The National Park Service’s intermountain regional director has signed off on a plan to build a fish passage barrier downstream of Akokala Lake in Glacier National Park’s North Fork region.

The barrier is intended to protect native fish populations, including bull trout and genetically pure westslope cutthroat trout, from impacts by non-native invasive fish species, including lake trout, rainbow trout and possibly brook trout, according to Park officials.

Akokala Lake is one of the last bull trout supporting lakes on the Park’s west side that is at risk of invasion but not yet colonized by non-native lake trout, Park officials said. The barrier will not impede downstream movements of native fish.

Construction will take place in late summer and fall when water flows are low. Park spokeswoman Denise Germann said construction will take place in 2015 and cost about $90,000.

An environmental assessment for the fish barrier project was released for public review in June 2014. Twelve comment letters were received, with nine in support and one expressing concerns about impacts to wilderness. The environmental analysis and decision document can be found online at http://parkplanning.nps.gov/AkokalaFishBarrier.

The project comes on top of a recently approved plan to continue lake trout suppression on Quartz Lake and begin lake trout removal and bull trout conservation in the Logging Lake drainage. The project is estimated to cost about $700,000 for the first three years, Park fisheries biologist Chris Downs said.