A much-anticipated report by the National Academy of Sciences concluded the science used by the U.S. Fish and Wildlife Service to manage threatened and endangered animals in the Platte River Basin is sound, but cautioned about gaps in some areas of research.

The 208-page report, begun in January 2003 and published Wednesday, said the U.S. Fish and Wildlife Service used correct science in crafting its plan to manage the Platte River Basin in its draft environmental impact statement. That statement is currently undergoing public review.

The group of 14 scientists said the Service had correct knowledge to determine that the piping plover and interior least tern are imperiled, and proposed protections will help their recovery. But, the report said more information is needed to determine whether proposed habitat protections will help the endangered whooping crane and pallid sturgeon.

"Valid science supports critical habitat designations for the piping plover, but the scientific support of critical habitat designation for the whooping crane is weak," the report said.

Still, William Graf, chairman of the National Academy of Sciences (NAS) said the 14-person group is "confident in decisions and recommendations" set forth by the Fish and Wildlife Service.

"Implementing the plan is something that frankly we don't have an opinion on," Graf said. "The purpose of the NAS is to assess the science and determinations made. Hopefully we give people … some confidence."

Graf said the Service should feel confidence with regard to its proposed management plans.

Ralph Morgenweck, director of the Service's Mountain-Prairie region, said his agency was "pretty pleased" with the report.

"What it does is look at the science we used and gave us a pretty good 'thumbs up,'" he said. "The Academy has buttressed the decisions the Fish and Wildlife Service has made relative to its critical habitat findings. I didn't see anything that said we missed the mark at all."

Morgenweck said the "gaps" the NAS noted - that some data was outdated and that some habitat considerations were not well studied - would not preclude the agency from moving forward with its management plan.

"We always would like more information," Morgenweck said. He said the agency would be working with three states - Colorado, Nebraska and Wyoming - to close the information gaps.

The DEIS is undergoing public review, and that public review period will likely be extended for a few weeks from its June 2 deadline, said Maryanne Bach, Great Plains regional director for the U.S. Bureau of Reclamation. This will allow the public to review the NAS document, she said.

This is the second time the public comment date has been pushed back. It moved from April 2 to June 2 in March.

Alternatives currently outlined in that document will not change until after public review, she said.

Bach also said the plan to increase water levels in the Pathfinder Dam is still viable.

The NAS report said, in part, that current central Platte habitat conditions "adversely affect the likelihood of survival of the whooping crane, but to an unknown degree."

About 7 percent of the nation's whooping crane population stops on the central Platte River. Up to 80 percent of crane mortality occurs during migration, and because the Platte River is central to the bird's migration, the environment is key, the report said, and the FWS designation of the area as critical habitat was supported.

Graf, with the NAS, said the whooping crane population is "vanishingly small," about 194 birds. He said the crane and the pallid sturgeon are so imperiled that "it's not really something we are going to be able to fix anytime soon."

The NAS committee also upheld the FWS conclusions that the threatened piping plover is impacted by Platte River habitat conditions, and a degradation of conditions would affect the likelihood of its survival. The same finding was found for the endangered interior least tern.

Regarding the pallid sturgeon, the scientists said current habitat conditions "do not adversely affect the likelihood of survival and recover … because that reach of the river appears to retain several habitat characteristics apparently preferred by the species."

The report also said the pallid sturgeon population is so low that the lower Platte River is "pivotal in the management and recovery of the species."

The NAS report also said human-caused mortality is among the main threats to the four species. Habitat loss - often associated with human activities - is another main threat.

Copies of the DEIS can be found on the Platte River EIS Office Web site,(http://www.platteriver.org).