The Confederated Salish and Kootenai Tribes have begun efforts to remove about 100,000 non-native lake trout from Flathead Lake in 2014, using gill netting, recreational angling and fishing contests to achieve the goal.
The decision to move forward with gill netting, which generated intense controversy between state and federal agencies, comes after an extensive environmental analysis of the effects of the practice, as well as other methods of lake trout suppression, which are outlined under the Flathead Lake and River Fisheries Co-Management Plan.
The 2014 plan sets a harvest target range of between 90,000 and 100,000 lake trout, and separates harvest by methods that include general recreational harvest, the Mack Days fishing contest and netting. This target figure represents about a 30 percent increase in the harvest measured over the last several years.
CSKT fisheries biologist Barry Hansen, who led the EIS process, said the tribes launched the first phase of netting during the last two weeks of April.
An experienced netting team trained tribal officials and, in eight days of netting, caught 5,232 lake trout. One bull trout was inadvertently captured and immediately released, so no mortality of bull trout resulted from the netting – a major benchmark of success.
Since the explosion of nonnative lake trout in Flathead Lake, the fish have outcompeted native bull trout populations, which have diminished.
Additionally, 2,487 lake whitefish were netted. Like Mack Days, the fish were donated to local food banks.
Hansen said the high rate of bycatch of whitefish was unfortunate, but that the crews adjusted the depth of their gill netting and significantly reduced the number of whitefish inadvertently caught.
The major points of contention between the state FWP and the tribes are whether bull trout populations in the Flathead River Basin have improved or stabilized since 2000, when the tribe and Montana Fish, Wildlife and Parks, which share fisheries management authority on Flathead Lake, adopted the Flathead Lake and River Fisheries Co-Management Plan with a goal of increasing the abundance of native bull trout and westslope cutthroat trout. The co-management plan, which expired in 2010, relied on recreational fishing pressure and contests to control lake trout abundance.
With the expiration of the 10-year management plan, the tribe began a National Environmental Policy Act process to develop a new science-based plan for a reduction of the bloated lake trout population in order to benefit native fish in the lake and river system.
Alienated from that discussion is the tribe’s longtime partner, the FWP, which separated itself from the process in a public sign of disapproval in March 2012. FWP, which is charged with the dual mission of maintaining a recreational fishery while supporting a stable, or “secure,” population of native species, says bull trout levels in the Flathead Basin are stable as defined by the previous co-management plan.
CSKT Tribal Council then recommended an aggressive reduction of nonnative lake trout in Flathead Lake, supporting a preferred alternative that would allow for the reduction of 75 percent of the adult lake trout population in Flathead Lake.
That alternative recommended a harvest of 143,000 lake trout every year, but Hansen said the tribes is moving forward cautiously as it continues to assess and evaluate their suppression methods.
He said the plan calls for removing 25,000 fish by way of the general recreational harvest, 45,000 fish through the spring Mack Days fishing contest, which ends May 18, and between 20,000 and 30,000 fish through gill netting.
The tribes prepared the plan to be a living document, subject to annual reviews and course corrections, rather than as a rigid and inflexible plan.
In addition, the plan describes changes in the fishery of Flathead Lake over time, and an incremental and transparent decision process that includes public involvement. Each year a team of fisheries professionals will review the results, followed by public scoping and review by the Reservation Fish and Wildlife Advisory Board, and concluding with a decision by the Tribal Council.
The netting was conducted under a permit issued by the U.S. Fish and Wildlife Service to address the incidental bycatch of bull trout, a threatened species
Wade Fredenberg of the USFWS monitored the netting for compliance and, after the review, stated that “the results were exactly what we expected – a high lake trout catch with virtually no bull trout bycatch. As a result, we continue to give our full support to this adaptive effort to incrementally reduce lake trout numbers.”