South Fork bull trout numbers plummet
Westslope cutthroat trout swim in a gin-clear Glacier Park stream. A bull trout is at the bottom of the school.
By CHRIS PETERSON
Hungry Horse News
Montana Fish Wildlife and Parks will likely curtail the only legal bull trout river fishery in the state next season.
At its Nov. 12 meeting the Montana Fish and Wildlife Commission will take up proposed changes to the bull trout season and fish limits on the Hungry Horse Reservoir and the South Fork of the Flathead above the Hungry Horse Dam.
The proposed regulations would limit the take on the Hungry Horse Reservoir to one fish per angler each season, which, for bulls, is the third Saturday in May through Aug. 15.
The limit is currently two fish per angler per season.
On the South Fork of the Flathead River, which drains a huge portion of the Bob Marshall Wilderness, the season would be shortened to run from July 1 to July 31, with catch and release only. It is illegal to keep live bull trout for any reason.
It used to open on the third Saturday in May.
In both fisheries, anglers must also obtain and have in possession a free “catch card” which anglers are required to record certain data when fishing for the species, which is listed as threatened under the Endangered Species Act.
The Hungry Horse Reservoir/South Fork fishery is the only place to legally fish for bull trout in a river system.
FWP is also proposing restrictions near some key bull trout spawning areas in the Bob Marshall Wilderness. Including closing all angling within a 300-yard radius around the inlet (where the creek enters the lake) of Big Salmon Lake and closing all angling within 300 yards of the inlet on Big Salmon Creek.
In addition, angling would be prohibited from the mouths of Gordon Creek and Little Salmon Creek downstream 300 yards from June 15 to Sept. 30 on the South Fork.
Fishing for bull trout in South Fork tributaries is already illegal.
The proposed regulations come after biologists have found a precipitous drop in redd counts in the spawning streams on the South Fork and the reservoir.
For example, the White River had almost 80 redds in 2011, by 2024, it had less than 30. Gordon Creek, which is in the heart of the wilderness, had just under 80 redds a few years ago, by 2023 and again in 2024, it had about 25.
Because of their remoteness, wilderness streams are typically surveyed every three to five years, but after a very poor years in 2023, biologists went back and surveyed again this year, FWP fisheries biologist Leo Rosenthal explain.
The results were just as dismal, thus the reason for the regulation changes.
Redds are spawning beds in the gravel that bull trout excavate when they spawn. After they spawn, biologists, simply by wading streams, can count the redds and gauge how well adult fish are doing.
As the redd counts have dropped, the number of people fishing for bull trout in the South Fork of the Flathead has about tripled.
Since 2014, the number of anglers giving it a shot has risen to about 728 angling days a season. An angling day is one angler fishing one day.
According to catch card data, the number of fish being caught has risen from about 600 in 2017 to 1,200 in 2023.
Even with catch and release, some trout don’t survive the fight.
The pressure on the river fishery is seeing the biggest increase, Rosenthal noted. In the reservoir, it’s been fairly flat.
The U.S. Fish and Wildlife Service allowed the state to open the bull trout fishery in the reservoir and the South Fork in 2004. The fishery is unique because it doesn’t face the challenges of other fisheries from non-native species like lake trout, because the dam blocks upstream migration of lakers.
Lake trout have significantly damaged bull trout populations in the Flathead drainage below the dam, as non-native lake trout outcompete and also eat bull trout.
Still, a lower, but fairly stable population still exists in the North and Middle Forks of the Flathead, but fishing for them is illegal.
The hope is the curtailed bull trout regulations in the South Fork will help keep the fishery open.
“We’re trying to take an intermediate step rather than close (the South Fork) altogether,” Rosenthal said.
The amendments are being carried by Commissioner Pat Tabor. It will take them up at its Nov. 12 meeting, which starts at 8:30 a.m.
Interested parties can listen online at its website. Google Montana Fish, Wildlife and Parks Commission.