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Copyright 2013 East Yellowstone Chapter Trout Unlimited. All rights reserved.                                                                      P.O. Box 3008, Cody, WY  82414
East Yellowstone Chapter Raises Funds for Research to
Save the Yellowstone Cutthroat
  • Lake Trout in Yellowstone Lake, Yellowstone National Park, are decimating the native Yellowstone Cutthroat
    Trout Population.
  • Gill netting in Yellowstone Lake has removed over 800,000 Lake Trout over the past 17 years (over 100,000 in
    2009, 150,000 in 2010, and 220,000 in 2011).  260,000 LT netted as of Sep 2012.
  • Millions have been spent on this valiant effort.
  • Yet, the Yellowstone Cutthroat Trout population has declined to 10% or less of its former level.
  • The Yellowstone Cutthroat is in trouble throughout its range.  It now occupies less than 43% of its historic
    range and is threatened by non-native species in many of the remaining watersheds.
  • Lake Trout are a growing problem in at least 14 other western waters, including Lake Pend Oreille, Flaming
    Gorge, Flathead Lake, and others.
  • There must be a better way to reduce Lake Trout populations and help the Yellowstone Cutthroat in
    Yellowstone Lake and other western waters.
  • Trout Unlimited, the National Park Service, the US Fish & Wildlife Service, and the US Geological Survey are
    partnering to fund research by Montana State University/USGS/USFWS to investigate and develop alternative
    methods to reduce or eliminate the Lake Trout in Yellowstone Lake.
Background - Yellowstone Lake /Yellowstone Cutthroat Trout Status  January 3, 2012
The Problem:
The Yellowstone cutthroat trout (YCT) now occupy
less than 43% of their historical range; in addition,
they are significantly hybridized in 1/3rd of the
remaining.

The Yellowstone Lake/upper Yellowstone River
system (YL) was once home to an estimated
4,000,000 YCT.  It was considered a stronghold for
genetically pure YCT’s and was considered relatively
safe from the impacts of climate change.  In addition,
it was considered a Keystone species for the entire
ecosystem; 40 other species are dependent on YCT.
Lake trout (LT) were officially discovered in 1994.  
They are overwhelmingly the most significant threat of
the triple threat to YCT subsistence:  lake trout,
drought, and whirling disease.

The NPS has been employing gill netting since 1995
and currently spend $1M annually on the effort.  To
date a total of over 800,000 LT have been netted;
220,000 in 2011 alone.  The LT population is now
estimated at 3-400,000 adult fish.
The current YCT population is unknown; but is certainly
no more than 10% of historical, probably <5%.
The Solution:
The YCT population in this system cannot be lost; and
need not be lost.  A Scientific Review Panel in 2008
made 4 major recommendations to NPS.  These were
renewed in June of this year. Basically, these
recommendations require increased suppression
(netting) of LT, while developing scientific approaches
to population estimates of both species, movement
patterns of LT, LT spawning site identification by a
robust telemetry study, experimentation with
alternative technology to target LT eggs, and periodic
review by the scientific community.
Major strides have been made in the past few years by
the NPS in their approach.  Yellowstone Park
administration changed over the winter with Daniel
Wenk being named Superintendent.  A comprehensive
fisheries management EA was published which sets
benchmarks for LT removal and YCT recovery.
The NPS netting effort was significantly increased
by the hiring of a commercial fishing crew from
Wisconsin.  The NPS has formed an alliance with
outside governmental agencies and with NGOs
(Trout Unlimited, Greater Yellowstone Coalition,
National Parks Conservation Association) to tackle
the problem, including the acceptance of financial
support and input.  The USGS began a major
research effort in 2008 to identify alternative
suppression technology – targeting recruitment.  
Some of that technology is now ready to scale-up.  
Electro-shocking of LT eggs was used this past fall
for the first time on Lake Pend Oreille.  Results of
that study are due this winter.  The most significant
advancement has been the start of a three year
hydro-acoustic telemetry study as a joint effort of
all parties to identify lake trout movement patterns
and spawning beds.
Future Direction:
The key to YCT recovery is major suppression
of LT (they will probably never be eliminated)
while at the same time, cutting off recruitment
into the LT population.  Central to this goal, is to
know the location of their spawning beds and
movement patterns, thus a hydro-acoustic
study was initiated on August 16, 2011.  A total
of 141 hydro-acoustic tags were surgically
implanted into lake trout.
Yellowstone Lake Receiver
Locations

