Remshardt, biologist with the Fish and Wildlife Service’s Fisheries Resources Office. But that “choreography” of biology and hydrology may not occur: The fish’s numbers are higher, but the river’s running lower. In other words, there may simply be more fish to die this summer.

And the Service is prepared to deal with that: Under the Endangered Species Act, which the Service enforces, a certain number of the fish are legally allowed to die. Called “incidental take,” in 2004, that number was 760. Last year, it was raised to 10,440. Now, the Service has raised it again to 265,935. That number, which was formulated by the Service’s Ecological Services Office, represents only fish that are actually found and counted; one scientist points out that it doesn’t include the fish that are eaten or otherwise disappear before biologists can tally their numbers. The actual number of fish that die is probably closer to 13 million.

Cashing Out

So, is all of this minnow management worth it in the long run? Without reliable flows in the river, scientists are forced to come up with more and more complicated ways of keeping the fish from going extinct. Every year, the Fish and Wildlife Service stocks the river with hundreds of thousands of minnows, hoping enough of them will survive to create a viable population in the wild. But some scientists say these inbred stocked fish are weakening the genes of the wild fish. Other scientists are looking at how salvage operations affect the fish. One study found that the rescue and relocation of minnows may be “fruitless” if drying pools are revisited several times when their water quality is degrading and if they are transported for long periods prior to release.

There’s no doubt that biologists involved with the minnow operations care about the work they do. Only people dedicated to the survival of the Rio Grande itself would be willing to work so diligently toward the survival of a 4-inch-long fish that’s treated like a sworn enemy of the nation, state and city of Albuquerque. What’s in doubt is why the powers that be continue to throw money at a problem that has only one real solution: a river with water between its banks.

Whereas lawmakers in New Mexico have been adverse to showing any support for the minnow’s need for water–with the notable exception of Rep. Tom Udall–they’ve been more than willing to spend money on the fish.

When conservation groups sued to keep water in the river to prevent the minnow from going extinct, Sen. Pete Domenici called the Endangered Species Act a “monster” and somewhat confusingly said it was being used to “artificially create a drought.” Although federal judges repeatedly ruled in favor of keeping water in the river for the fish, in 2003 Domenici introduced a rider that, among other things, invalidated the court decision. At the same time, however, Domenici has also funneled tens of millions of dollars toward silvery minnow projects. Because of him, Congress has funded the creation of working groups, artificial sanctuaries for the fish and salt cedar removal for habitat restoration.

Both Mayor Martin Chavez and Gov. Bill Richardson have opposed keeping water in the Rio Grande for the minnow, and both lawmakers decried the decision when U.S. District Court Judge James A. Parker ruled a few years back that water managers had an obligation to keep the river wet. Chavez said Parker’s decision “takes water from the mouth’s of the city’s children,” and Richardson flew to Washington, D.C. to seek help from former Interior Secretary Gale Norton in fixing the minnow problem. On the other hand, both the city and the state have set aside money for projects related to the minnow. And when it came time for the $1.7 million “refugium” for the fish to open at the Bio-Park in June 2003, Chavez and Richardson were both in attendance, with supportive words for the fish’s future. The new facility, said Chavez, “will help protect the Rio Grande silvery minnow from extinction by providing a place for the fish to spawn and grow in an environment that closely resembles its natural habitat.”

Today, another idea the Fish and Wildlife Service has devised is to reintroduce the minnow to a stretch of the Rio Grande in Big Bend National Park. Since this would be an “experimental” population that wouldn’t be protected, it presumably wouldn’t set off the same “fish versus farmer” wars that ignited in the Middle Rio Grande following the 1994 designation of the minnow as endangered. But some biologists believe such a move would siphon resources away from the Middle Rio Grande projects–and perhaps, in the long run, dilute efforts to protect the silvery minnow in the over-allocated Middle Rio Grande. As overdrawn as the river is today, the situation will only worsen as cities such as Albuquerque and Santa Fe get ready to use surface water to supplement shrinking aquifers.

Despite all the money from lawmakers and the hard work of biologists, the future doesn’t look exactly bright for the silvery minnow. So, really, what’s a minnow to do? Pray for more rain. Or perhaps, learn to fly.

Call 346-0660 ext. 247 or e-mail christie@alibi.com with news tips.

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