More than 15 years in the making, the final recovery plan for bull trout was released Monday by the U.S. Fish and Wildlife Service, although some environmentalists and biologists in Montana say it still falls short of providing an avenue to recover the threatened species.

Listed under the Endangered Species Act in 1999, bull trout populations in the continental U.S. have struggled throughout the past century, under pressure from invasive species, habitat degradation and warmer waters.

The warming effects from climate change are also expected to create further problems for the fish, which require clean, cold water to survive. Steve Duke, a senior biologist with the U.S. Fish and Wildlife Service, said some current bull trout habitats will no longer be habitable if water temperatures continue to rise as projected. That’s one reason the plan language that allows up to 25 percent of the individual populations to disappear within four of the six geographically defined recovery units.

“Despite some loss, we still feel that bull trout in each of these recovery units would persist at a level where they would be viable, even with the loss of some of these populations,” Duke said Monday. “There’s likely to be some recovery units that, as far out as we can project, recovery won’t be achieved or can’t be achieved.”

The six recovery units span bull trout habitat in Montana, Idaho, Washington and Oregon, along with an isolated population in northern Nevada. Northwest Montana’s bull trout are included in the Columbia Headwaters recovery unit, which extends through the Idaho Panhandle into eastern Washington.

It’s also one of the recovery units for which the 75 percent threshold for recovery applies. Duke said one of the only differences between the draft and final plans made that threshold more stringent in the Columbia headwaters, since 15 of the unit’s 35 “core areas” house multiple populations of bull trout. Now that standard must be met in the single-population areas in addition to the complex ones, rather than overall.

Before, “you could conceivable fix all of the complex core areas and allow just the single core areas to be extirpated,” Duke said.

Michael Garrity, executive director of the Alliance for the Wild Rockies, is still sharply critical of that threshold, calling it an “extinction plan.”

“One of the criteria for bull trout is that they need cold water, but their answer to that is, ‘Oh well, there’s nothing we can do, and we’ll just count them as recovered even though they’ll continue to die because of rising temperatures,” Garrity said. “You could have stricter criteria for protecting riparian areas to ensure the creeks are shaded by trees to keep the temperatures from going up, for example.”

Garrity also blasted the plan for failing to include demographic requirements to establish a population as “recovered.” And while Montana Fish, Wildlife and Parks has sided with the agency on accepting that up to 25 percent of the trout populations will face extirpation, state officials have also objected to the “threats-based” approach outlined in the plan, which foregoes target population numbers.

“We continue to propose and advocate that demographic information can and should be used to develop reasonable recovery objectives for bull trout in Montana,” the state agency wrote in its comments on the plan. “Such criteria would not require a vague ‘threats managed’ process, and would result in a recovery plan ... more tangible, feasible and acceptable to resources managers and the public.”

Duke said the federal agency chose instead to focus on a “demographically stable” requirement that identifies threats to bull trout. He said that allows regional and state management agencies to better tailor their approach to the most pressing threats for specific populations.

Measures of success, he added, can be defined by those agencies depending on what works best for them — including redd counts, which Montana Fish, Wildlife and Parks has used for decades to track bull trout populations in the state.

In all likelihood, the fight over the recovery plan is still not over. Garrity expects to sue the agency over the plan, although he declined to elaborate on the legal arguments his organization or others would likely pursue.

“We will most likely sue on this, because it’s not following the legal requirements of the Endangered Species Act,” he said. “It’s primarily due to habitat degradation. Migratory corridors are blocked by roads, culverts or dams and because of stream-side logging we have rising water temperatures and sediments. ... Instead of dealing with those hard things, they’re just blaming it on climate change and invasive species.”