07-08-2006, 09:32 AM
Drought Threatens the Rio Grande Cutthroat
[img2="left"]http://ndis.nrel.colostate.edu/plugins/spx/images/010577a.jpg[/img2]Drought Puts Native Fish in Danger
By John Arnold
Albuquerque Journal Saturday, July 08, 2006
JEMEZ SPRINGS, N.M. (AP) -- Chuck Dentino hovered over a small pool of stagnant water on the Rio de las Vacas and watched a few small fish dart from one end to the other.
They had nowhere else to go.
The stream bed that meandered above the 10-foot diameter pool and below it was bone dry for as far as the eye could see.
"The only thing holding water are these pools," said Dentino, a fisheries biologist with the U.S. Forest Service. "It's the last place the fish have to hang out."
Had it not been for a 2004 Forest Service habitat restoration project that created a series of pools along the Jemez Mountain stream, there would in fact be no place for fish to survive.
Record drought is taking its toll on northern New Mexico's high country waterways, some of which are "drying up like mad," according to Dentino.
Reduced water flows are in turn threatening dwindling populations of the native Rio Grande cutthroat trout -- the state fish -- that biologists and conservationists have been working hard to save.
The species, which over the years has been hybridized by nonnative rainbow trout and increasingly pushed out of its habitat by nonnative brown trout, now occupies less than 10 percent of its historic range.
The Forest Service, the state Game and Fish Department and conservation groups are working to improve former cutthroat habitats in hopes of repopulating them with fish from other streams.
But according to Mike Maurer, president of the conservation group New Mexico Trout, the ongoing drought is creating a bleak situation for the existing populations.
"They may not be there to move," he said.
New Mexico's pitiful snowpack last winter is largely to blame. Spring runoff that typically recharges channels and flushes choking sediment from the water practically was nonexistent, Dentino said.
Lack of snow affects streams in other ways as well. Snow usually blankets water channels and provides thermal protection. Without that protection, streams can freeze solid.
Federal and state fisheries officials don't yet know the extent of the drought's impact on Rio Grande cutthroat populations, but they're working to find out.
Earlier this month, Dentino's team surveyed a 1,000-meter stretch of the Rio Puerco, another Jemez Mountain stream, and couldn't find a single fish. A similar survey last year revealed 285 Rio Grande cutthroats along the same section of river.
Southeast of the Rio Puerco, monitors are keeping a close eye on the Canones and Polvadera streams, two more vital cutthroat habitats that so far appear to be holding up to the drought.
But both "are extremely important to the survival of the species, and the conditions over there are pretty ripe for a disaster," said Sean Ferrell, a Forest Service fisheries biologist.
According to the National Weather Service, Jemez Springs received a little more than an inch of precipitation between November and May, the lowest level reported in 90 years of record-keeping there.
Conservationists acknowledge that droughts come and go, and that fish populations have endured them in the past. But the severity of this year's dry spell, coupled with habitat degradation, is making it harder for populations to survive, they say.
Land management practices over the past century have resulted in denser forests, more roads, grazing and disappearing wetlands, all of which impact stream habitats, according to Ferrell.
Catherine Sykes, the state Game and Fish Department's assistant chief of fisheries, said that in some cases, her staff must let nature take its course.
But, she added, there are critical populations of Rio Grande cutthroats that the department can't risk losing.
Government biologists and private conservation groups monitoring Peralta Creek have been discussing capturing and moving populations in the creek east of Jemez Springs. But such an operation is expensive and technically challenging. Biologists must first conduct tests to ensure the genetic pool of the endangered population is pure.
If it's not, and hybrid fish are mixed with pure cutthroats, "then you would undermine the gene pool you're working so hard to preserve," said Arnold Atkins, vice president of Trout Unlimited's Truchas chapter.
Biologists and conservationists are hoping for productive summer monsoons to get parched streams running again. The seasonal moisture typically begins in early July.
"If the monsoons do come, and we get some good rain, they should be OK," Maurer said. "They should survive, just like they have for centuries.”
Article Courtesy of the Albuquerque Journal at www.abqjournal.com