JACKSON - The Yellowstone cutthroat trout is again being considered for the endangered species list, following action by a federal judge in Colorado.

U.S. District Judge Philip Figa ruled Friday that a petition to list the trout was illegally rejected by the U.S. Fish and Wildlife Service, saying instead there was "substantial scientific and commercial information indicating that listing of the (Yellowstone cutthroat trout) as a threatened species may be warranted."

The Yellowstone cutthroat trout - found primarily in northwest Wyoming - is one subspecies of cutthroat. It was petitioned for federal protection in 1998 and rejected for listing in 2001.

The Snake River cutthroat is grouped with the Yellowstone, though its spots are smaller.

Federal protection of the trout could result in restrictions on activity around the waters where the fish is found, both on government-owned and private land. Livestock grazing, timbering and other industries could be affected, and restrictions on fishing could be imposed as well.

Several conservation groups, including the Laramie-based Biodiversity Conservation Alliance, filed suit against the 2001 decision not to list the Yellowstone cutthroat, saying the trout's habitat has greatly diminished and it is increasingly threatened by habitat loss and by competition with nonnative trout.

Jeremy Nichols with Biodiversity Conservation Alliance said he is "hopeful" after Figa's decision to reconsider listing the fish.

"Their loss, we feel, is irreplaceable," Nichols said. "Keeping the Yellowstone cutthroat here and recovering the population should be a priority for fish and wildlife managers."

In his decision, Figa said the Fish and Wildlife Service applied an "incorrect standard" in its evaluation of the petition to list the trout. In a 90-day finding, the agency is supposed to simply determine if there is enough information to warrant further review.

Instead, Figa said, the agency evaluated whether the Yellowstone cutthroat "faced a high probability of extinction."

The Fish and Wildlife Service also solicited information from state agencies but not from the general public, Figa said, and agencies detailed future conservation measures.

"The law is clear that FWS cannot consider future conservation efforts in its review of the Petition," Figa wrote in his decision.

Steve Yekel, regional fishery supervisor for the Cody region of the Wyoming Game and Fish Department, said he hopes the Yellowstone cutthroat will not be listed because it would limit the work he and other cooperating agencies can do.

Yekel said a conservation strategy is being developed throughout the region - a strategy identified by the Fish and Wildlife Service as one reason not to list the trout - and will be furthered this year.

Streams are repopulated with Yellowstone cutthroat, and Game and Fish is working with private landowners and the U.S. Forest Service to help the trout's habitat.

Yekel said since he arrived with Game and Fish in 1977, the agency has worked on Yellowstone cutthroat issues. The trout is estimated to be in 43 percent of its historic range, he said.

Conservation groups have said the trout is in just 10 percent of its historic range.

Hybridization with rainbow trout has harmed the Yellowstone cutthroat, and the introduction of nonnative trout causes competition for food sources. Lake trout in Yellowstone Lake are squeezing out the cutthroat, too, prompting the National Park Service to call for the killing of any lake trout caught there.

Whirling disease has also been found in many streams home to the Yellowstone cutthroat, further jeopardizing its survival.

Figa said the Fish and Wildlife Service did not properly consider whether the trout's habitat was threatened by fragmentation or degradation.

The agency said much of the information in the petition to list the trout was outdated, but Figa said, "the information was not necessarily inadequate or incorrect."

Groups petitioned for Fish and Wildlife Service review in 1998, then filed suit after the agency had not acted on the petition in a timely manner.

The groups filing suit include the Center for Biological Diversity, Biodiversity Conservation Alliance, Pacific Rivers Council and Ecology Center, and they were represented by Earthjustice.

Environmental reporter Whitney Royster can be reached at (307) 734-0260 or at royster@trib.com.