Click map to enlarge.
Implanting hydro-acoustic tag
into lake trout "Judas Fish".
Movements of these fish are being monitored by 40
receivers strategically located around the lake. Data  
will be analyzed this winter and reported in February
at a meeting of the Yellowstone Lake working group.
This 3 year telemetry effort requires a significant
NPS, USGS and NGO commitment of money,
research time, and support. The NGOs have
committed to raising, as a minimum, an additional
$85,000 by spring 2012 to support year 2 of the study.
 The money will buy an additional 100 standard hydro-
acoustic tags at $400 each, 50 depth recording
hydro-acoustic tags at $750 each, and needed
supplies. The NGO’s already donated $40,000 to get
the project started in 2011. The NPS has committed
to assisting with this study and to continuing the
expanded LT suppression program. The USGS has
committed to research staffing and project
coordination.
Yellowstone National Park Native Fish Restoration Project - Status Report, February 23, 2013
On February 21st the Working Group that has been coordinating the efforts of the multiple NGO’s and agencies
engaged in the effort, met at Mammoth Hot Springs. This meeting reviewed the progress of netting suppression,
telemetry studies, population trends of both Yellowstone cutthroats and lake trout, fundraising status for both
short term suppression and longer term ova suppression, and directions for the upcoming season.

As Project Manager from Wyoming TU for the Yellowstone Lake work, I couldn’t be happier. Cooperation between
the diverse groups has never been so strong and the indicators for “success” have never been better.

Lake trout suppression on Yellowstone Lake is now seen as a two pronged effort. One can’t succeed without the
other. In the short term, gill netting has been expanded to reach a critical milestone of units of effort (basically the
length of nets in the water for a specified number of days) and a critical milestone of lake trout removal which will
lead to a population crash. This coming season should see even higher levels of gill netting, and subsequent lake
trout removal, as the contract netting company adds a third boat to the fight. Trap netting will continue to target the
larger, spawning age fish in shallow water. We may finally be at a level of lake trout removal that reverses the
course of population expansion. In the longer term, ova suppression is now seen as an important component of
total lake trout control rather than a separate research study.

The telemetry program, that we all have helped fund, is now starting to pay real dividends. The statistician that was
hired in November is really starting to pick apart the overwhelming amount of telemetry data. His conclusions are
just starting to guide the netting as depth and temperature preferences, as well as movement patterns of the lake
trout by season, are being understood. In addition, his analysis has pointed to several potential new spawning
beds around the lake. Meanwhile, the VPS (Vemco Positioning System) array system at Carrington Island has
pinpointed the exact location and extent of that spawning bed as well as the timing of its use by the lakers.

Experiments are also underway to utilize new technology to kill those lake trout eggs at Carrington. Electro-
shocking continues to be considered the best methodology as two outside contractors are being considered for
specific systems. In addition, the NPS employed vacuum technology on a limited basis at Carrington last fall.

All indicators of both lake trout and YCT populations are pointed in the right direction. We are a long way from
winning back this system; however, we are definitely going in the right direction after so many years of decline.
Every parameter from lake trout CPUE (catch per unit effort), to distribution netting of both species, to angler
surveys indicate positive trends.

We cannot let up, however. We all know that there is a long way to go, and we all know that the trend will reverse
back without constant diligence. Our fundraising is a critical part of that. The telemetry season of 2013 is so
important. Our hydro-acoustic tags that we all helped purchase have only limited battery life remaining. We must
take advantage of that battery life this year by deploying as many VPS arrays on potential spawning beds as
possible. That takes money. The NGO partners are currently trying to raise $118,000 to support this year’s work.
We currently have $43,000. If you personally or your chapter can dig even deeper, we can meet our goal. Consider
sending in whatever you can to “Save the Yellowstone Cutthroat” c/o WY TU, 250 1st St, Lander, WY 82520.

Submitted by Dave Sweet, davidps@tritel.net.
100% of your tax deductible contribution goes to the study.
Make Checks payable to "Save the Yellowstone Cutthroat".
Send to:  Trout Unlimited, P.O. Box 3008, Cody, WY  82414.

For more information please call Dave Sweet, campaign
coordinator, (307)527-9959.
davidps@tritel.net
Sponsor a "Judas Fish" and track it on line...
Donate a Lake Trout telemetry tag ($400) for Yellowstone Lake
New UW Research Shows Grizzly Diet Shift
Hits Elk Herds
May 15, 2013 — A decline in native Yellowstone
cutthroat trout due in part to the introduction of nonnative
lake trout has driven a shift in the diets of grizzly bears
that helps explain losses in some migratory elk herds in
the greater Yellowstone area, according to new research
published today.  read more

Fewer Trout Hurt YNP  Raptors
May 13, 2013 - In an ecological chain reaction, an
overabundance of non-native mackinaw in Yellowstone
Lake is hurting the cutthroat trout population, which in
turn makes slim pickings for osprey.  read more