GLACIER NATIONAL PARK - Glacier National Park is proposing to build a special barrier to keep non-native fish from invading the Quartz Creek drainage, considered the last park drainage still free of non-native fish.
Jerry O'Neal, the park's deputy superintendent, said fisheries biologists believe such a barrier is necessary to protect the important population of bull trout and westslope cutthroat trout.
The $20,000 barrier would be paid for in part by the Glacier Fund, a nonprofit group raising money for park projects that might otherwise fall through the cracks.
The park is taking public comment on its proposal through June 9.
Fisheries biologists say blocking non-native fish is especially important in a place such as Quartz Lake, which is among the last lakes in the Columbia River Basin that still have a full complement of native fish and remain untainted by non-natives.
Quartz Lake is actually three lakes connected by Quartz Creek on the parkÃ s northwestern side. They drain into the North Fork of the Flathead River.
The two uppermost lakes in the chain are known to be free of non-native lake trout. Fisheries biologists are recommending a special barrier that would be placed between the lower and middle lakes, preventing any lake trout from swimming upstream.
Since Glacier National Park was designated in 1910, native fish populations have been dwindling in many park drainages, often the result of an early policy that favored direct stocking of non-native fish.
"As a result," O'Neal said, "native fish began breeding with non-native fish - native westslope cutthroat trout bred with non-native Yellowstone cutthroat or rainbow trout. In more recent decades, the major impact on native fish has been from the invasion of non-native species through the Flathead River system into the lakes and streams of Glacier."
The non-native species compete with native fish both for food and in breeding.