Federal and private biologists airlifted hundreds of imperiled fish into southeast Arizona waters Thursday to give the fish a chance to make it in the wild.
The fish - the endangered desert pupfish and the threatened spikedace and loach minnow - were released into two springs and two canyons in the Muleshoe Ranch Cooperative Area on the southwestern edge of the Galiuro Mountains, about 30 miles northwest of Willcox. The release was a cooperative effort by the Nature Conservancy, the state Game and Fish Department and three federal agencies.
This is the fourth year of what is planned to be at least a five-year effort to introduce the fish into these remote waters that authorities say are far less impacted than many other Arizona water bodies by such things as groundwater pumping, cattle grazing, off-road vehicles and the introduction of non-native species.
The Muleshoe cooperative area covers about 57,000 acres. It is jointly managed by the conservancy and the U.S. Bureau of Land Management.
The fish were flown in by helicopter in barrels or coolers from sites where they had been kept in captivity. Then they were transferred into 5-gallon buckets and carried to the release areas.
At the stocking sites, field crews working on the project added small amounts of spring and stream water to gradually bring the water temperatures and quality within the buckets in line with those in the canyons and springs. Then the fish were gently poured into the natural waters.
About 500 desert pupfish were brought in from a preserve pond owned by the conservancy at the San Pedro River near Dudleyville. The 1,920 spikedace and 620 loach minnows came from a state-run fish hatchery in central Arizona.
"We're pretty optimistic about this project. Over the last two years we've seen these species persisting," said Jeff Sorensen, Game and Fish's native fish and invertebrate program manager. "It just requires commitment and additional stocking to get them established to the point where they are self-sustaining populations."
All three fish are in trouble primarily because of habitat loss by the invasion of non-native fish, biologists have said over the years. Their current ranges are a fraction of the size of those a century ago because of water pumping, diversion, stream channelization, damming of streams and overgrazing, federal scientists have said.
A fourth fish, the endangered Gila topminnow, had been stocked in canyons and streams at Muleshoe for three years through 2009. Since surveys showed they appeared to have established self-sustaining populations by 2009, none were released there this year, Sorensen said. The other fish have persisted from earlier releases, but not in as large a number, Sorensen said.
The topminnow, which can produce lots of young several times a year, are a lot more adaptable than the minnows and pupfish to new opportunities, Sorensen said. But as long as the fish have habitat, reduced threats and available resources, the other species should ultimately fare well, Sorensen said.
Previously, the release sites of Hot Springs Canyon and Redfield Canyon at Muleshoe were supporting populations of the endangered Gila chub along with the native Sonora sucker, speckled dace and longfin dace. Hot Springs Canyon also has the native desert sucker. Headquarters Spring and Secret Spring at Muleshoe, both isolated springs, are ideal for establishing the topminnow and the pupfish, Sorensen said.
The releases came a day after the U.S. Fish and Wildlife Service announced a fourth proposal over nearly 20 years to designate streams and rivers in Central and Eastern Arizona and western New Mexico as prime habitat for the spikedace and loach minnow. In critical habitat, the service must review all federal projects and federally permitted projects scheduled for these locations. The Endangered Species Act forbids any activity causing serious harm - the formal term is "adverse modification" to critical habitat.
Previous versions of critical habitat for the fish were thrown out by courts or voluntarily withdrawn by the Fish and Wildlife Service after challenges to the designations came in from industry groups that contended the habitat protection would harm rural economies, or environmental groups that called the proposals inadequate. The latest proposal is for 796 miles.
Contact reporter Tony Davis at firstname.lastname@example.org or 806-7746.