Imperiled Rio Grande Minnows Die

A section of the Rio Grande went dry this week, killing about two dozen endangered silvery minnows and prompting biologists to try to rescue about 100 more of the tiny fish.

Federal water managers and wildlife officials said that hot weather was largely responsible for drying seven miles of the river through the Bosque del Apache National Wildlife Refuge south of Socorro.

Biologists from the U.S. Fish and Wildlife Service and other agencies rescued minnows trapped in small, isolated pools of water along the river Monday and Tuesday.

About 100 minnows were collected, but 15 of those died while being moved, said Joy Nicholopoulos, field supervisor for the service in New Mexico.

“We’re trying to determine what impacts [the drying] had ... but it seems pretty minimal at this point,” she said.

As temperatures increased late last week, more water was needed to keep the river flowing, said Jim Wilber, a biologist at the U.S. Bureau of Reclamation.

Water managers began releasing extra water from upstream reservoirs and adjusting irrigation releases, and the flow was resuming, Wilber added.

Attorney Letty Belin of the Land and Water Fund of the Rockies said it appears the federal government violated an Endangered Species Act requirement for minimum flows in the river through June.

Starting May 30, the flow in the Rio Grande at San Marcial fell below 50 cubic feet per second, which is the benchmark in the plan, according to the U.S. Geological Survey.

“We’ll be watching to see what the agencies do about this,” said Belin, who represents several environmental groups that sued the federal agencies over protections for the minnow.