State officials fear the reintroduced otters will feed on endangered native fish in the upper Gila. "You can't tell an otter what to eat," says biologist Jim Stuart. This river otter is swimming in northern New Mexico.

NEW MEXICO GAME AND FISH DEPARTMENT

ALBUQUERQUE - The last time anyone had documented a river otter in New Mexico was nearly 60 years ago on the Gila River. A government trapper found the dead animal in a beaver trap.

Now the chance of otters making a comeback in the upper reaches of the Gila is being put on hold indefinitely by New Mexico wildlife officials, a move that is frustrating conservationists and others who see the sleek mammals as the best hope for preserving endangered fish in the river.

The Gila is an example of what has happened to rivers throughout the West. From choking drought conditions and habitat changes to an influx of exotic species, a number of factors have helped push populations of native fish to dangerously low levels.

It's those endangered fish that the New Mexico Game and Fish Department says it's worried about. The department contends Arizona wildlife officials and the U.S. Fish and Wildlife Service have expressed similar concerns.

Playful and highly social, otters love to eat fish. Supporters of the reintroduction program argue the otters' first choice will be invasive crayfish and larger, slower nonnative fish like bass and carp.

"We're aware of the arguments - and I agree with a lot of the arguments - that having a species that preys on fish might actually be beneficial to some extent because of the large number of nonnative fish in the Gila," said Jim Stuart, a biologist with the department's Conservation Services Division. "But you can't tell an otter what to eat, and we do have some populations of listed fish down there that are in pretty bad shape right now. They're right on the edge."

The decision to pull the plug on otter reintroduction was spelled out in a three-paragraph letter sent recently by Stuart to members of the New Mexico River Otter Working Group.

Supporters of the program balked at the state's reasoning, pointing to Utah, Colorado, Arizona and other states that have had success in reintroducing otters, even in rivers that are home to endangered species.

They also say the letter marked the first time that Arizona's concerns had been documented by New Mexico officials. The working group has had no discussions with Arizona wildlife officials.

Melissa Savage, director of the Four Corners Institute and a member of New Mexico Friends of River Otters, said New Mexico's action flies in the face of a 2006 Game Commission decision to move forward with reintroductions on the Upper Rio Grande near Taos and the Gila River. The decision was based on a feasibility study that looked at several river systems in the state.

More than 30 otters were released into the upper reaches of the Rio Grande between 2008 and 2010 and seem to be holding their own. Releases on the Gila were initially planned for 2010 but the program stalled despite a biological opinion on the potential impacts and an intensive monitoring plan.

The working group, which has been funding the otter program, has already spent about $20,000 of private funds and donations on the Gila effort.

"These fish populations are declining, so what is the plan? Are we going to sit here and watch them go down or are we going to try this?" she said. "We can take the otters out if it doesn't work."

Donna Stevens of the Upper Gila Watershed Alliance said otter reintroduction is "the only inexpensive and practical way" to save the Gila's native fish.

Decades of trapping and habitat loss are believed to be factors that led to the otters' disappearance.

More than 20 states have successfully reintroduced river otters, which biologists say play an important role in keeping semi-aquatic ecosystems healthy and diverse.