Feds to release endangered minnows in Big Bend

Thousands of endangered Rio Grande silvery minnows reared at a national hatchery in New Mexico were being prepared Wednesday to be trucked to Texas, where the tiny fish will be released into the Rio Grande near Big Bend National Park.

The release is part of a five-year experiment by the U.S. Fish and Wildlife Service to establish a population of minnows in the river's southern reaches. More than 400,000 silvery minnows were released at Big Bend last year and surveys have shown that there are still minnows in the area.

"It's a little early to really say that this is a successful program, but we're definitely learning and we're hopeful," Fish and Wildlife Service biologist Aimee Roberson said.

Hatchery staff members on Wednesday were loading 500,000 minnows into several trucks for the overnight drive from southeastern New Mexico to Big Bend. About 60,000 minnows bound for Texas came from the city of Albuquerque's breeding facility.

Manuel Ulibarri, director of the Dexter National Fish Hatchery and Fish Technology Center, said it's a big effort involving many agencies.

The silvery minnow once was abundant in the Rio Grande from New Mexico to the Gulf of Mexico. Due to environmental pressures on the river and changes in habitat, the minnow now occupies only a stretch in central New Mexico, just 5 percent of its historic range.

The minnow's fate is shared by dozens of other aquatic species in the West. The Fish and Wildlife Service says for many of these species, populations are small and concentrated in fragmented portions of rivers that are vulnerable to drying and low flows.

The agency says hatcheries like the one at Dexter have become increasingly important as both short-term refuges and long-term breeding facilities.

More than 30 species of listed fish, wildlife and plants are in the care of hatcheries in the Southwest, including 15 fish species at the New Mexico facility.