Officials take aim at Flathead macks

A proposed fishing regulation for Flathead Lake would more than double the daily limit on lake trout, which were introduced to the lake about 100 years ago and prey on native fish.

The new daily limit of 50 lake trout, up from 20, has tentative approval of state fish and wildlife commissioners and is up for public comment through Sept. 15.

Fisheries managers proposed the increase and see it as a step in managing the lake trout population, but not a big step.

The increase is unlikely to cause a major rise in the number of lake trout removed from Flathead Lake, given that few anglers now harvest the 20 allowed, said Jim Vashro, the Montana Department of Fish, Wildlife and Parks’ fisheries manager in Kalispell. Anglers release many of the lake trout they catch, except during fishing contests, Vashro said. It is during those contests, which offer prizes, that managers expect to see increased catches.

Lake trout that anglers do remove from Flathead Lake number 40,000 to 50,000 a year, Vashro said. The lake has about 250,000 of catchable size, he said.

Flathead Lake fish are managed under an agreement, adopted in 2000, between the Montana Department of Fish, Wildlife and Parks and the Confederated Salish and Kootenai Tribes.

“We’re trying to bring the fishery back into balance,” Vashro said.

Encouraging bull trout, which are on the federal threatened-species list, and native westslope cutthroat trout in Flathead Lake is among the goals of a management plan.

Flathead Lake’s bull trout population is estimated at 4,000 or 5,000 fish. Vashro said the number of cutthroat is difficult to gauge. Work attempting to track the species is planned for the spring, he said.

Lake trout were introduced to Flathead Lake in 1905, apparently to diversify fishing opportunities, Vashro said.

The fish is a concern elsewhere in Montana, but less so than at Flathead Lake. Its lake trout population boomed, and native fish declined steeply, after freshwater shrimp introduced in other Montana waters ended up in Flathead Lake, as well. The shrimp became food for lake trout and compete for zooplankton that native fish consume.

Lake trout are native to several Montana lakes and were introduced in about a dozen others.