Glacier plan would protect native fish

WEST GLACIER, Mont. – Glacier National Park officials have come up with a new plan to help turn away invaders from Canada that threaten what is considered the park’s last drainage free of non-native fish.

The proposal calls for building a special barrier that would prevent non-native lake trout from entering Quartz Creek, home to native bull trout and westslope cutthroat trout.

Fishery surveys in and around the park have shown non-native fish have crowded out native species, and interbreeding eventually pollutes the native gene pool.

That is of special concern near Quartz Creek, where work in adjacent drainages has revealed a near complete replacement of bull trout by invasive lake trout in the past three decades. Scientists have long advocated a barrier between Lower and Middle Quartz lakes to stem the spread of lake trout.

In May 2003, park officials proposed just such a barrier, but a month later the plan was scrapped when heavy spring runoff raised concerns the proposed barrier would not handle high-water flows.

The original plan – to create a 4- or 5-foot waterfall from bundles of rock – was abandoned after a site visit showed the stream washing over its banks with spring runoff.

Scientists decided the fish would simply swim around the barrier at high water, and the barrier itself would likely be blown away by the pulse of water in the main channel.