The diminutive Rio Grande silvery minnow is in trouble.
When fish biologists conducted their fall census in October, they didn’t find a single minnow at the 20 sites between Bernalillo and Elephant Butte Reservoir where they’ve been routinely counting the endangered fish, the first time that has happened in 20 years of study.
That doesn’t mean no fish remain in the river, according to Fish and Wildlife Service biologist Jim Brooks. Subsequent sampling in November found stragglers, but not many.
“There’s still not a lot of fish out there,” Brooks said.
In response, water managers are scrambling to find a way to maintain wild populations of the minnow, at the heart of environmental and water management battles for nearly two decades, in 2013.
But even as the imperiled fish faces the risk of a potentially devastating third year of drought, government agencies are locked in a thus far fruitless search for a new way of managing the New Mexico waterway in the face of dry conditions and rising human demand.
The goal, said Mike Oetker of the U.S. Fish and Wildlife Service, is “to get water delivered to the people who need it, while at the same time helping to recover the species.”
From a biological perspective, the bottom line is simple, said Brooks: “If you don’t have water in the river, you don’t have fish.”
But with farms and cities diverting water from the river to meet their needs, leaving enough for the fish and the ecosystem on which it depends while at the same time meeting human needs has become an increasingly contentious issue.
“Water drives the economy,” explained Estevan López, head of the New Mexico Interstate Stream Commission.
How to strike the balance is the subject of discussions under way, largely behind closed doors, among the Fish and Wildlife Service, the Bureau of Reclamation and the Army Corps of Engineers. The agencies are working against a March 1 deadline, when the current 10-year plan for managing the river under the federal Endangered Species Act expires.
The water agencies appear intent on finding a way to keep the species alive and encourage its recovery even during periods with lower flows in the river than we see today. Critics contend that is unrealistic – that the Rio Grande’s human water users need to learn to do with less, so that more water can be left for the river.
Saving an ecosystem
In its natural state, the Rio Grande wandered a vast floodplain through central New Mexico, sometimes flooding during big spring runoffs through what is now Albuquerque, from east mesa to west. The Rio Grande silvery minnow evolved in that environment. During dry years, it would hang out in backwaters left behind, even as the river’s main channel dried, and then explode in population during wet years.
“This is a fish that evolved in a desert river,” said Mickey Porter, a fish biologist with the Army Corps of Engineers.
Then, when conditions are right, a female Rio Grande silvery minnow can produce 3,000 to 6,000 eggs in a single spawning season.
“These fish can go from zero to 60 pretty quick,” said Brooks.
Well-adapted to the old ways, the silvery minnow once lived up and down the Rio Grande and its key tributaries, from the Rio Chama all the way to the Gulf of Mexico.
Dams, levees and water removed from the river for farms and cities have changed all that. Dams block the fish’s ability to return after dry spells to places it used to live. Levees have allowed humans to build farms and cities in the floodplain, at the expense of the old backwaters where the minnow used to find refuge. And farms and cities have left less water in what remains of the river.
With the fish’s population plummeting, remaining only in a central New Mexico stretch of the river, the Fish and Wildlife Service in 1994 declared the Rio Grande silvery minnow “endangered.”
Signed by President Richard Nixon in 1973, the Endangered Species Act was a key element in a wave of federal legislation aimed at protecting the environment. At its core was the act’s finding that “various species of fish, wildlife, and plants in the United States have been rendered extinct as a consequence of economic growth and development untempered by adequate concern and conservation.”
The law focused not solely on the preservation of species at risk of extinction but outlined a broader purpose: “to provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved.”
That goal – conserving the ecosystem, not merely the species – is at the heart of the struggle over how to meet the minnow’s needs, in which the minnow has become a proxy for efforts to save the Rio Grande as a flowing river through central New Mexico.
“If we didn’t have the fish out there,” said Fish and Wildlife Service assistant regional director Michelle Shaughnessy, “you probably wouldn’t have water out there.”
And without the minnow, scientists say, predators up the food chain – larger fish and birds that depend on them – would follow.
“That’s why it’s so important to keep those fish out there in the river,” said Doug Tave, a biologist with the Interstate Stream Commission, “because the rest of the ecosystem depends on them.”
Managing with less?
In the past decade, the federal government has plugged the gap between dry year flows and the needs of the minnow by buying under-used water imported to the Rio Grande Basin from the headwaters of the San Juan River via the San Juan-Chama project. Since 1997, the Bureau of Reclamation has spent $39.4 million for such water. But much of that water came from surplus allotments owned by the cities of Santa Fe and Albuquerque. That solution has avoided some of the “fish versus farmers” conflict that has characterized Endangered Species Act fights on other Western rivers, because once it meets river flow targets for the fish, the water is available for downstream users.
With Santa Fe and Albuquerque now using their San Juan-Chama water directly, water managers acknowledge there is no longer enough extra water available to deal with the problem that way.
“We’re not going to have the luxury of just being able to run a lot of water down,” said the Interstate Stream Commission’s López.
Instead, water managers have focused on a series of measures aimed at making better use of the water remaining in the river for the benefit of the fish.
At an October meeting, a group of federal, state and local water managers settled on a list of 15 possible strategies with the potential of helping the minnow. They range from holding back a pool of water in storage to use during drought years to changing the timing of releases from New Mexico dams to meet the timing of the minnow’s greatest need for water to support annual spawning.
Absent from the list is any significant new source of water to leave in the river.
Given the minnow’s continued decline, even with the extra water the federal government has added over the last decade, environmentalists are skeptical.
“How’s the fish doing?” John Horning of the Santa Fe group WildEarth Guardians asked rhetorically during a recent interview.
Horning and others, in a recent white paper, argue that the only viable solution is the “reallocation of water to nature.” They argue for greater water conservation and efficiency efforts, with the water saved left in the Rio Grande as a way of increasing river flows above their current levels.
Horning also advocates a solution that has been used on other rivers – voluntary programs in which farmers are paid to leave a field unplanted during dry years so the water can be left in the river to meet environmental needs.
But the failure to reach agreement on these issues before now, despite years of talks and with a March 1 deadline looming, does not bode well for river management in 2013, said Valencia County farmer Janet Jarratt.
“We know we’ve got trouble coming next year,” she said.