Groups further effort to protect cutthroat

Claim hybridization, loss of habitat pose threats.

An eight-year-old legal fracas over Yellowstone cutthroat continues after conservation groups announced they would once again sue the U.S. Fish and Wildlife Service to force protection of the trout.

The Pacific Rivers Council and the Center for Biological Diversity filed a 60-day notice of intent to sue the service, saying that the government agency is illegally denying Endangered Species Act protection to the Yellowstone cutthroat.

The vast majority of Yellowstone cutthroat populations have at least one, if not several, threats to their survival, the groups said. These threats include habitat loss, whirling disease and hybridization with other species, especially rainbow trout.

"A number of those threats are really acute at the moment, and we dont have a good way of getting control over them," said Chris Frissell, senior staff scientist at the Pacific Rivers Council.

"In this case, everyone agrees that the Yellowstone cutthroat trout is gone from 90 percent or more of its range, and continues to be threatened in the majority of its remaining range," said Noah Greenwald, a conservation biologist with the Center for Biological Diversity.

Government experts disagree

In contrast, government experts say the Yellowstone cutthroat have stable habitats and the fish remain plentiful.

"We did not see support for the premise that things are going to hell in a hand basket, and that Yellowstone trout are about to disappear from the map," said Wade Fredenberg, native species coordinator for the U.S. Fish and Wildlife Service. "There's a core area that is relatively stable, solid habitat that supports robust populations."

Hybridization "is not unique to Yellowstone cutthroat, it's an issue that were wrestling with in cutthroat across the range," Fredenberg continued. "Our conclusion was that, again, there is a relatively large component of Yellowstone cutthroat that are currently not threatened by hybridization."

But counting hybrid fish is tricky, Frissell said. To start, even fish that look like native cutthroat still may have one invasive species parent. Fish and Wildlife officials consider a cutthroat trout population pure if 5 percent or fewer of the sampled fish look like non-native fish. But, according to Frissell, once 2 percent of the fish in a population become hybrids, it only takes about 20 years before interbreeding causes hybrids in 100 percent of the population. "It doesn't go back from hybrid to pure," he said. "You cant ever recover that native species out of that mix again."

Instead of 5 percent, Frissell says a population can only be considered genetically pure when less than 1 percent of the fish show signs of hybridization. Counted that way, only a handful of fish populations remain pure Yellowstone cutthroats.

State officials side with feds

State officials, who also have a stake in the lawsuit, agree with the Fish and Wildlife Service that the Yellowstone cutthroats are safe. State biologists have worked for the last 30 years, spending a significant amount of time and resources to better understand cutthroat trout distribution, genetics, life history and habitat, said Dirk Miller, fisheries management coordinator for Wyoming Game and Fish.

"We feel like that was an appropriate decision not to list," Miller said. "They exist in sufficient numbers and are reasonably protected so that listing isnt warranted."

The Biodiversity Legal Foundation (now the Center for Biological Diversity) first filed a petition to list the Yellowstone cutthroat trout as an endangered species in August 1998. In 2000, the group sued the U.S. Fish and Wildlife Service for failure to respond to the petition. In February 2001, the service issued a negative finding, saying the fish did not need protection.

In January 2004, the conservation groups sued again, saying the 2001 finding did not rely on the best available science. The conservation groups won that battle, and Greenwald says they could win this latest round.

"I think their current decision suffers from the same flaws," he said.

If the conservation groups do win, that doesn't mean anglers can't fish for Yellowstone cutthroat trout. Frissell says its more important to protect habitat than individual fish.

"It's actually great news that there are still a fair number of fish in a dozen or so populations," he said. "That means there's still potential to stop the decline and turn the species around. Ten years from now, we may not have that opportunity."