Glacier National Park has finalized a plan to expand its war on lake trout in two North Fork lakes.

The National Park Service last week released a finding of no significant impact for its plan to continue gillnetting and killing lake trout in Quartz Lake and to expand that same effort to nearby Logging Lake.

All told, the effort at both lakes is expected to cost about $700,000 for the first three years of the project, Park fisheries biologist Chris Downs said.

Lake trout are a non-native species west of the Continental Divide and have decimated native bull trout populations in lakes where the two exist. Bull trout are listed as threatened under the Endangered Species Act.

The plan calls for a three-pronged approach. For one, gillnetting of lake trout in Quartz Lake will continue for the next six to eight years. That effort started in 2009 and has shown signs of suppressing lake trout populations while helping preserve the native bull trout population, the plan’s environmental assessment states.

Secondly, netting of lake trout in Logging Lake will begin next year. Biologists will first capture and radio tag lake trout and then track them to spawning areas.

After they’re netted and killed, the lake trout’s air bladders will be cut so they sink to the bottom of the lake and do not become attractants for bears.

Motor boats will be used on both Quartz and Logging lakes. The Logging Lake boat will be less than 25 feet long and the motor will have less than 90 horsepower — possibly twin outboards for safety reasons.

Thirdly, the Park Service plans to capture juvenile bull trout from the Logging Lake drainage and transport them upstream to Grace Lake.

Grace Lake currently does not have a bull trout population, but it does have a natural waterfall barrier between it and Logging Lake. Grace is seen as a possible refuge for long-term bull trout survival in the drainage.

Biologists also plan to gather fertilized eggs from spawning bull trout in the Logging drainage and rear them at the Creston Fish Hatchery for future stocking in Grace Lake. The Park Service anticipates that lake trout netting could be reduced once the population is suppressed.

Most public comments opposed to the project centered on wilderness values and the long-term use of motor boats in both drainages. There were also concerns about nesting loons and bald eagles. Both lakes offer excellent loon and eagle habitat.

Netting does not eliminate lake trout, it only suppresses them, the Park concedes. While the region is not designated wilderness, it is recommended wilderness and the Park manages it as such. In this case, the Park says, preservation of the fishery overrides wilderness impacts from motorized use.

Biologists will also look at other experimental methods, such as spearfishing spawning lake trout and using electrocution to kill lake trout eggs on their spawning beds.