A vulnerability assessment tool for adapting Yellowstone cutthroat trout to
climate change on the Shoshone National Forest
Janine Rice1, Linda A. Joyce2, L. Scott Baggett2, Ray Zubik3, Bryan Armel3, Kerri Cary3, and Greg Bevenger4
YELLOWSTONE CUTTHROAT TROUT
Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) are a cold-water salmonid of special concern that has been
considered for listing under the Endangered Species Act. These native fish occupying Wyoming, Montana, Idaho, Utah, and
Nevada have experienced population distributions reductions to 42% of their historical range, of which 28% is occupied by
genetically unaltered populations (Gresswell et al 2011). This reduction has been attributed to the introduction of nonnative
fish species as well as anthropogenic activities, and the trout is expected to be sensitive to climate change (Rice et al. in
review). A case study on the Shoshone National Forest, WY has been conducted by the Forest Services’ West wide Climate
Initiative. One effort of this case study has developed a vulnerability assessment tool for Yellowstone cutthroat trout in
order to assist in the development of climate change adaptation strategies that support and guide planning and decisionmaking efforts .
METHODS
Conservation Project Planning
Conditions Don’t Improve
Conditions Improve
A customized vulnerability framework for Yellowstone
cutthroat trout was developed using GIS based data
indicators.
Sensitivity was represented by indicators for Debris flow
presence (GIS hazard maps) and Stream Slope (NHDPlus
and 30m DEM)
Adaptive Capacity was represented by indicators for
Barriers (protective and inhibiting) and Nonnative fish (WY
Game and Fish GIS Data), Diversions (WY Water Resource
Data), and natural and manmade water Storage (NHDPlus)
Modified from
Glick et al. 2011
IMPLICATIONS FOR MANAGEMENT
The Dead Indian Creek project removed nonnative fish species
from the main tributary of this natural barrier protected
stream and stocked genetically pure Yellowstone cutthroat
trout in 2010. This assessment result provided evidence that
Yellowstone cutthroat trout at the Dead Indian Creek
watershed may see improving habitat conditions over time.
Exposure was represented by indicators for Snow runoff %
(VIC Snow projections using A1B scenario, Wenger et al.
2010), and Stream Temperature (regression model using
A1B GCM temperature projections from Littell et al. 2011)
The Greybull and Wood Rivers did not show improving
conditions due to more rain-dominated runoff that offset
the positive effects of stream temperature warming.
Potential restoration projects in this area may not see
improving conditions under climate change.
Monitoring
Resource managers on the Shoshone used the vulnerability assessment tool to
guide monitoring planning by identifying areas of improving conditions and
higher adaptive capacity, and where gradients of vulnerability were defined in
watersheds. The North Fork Shoshone River was chosen as a focus area for a
monitoring project as it provided a range of vulnerability, adaptive capacity, and
climatic conditions. Many high elevations of this area showed improving
conditions that could be targeted for future conservation projects. Continued
monitoring could provide more detailed guidance as to when streams that are
currently too cold to support Yellowstone cutthroat trout may become thermally
suitable. The choice of this watershed for monitoring offered a further benefit as
gathered information would be representative of climate conditions and
potential vulnerabilities that may occur outside of the study area where
monitoring information does not exist.
Rankings for the indicators were averaged and categorized into 5 vulnerability categories.
RESULTS
The amount of High and Very High vulnerability classified stream miles decreased, while the amount of Low vulnerability
classified stream miles increased by 2040 and 2080. Higher elevation mountains tended to have improving conditions due to
warming stream temperatures and retention of snowmelt-dominated runoff, while lower elevation areas especially on the
east side of the Shoshone tended not to have improving conditions due to more rain-dominated runoff. The resulting
vulnerability conditions point to the Shoshone’s higher elevations serving as a refugia for Yellowstone cutthroat trout under
climate change.
REFERENCES
Gresswell, R. E. 2011. Biology, status, and management of the Yellowstone cutthroat trout. North American Journal of Fisheries
Management 31(5):782-812.
Glick, P., B. A. Stein, and N. A. Edelson, editors. 2011. Scanning the conservation horizon: A guide to climate change vulnerability
assessment. National Wildlife Federation, Washington, D.C.
Littell, J. S., M.M. Elsner, G. S. Mauger, E. Lutz, A.F. Hamlet, and E. Salathé. 2011. Regional Climate and Hydrologic Change in the
Northern US Rockies and Pacific Northwest: Internally Consistent Projections of Future Climate for Resource Management.
Available: http://cses.washington.edu/picea/USFS/pub/Littell_etal_2010/Littell_etal._2011_Regional_Climatic_And_Hydrologic_
Change_USFS_USFWS_JVA_17Apr11.pdf.
Rice, J., L. A. Joyce, L. S. Baggett, R. Zubic, B. Armel, K. L. Cary, G. Bevenger. In Review. A vulnerability assessment tool for adapting
Yellowstone cutthroat trout to climate change on the Shoshone National Forest, Wyoming. North American Journal of Fisheries
Management.
Wenger, S. J., C. H. Luce, A. F. Hamlet, D. J. Isaak, and H. M. Neville. 2010. Macroscale hydrologic modeling of ecologically relevant flow
metrics. Water Resources Research. [online serial] 46(9):W09513. doi:10.1029/2009WR008839
1 Western Water Assessment, University of Colorado, Rocky Mountain Research Station, 240 W. Prospect St., Fort Collins, CO 80526
USA. For more information email: jrice02@fs.fed.us
2 USDA Forest Service, Rocky Mountain Research Station, 240 W. Prospect St., Fort Collins, CO 80526 USA. Email: ljoyce@fs.fed.us
3 USDA Forest Service, Shoshone National Forest, 808 Meadow Lane Ave, Cody, WY 82414 USA.
4 USDA Forest Service, Intermountain Region, 324 25th Street, Ogden, UT 84401, USA.