KALISPELL - Eight years ago, state and tribal fisheries biologists mapped out a plan to manage the explosion of non-native trout in Flathead Lake.

It was a compromise of competing goals - seeking to reduce lake trout numbers (thereby saving endangered native fish) while at the same time providing a lake trout fishery for sport anglers.

Now, as the plan enters its final year, many are calling for a more aggressive approach to killing lake trout, with the state becoming increasingly isolated in its "go-slow" position.

Mark Deleray, fisheries biologist with the Montana Department of Fish, Wildlife and Parks, says native bull trout populations are "stable, and stable is good." He thinks things are progressing fairly well, and notes the plan's goals are being met.

But Wade Fredenberg, who is charged with recovering threatened bull trout under the Endangered Species Act, argues that "stable isn't progress."

He calls Flathead Lake "the evolutionary heart of bull trout in the region" and "the bull trout's best hope," and says "the expectation eight years ago, when they signed that plan, was that we would make progress. Since then, it's been like Groundhog Day - fundamentally, nothing's changed for Flathead Lake in eight years."

Much, however, has changed in upstream waters now invaded by lake trout that swam up from Flathead Lake.

"Clearly," Fredenberg said, "when you look at the whole system, things are measurably worse."

And so the fish scales appear to be tipping, as stakeholders far beyond the lake scramble to control the non-native invasion. Calls are increasing to ratchet up the assault on lake trout, even as the current eight-year plan expires. But state officials are reluctant to act as quickly as others would like.

"To say there's tension would be a huge understatement," said Fredenberg of the U.S. Fish and Wildlife Service.

Tom McDonald calls the growing management divide a "gulf." Jim Satterfield calls it a "chasm."

How it is bridged will have implications for native fish - and fishermen - throughout the region.

McDonald manages the Fish, Wildlife, Recreation and Conservation division for the Confederated Salish and Kootenai Tribes, which control the lower half of Flathead Lake.

Satterfield is supervisor of Region 1 for the state FWP, which controls the upper half of the lake.

Together, they are the co-managers of the fishery under the eight-year plan.

The seeds for that plan were planted a century ago, when the first lake trout were planted in Flathead Lake. For decades, the fish swam at relatively low numbers, co-existing fairly well with native bull trout and westslope cutthroat trout.

But when mysis shrimp were introduced - as food for yet another non-native - the historic food web unraveled. Suddenly, lake trout had a nearly unlimited food source, and numbers exploded.

Lake trout are big, and hungry, and they ate their way through the stock of native bulls and cuts. In 1998, bull trout were listed as "threatened" under the Endangered Species Act.

Since then, Fredenberg said, much has been done to bolster native populations, but most of the effort has focused on habitat restoration along distant spawning streams.

Now, with that habitat largely recovered, it's time to turn to the source, he said.

"It's the lake trout, stupid," he said.

Wade Fredenberg thinks of bull trout populations the way he thinks of the Christmas lights tangled in his basement. The populations are all strung out, individual colors linked by streams with a big star - a lake - at the top.

Some of the lights - Coal Creek, Red Meadow Creek, Kintla Lake, Bowman Lake - have started fading, he said, and might soon blink out

And if they do, worries biologist Clint Muhlfeld, the whole string could go dark. Muhlfeld works for the U.S. Geological Survey, and says that as individual populations blink out, the already tenuous species loses crucial genetic diversity and local adaptations. "And that absolutely increases the likelihood of extinction in the larger meta-population."

For Fredenberg, it's a no-brainer - hit the lake trout harder.

"Otherwise," said Glacier National Park biologist Chris Downs, "the outlook for these fish is certainly not good."

In just 25 years, Downs said, lake trout have pretty much replaced bull trout in the park's western waterways, "and that's directly related to the invasion of lake trout from downstream. The status quo in Flathead Lake definitely isn't helping us any."

Muhlfed said that of the 12 Glacier Park lakes connected to Flathead Lake, 10 are now infested with lake trout, and "nine of those 10 are on the brink of extinction, no doubt. There's just no doubt. Managing for lake trout in this system is absolutely inappropriate."

Eliminating lake trout is impossible, but hitting Flathead Lake harder, Downs said, "obviously makes sense to me."

It also makes sense to McDonald, whose tribal offices also have begun pushing recently for a more aggressive approach. "We need to step it up," he said.

But neither Fredenberg nor Downs nor Muhlfeld nor McDonald has to deal with an angling public that likes to catch lake trout. The state does, though.

And therein lies the rub - the "chasm" as Satterfield calls it, between "value systems." At FWP, he said, he's not just dealing with biology, but also with sociology and economics and a sometimes untrusting public.

Some say a viable lake trout fishery would remain even if fish numbers were cut dramatically, but Satterfield's constituents are not so sure.

"I want to move carefully," he said, "with whatever we do. Things are evolving right now, and we need to be careful."

Already, the state has moved aggressively to kill lake trout in other waters. And FWP has increased the lake trout "bag limit" on Flathead Lake from five fish to 50. They've promoted fishing derbies that, combined with traditional angling, are taking some 50,000 lake trout per year out of Flathead Lake.

"We're very committed," Satterfield said.

But with a population of 400,000 lake trout, it's just not enough.

Other states have enacted bounties on lake trout, but Satterfield said "I'm not ready to go there yet."

"Right now," he added, "we don't have a next step."

The future of management, Muhlfeld said, "seems to be at a standstill."

As to the state's "slot limit," which protects big, trophy lake trout, "it might be time to give that up," the tribe's McDonald suggested.

Some sort of netting program is possible, Satterfield said, but would have to first be vetted through a public environmental assessment.

In fact, he said, FWP proposed an assessment for a netting project just last spring.

The tribes, meanwhile, could begin a netting program on the southern lake without state involvement, Fredenberg said, "but no one wants to see the two ends of the lake managed independently."

"What makes sense to me," Downs said, "is a comprehensive basinwide plan, a coordinated strategy throughout the region, that doesn't look at the lake in isolation from all these other places."

Fredenberg agrees, and thinks that strategy should rearrange the risks and rewards currently emphasized. The lake trout should carry the burden of risk, he said, and the bull trout should enjoy the rewards, rather than the other way round.

Satterfield wants assurances that any plan to help bull trout will actually work; others say there are no guarantees, and no time, either.

Because "these lights are blinking out," Fredenberg said, "and we don't have forever to sit around and talk. We need to get moving."

Especially up in Glacier, where Downs is watching a steep decline of natives.

"These bull trout," he said, "are at really low levels, and our time horizon is very short. Some people say it's too late already, but you have to try."

Which is exactly what Satterfield says the state's been doing.

"This is a complex issue," he said, "and we're going to have to continue working together to sort it all out."

Reporter Michael Jamison can be reached at 1-800-366-7186 or at mjamison@missoulian.com.