FWP holds off on gill netting in Swan Lake to see what happens if it stops program

For the first time in eight years, invasive lake trout were not gill-netted in Swan Lake in 2017.

The gill-netting operations, a collaborative operation primarily powered by Montana Department of Natural Resources and Montana Fish Wildlife & Parks, Region One was an effort to suppress Swan Lake’s growing lake trout population.

Other players included the Confederated Salish and Kootenai Tribes, US Fish & Wildlife Service, and Montana Trout Unlimited.

Lake trout have been blamed for lower populations of federally threatened bull trout in the Swan River watershed.

In the summer 2017 issue of Trout Line, newsletter of the Montana Council of Trout Unlimited, a story titled “FWP walks away from bull trout recovery efforts on Swan Lake” chastises the state agency for curtailing gill-netting.

Former Region One Fisheries Manager Mark Delaray countered by claiming there was no monitoring evidence showing that gill-netting was either resulting in fish population stabilities or producing a decline in lake trout and increase in bull trout.

“In other words,” said Delaray, “we just aren’t seeing a direct impact of gill-netting, so let’s see what no netting does.”

Moving from active gill-netting to more aggressive monitoring is consistent with the project’s original Environmental Assessment calling for years of netting, then year-to-year monitoring.

The project identified key lake trout spawning areas in Swan Lake.

Lake trout spawning areas have also been identified in Yellowstone Lake and there has been no shortage of creative and interesting ideas to suffocate eggs and target fry.

Ideas like balloon-delivered toxins, suffocating gels, induced siltation.

Cost of gill-netting in Swan Lake was about $150,000 per year.

Jerry Smalley’s Fishful Thinking column appears weekly in the Hungry Horse News.