ambitious, long-term effort to restore native fisheries in alpine lakes above
Montana’s South Fork Flathead River drainage — a major tributary in the
Columbia River headwaters — is coming to a successful conclusion this fall.
wasn’t necessarily the public view when the project was pitched more than 10 years
ago. The proposed use of Rotenone toxin to purge non-native rainbows or
cutthroat-rainbow hybrids, and other aspects of the project, were met with
suspicions and concerns.
were a myriad of concerns that we were dealing with,” said Matt Boyer, science
program manager for Montana Fish, Wildlife and Parks in Kalispell. “We were
proposing a native fish restoration project on waters that were a really
popular sport fishery. Not only that, we were doing it with Rotenone … We had
to, right out of the chute, start an education program to sort of teach people
what we were proposing. Some of it was to address the concern that we were just
going to destroy the fishery.”
Rotenone has been used for decades in scattered efforts that were deemed
successful, it hadn’t been applied as a major tool in a landscape-scale
conservation project targeting 19 alpine lakes. Seven of those were treated
with genetic swamping, basically overwhelming the non-native and hybrid fish
that were present. Rotenone was used where swamping approach was not expected
to succeed. And there were valid questions about how the chemical would impact
insects and amphibians, Boyer said.
prompted in-house research involving field surveys measuring the occurrence of
amphibians and insects in and around lakes that were proposed for treatment.
The project was rolled out with an adaptive management strategy where the
lessons learned from initial target lakes could be applied to the remaining
was a conservative, lake-by-lake approach, which was a critical part of its
eventual acceptance and progression, Boyer said, adding that scientifically, it
was the best approach as well.
aquatic insects been decimated with lasting effects, for instance, the work
would be considered entirely counterproductive.
would defeat the purpose of the work. We wanted to build a track record of
successes rebuilding these native fisheries,” Boyer said.
state’s amphibian work has since become a topic of its own with publication in
the North American Journal of Fisheries.
didn’t find any affect or change on a lake after Rotenone treatment,” Boyer
said. That is attributed partly to the timing of the fall treatments, along
with repopulation of lakes from surrounding habitat, and safeguard practices,
such as using a chemical to neutralize the effects of Rotenone, which is also
degraded by sunlight.
and his team also had to demonstrate the recovery of the fisheries after being
planted with genetically pure west slope cutthroat trout derived from the avant
garde Sekokini Springs conservation hatchery located near the town of Hungry
Horse and Hungry Horse Dam at the foot of the South Fork Flathead drainage.
this project and many others, Boyer said, it has been important to dispel the
wide held belief that “a trout is a trout.” Extensive research in the Columbia
Basin involving salmon have shown that hatchery fish lack the survival and
reproductive instincts that wild fish have. Similar findings apply to rainbow
trout raised from a genetic brood stock, compared to the wild fish raised at
Sekokini Springs that were derived from South Fork drainages. Fish are cycled
through the hatchery with the intent that “we have as minimal a fingerprint on
these fish as possible,” Boyer said.
approach at Sekokini Springs, which has been gradually established and
developed during the general timeline of the alpine lakes work, has received
lots of attention from far and wide. “Using local sources of trout, instead of
a general brood stock, in many cases can be a smart way to do things, Boyer
for re-establishing angling fisheries — one of the main goals of the project —
there has been great success, as measured by Fish, Wildlife and Parks and
anglers who frequent the lakes.
varies some from lake-to-lake, depending on how much nutrients are present, but
generally they have been restored within two to three years, with catch rates
and size distribution of fish that we saw prior to the project.”
the work was staggered over a decade, there has been ample alpine lake angling
opportunities in the project area throughout.
Boyer contends the project has been highly cost effective, with a price a tag
of about $5 million from the Bonneville Power Administration’s Fish and
Wildlife Mitigation Fund.
goal is to create self-sustaining fisheries” that do not need to be augmented
with fish plants as much as before, Boyer said. “All these lakes have spawning
habitat. The intent is that we will be able to back off the stocking.”
work has caught the attention of fishery managers elsewhere. Glacier National
Park is developing a Fisheries Management Plan with guidance from the alpine
lakes project. Boyer said the plan is being developed in a way that would allow
the use of Rotenone or other piscicides in the park. Nearly all of the lakes on
Glacier’s western flank have been invaded by non-native lake trout with adverse
impacts on native species, such as bull trout.
emphasized that Glacier’s fisheries plan will be developed through an entirely
new and separate public involvement and environmental review process.
is also collaborating with the Confederated Salish-Kootenai Tribes for
conservation work on the Flathead Reservation, and Boyer has been working with
Parks Canada and the provinces of Alberta and British Columbia.
final leg of the project will involve Rotenone treatment of the largest lake in
the project area, 148-acre Sunburst Lake, which will be carried out Sept. 3-9
with the help of personnel from the Alberta provincial government and Parks
the work has been carried out on lakes inside wilderness boundaries, there have
been logistical challenges. The Sunburst Lake crew will hike in, and a
helicopter will be used for transporting equipment to the lake, which requires
specific approval from the U.S. Forest Service.
is proud it has been a landscape-scale project, rather than a costly, ongoing
piece-meal approach. “This isn’t suppression,” he said. “It’s an approach where
you can accomplish conservation over a large landscape scale, with big benefits
CBB, Dec. 18, 2015, “Isolated Rearing Facility For Native Fish Key Component In
Montana Effort To Reduce Hybridization” http://www.cbbulletin.com/435727.aspx
CBB, Dec. 18, 2015, “Montana’s South Fork Flathead Cutthroat Conservation
Project – Purging Non-Native Fish” http://www.cbbulletin.com/435728.aspx