Thomas E. McMahon
Department of Ecology
Fish and Wildlife Ecology and Management Program
Montana State University
Bozeman, Montana 59717
Office: Lewis 406A, phone 406/994-2492
Barbara, Aquatic Biology, 1975
MS, University of
PhD, University of
Professor of Fisheries, Montana State University
Sabbatical Leave: Fall
2006: University of Washington, School of Ocean and Fishery Sciences
(sponsor: Dr. Thomas Quinn)
University of Arizona,
Resources (sponsor: Dr. William Matter)
1997-2002 Associate Professor
Assistant Professor of Fisheries, Fish and Wildlife Program, Montana
Assistant Professor, Oregon State University, and Coordinator,
Project, Coastal Oregon Productivity Enhancement (COPE) Program,
of Forestry and
Marine Science Center, Newport, OR
Postdoctoral Fellow/Visiting Scientist, Pacific Biological Station,
Department of Fisheries and Oceans,
British Columbia (Supervisor: Dr Gordon Hartman)
Fishery Biologist, Habitat Evaluation Program, U.S. Fish and Wildlife
Center, Fort Collins, Colorado
Fishery/Hydrological Technician, U.S. Forest Service, Range and
Wildlife Lab, LaGrande, Oregon
Graduate Research Assistant, U of Arizona
Fishery Technician, U.S. Fish and Wildlife Service, Juneau, Alaska
Technician, Targhee National Forest, Island Park, Idaho
- Introduction to Fish
Habitat Management, FWL
513, Even years
(Bitterroot bull trout,
Research Interest: Conduct applied research directly related to current
questions in fisheries management and testing of ecological
on which fishery management is based.
stream salmonid ecology and
conservation of native
life history/otolith microchemistry of salmonids
winter ecology of
- Thermal Requirements of Westslope
Cutthroat Trout (Wild
Fish Habitat Initiative, Montana Water Center)
- Factors Affecting the Relative
and Resident Life History Forms among Bull Trout Populations (AVISTA
and US Fish and Wildlife Service)
- Does Fire Favor Nonnative Fishes? (USFS,
Mountain Research Station,Mike Young, USFS Rocky Mountain Research
- Factors Limiting Recruitment of Wild
in Hebgen Reservoir, MT (PPL Montana and Montana FWP)
- Role of Culverts in Fragmenting Fish
within a Large Drainage Basin in Western Montana (Montana Dept of
co-PI, Joel Cahoon MSU BioResources Engineering Dept)
- Interaction of Life History, Fish
Risk on Population-level Effects of Whirling Disease on Missouri River
Rainbow Trout (National Partnership on the Management of Wild and
Cold Water Fisheries)
- Growth and Survival Temperature
Trout (National Council for Air and Stream Improvement)
- Susceptibility of Montana’s
Disease Infection (Whirling Disease Foundation)
- Status of Sauger in Montana
Wildlife, and Parks)
- Microchemical Analysis of Otoliths to
Life-History Patterns in Interior Salmonids (US Forest Service,
Mountain Research Station)
- Origins of Nonnative Lake Trout in
National Park using Otolith Microchemistry (Yellowstone National
A. Munro PI)
- Spawning and Rearing Ecology of
Rainbow Trout in Relation to Whirling Disease Infection Risk
Partnership on the Management of Wild and Native Cold Water Fisheries)
Reports and Presentations
S.R. Thorrold, T.E. McMahon, and B. Marotz. 2012. Estimating
westslope cutthroat trout (Oncorhychus
movements in a river network using strontium isoscapes. Canadian
Journal of Fisheries and Aquatic Sciences 69:906-915. PDF
see news article
- Neudecker, R.A.,
T.E. McMahon, and E.R. Vincent. 2012. Spatial and temporal variation of
whirling disease risk in Montana spring creeks and rivers. Journal
of Aquatic Animal Health 24:201-212. PDF
- McMahon, T.E. 2011. Review
of NMFS Draft Recovery Plan for the North
Central California Coast
Steelhead, California Coastal Chinook
Steelhead. Report to the Center
for Independent Experts.
