Gill netting: Flathead Lake could be next test case for controversial program

Although Montana Fish, Wildlife and Parks has been using gill netting on Swan Lake for five years, that doesn’t necessarily mean that it should be used on Flathead Lake.

That’s the word from the state agency’s fisheries biologist Mark Deleray.

After a two-year study by a MSU student, Fish, Wildlife and Parks began a gill netting experiment on  Swan Lake in 2009. The program received a five-year extension after the first three years were complete.

The program is an experiment to see if the removal of non-native lake trout leads to an increase in the population of native species such as bull trout and kokanee salmon.

Leo Rosenthal is the state’s fisheries biologist on Swan Lake. He notes that the agency is seeing evidence that gill netting is having an effect on lake trout, but hasn’t yet seen an increase in bull trout. “We hope to start seeing growth within three more years,” he said.

Bull trout spend three or four years in the lake before they spawn, he said.

The agency will start its annual redd, or nest, count of spawning beds in the 12 tributaries that feed into Swan Lake within the next two weeks.

Montana Fish, Wildlife and Parks and the Confederated Salish and Kootenai Tribes co-managed Flathead Lake through a 10-year plan that began in 2000. Since it expired, the tribes have proceeded ahead on a new environmental plan.

On Sept. 19, the CSKT Tribal Council recommended the most aggressive gill netting option for Flathead Lake in an effort to decrease lake trout and increase bull trout. The tribes are currently incorporating public comment from a draft environmental impact statement into a final environmental impact statement. There will be a 30-day comment period afterward, with those comments to be incorporated into the final plan. The tribes hope to have the final EIS available this fall, according to CSKT fisheries biologist Barry Hansen. Once public comments are added, the EIS will be announced in the federal register. Then the tribes will wait for plan approval from the Bureau of Indian Affairs. Hansen said the tribes will begin working on an implementation plan for gill netting on Flathead Lake soon, and would like to implement it in 2014.

Last week, Deleray said Fish, Wildlife and Parks and the tribes are having discussions to try to resolve differences. Some of these differences involve interpretations of the prior co-management plan, biological information and the public review process.

“We’re hoping we can begin and work through another management planning process” to create a shared management direction, Deleray said.

The situation between the tribes and Fish, Wildlife and Parks has been “controversial, complicated and certainly has gotten animated at times,” Hansen said. “The tribes have patiently completed this process (of drafting a new environmental impact statement) with occasional Fish Wildlife and Parks involvement,” he said. “We’re moving forward, but we’re always willing to talk and compromise. We invited Montana Fish, Wildlife and Parks to participate, and they typically have chosen not to.”

In the meantime, Mack Days — which is a product of the first co-management plan — proceeds ahead with this year’s fall version set to begin Friday and run through Nov. 17. Between Mack Days — both the spring and fall versions — and other angling, some 78,000 lake trout were taken from Flathead Lake last year, Deleray said.

Fish, Wildlife and Parks is set to begin gill netting for adult lake trout on Swan Lake Monday. The netting will take place in the early morning and late evening hours until Oct. 25. Juvenile netting was completed earlier this summer.

Gill netting on Swan Lake is netting between 5,000 and 10,000 lake trout per year, Rosenthal said. Deleray notes that lake trout are not fully established in Swan Lake and that the gill netting is for suppression, not eradication.

There are several other gill netting projects across the West, including Yellowstone Lake in Yellowstone National Park, Lake Pend Oreille near Sandpoint, Idaho, and Quartz Lake in Glacier National Park. Netting at Yellowstone Lake has been going since 1996 and is killing 200,000 to 300,000 lake trout a year, Deleray said. Netting on Lake Pend Oreille started in 2006 and takes around 20,000 lake trout a year.

“Lake trout is pervasive in many, many lakes in the West and we learn from those examples,” Hansen said.

Biologists believe the lake trout population in Flathead and Swan lakes exploded in the 1980s after mysis shrimp were established. The shrimp were introduced to the region by Fish Wildlife and Parks in the late 1960s.

It remains to be seen whether Fish, Wildlife and Parks and the tribes can come to an agreement on gill netting in Flathead Lake, however. Deleray notes that Flathead Lake is 38 times larger than Swan Lake, so comparing them is like apples and oranges.

Email reporter@bigforkeagle.com.