- Guy, C.S., T.E.
McMahon, W.A. Fredenberg, C.J. Smith, D.W. Garfield, and B.S. Cox.
overlap of bull trout and lake trout in recent sympatry in Swan
Lake, Montana. Journal of
Fish and Wildlife Management 2:183-189. PDF
- Sestrich, C.S.,
T.E. McMahon, and M.K. Young. 2011. Influence of fire on
and nonnative salmonid populations and habitat in a western Montana
basin. Transactions of the American Fisheries Society 140:136-146.
T., J. Robison-Cox, J. Rotella, T. Horton, and B. Kerans. 2010. Trout
population responses to whirling disease epizootics in Montana rivers.
Pages 195-202 in
Proceedings of the Wild Trout X Symposium, Sept 2010, West
Yellowstone, MT. PDF
T., J. Robison-Cox, J. Rotella, T. Horton, and B. Kerans. 2009. A
before-after, control-impact comparison of the effects of whirling
disease epizootics on trout population dynamics in Montana
rivers. Final report, National Partnership on Management of Wild
and Native Coldwater Fisheries, Montana Water Center. 112 p. PDF
C.C., T.E. McMahon, D.
Belcer, and J.L. Kershner. 2009. Spatial and temporal
spawning dynamics of native westslope cutthroat trout (Oncorhynchus
clarkii lewisi), introduced rainbow trout (O. mykiss), and
their hybrids. Canadian Journal of Fisheries and Aquatic Sciences
McMahon, M.C. Boyer,
and R.E. Gresswell. 2009. Local habitat,
biotic factors influencing the spread of
hybridization between native westlope cutthroat trout and introduced
rainbow trout. Transactions of the American Fisheries Society
McMahon, M.L. Taper, S. Painter, R.F. Leary, and F.W. Allendorf.
2009. Hybridization rapidly reduces fitness of a native trout
in the wild.
Biology Letters 5:328-331. PDF
McMahon, J.E. Cahoon, and M. Blank. 2009. Assessment
trout passage through culverts in a large Montana drainage during
summer low flow. North American Journal of Fisheries Management
N., and T.E. McMahon.
2009. Comparison of
fin rays, scales and otoliths for estimating age and growth of bull
trout, Salvelinus confluentus.
Fisheries Management and Ecology 16:155-164. PDF
T.E., B.A. Bear, and
Zale. 2008. Use of an annular chamber for testing thermal
westslope cutthroat trout and rainbow trout. Journal of Freshwater
Ecology 23:55-63. PDF
T.E., A.V. Zale,
Selong, and R. Danehy. 2007. Temperature and competition between
and brook trout: a test of the elevation refuge hypothesis.
Transactions of the American Fisheries Society 136:1313-1326. PDF
E.A., T.E. McMahon, and
Comparative thermal requirements of westslope cutthroat trout and
rainbow trout: implications to species interactions and development of
thermal protection standards. Transactions of the American Fisheries
T., and W.J.
habitat selection, emigration, and population dynamics of freshwater
fishes: a synthesis of ideas and approaches. Invited presentation to
International Symposium on Behaviour and Ecology of freshwater fish:
Linking Ecology and Individual Behaviour, Danish Institute of
Freshwater Fisheries Research,
Silkeborg, Denmark. Aug 2004. Ecology of Freshwater Fish
15: 200-210. PDF
N.D., and T.E.
Effect of pelvic fin ray
removal on survival and growth of bull trout. North American Journal of
Fisheries Management 26:953-959. PDF
T.E. 2006. Review
NOAA-Fisheries Biological Opinion on Effects of Proposed Central Valley
(CA) Project Changes on Listed Fish Species. NOAA Southwest Fisheries
and Center for Independent Experts. PDF
A.R., T.E. McMahon,
J.R. Ruzycki. 2006. Where did they come from? Natural
chemical markers identify source and date of lake trout introduction in
Yellowstone Lake. Yellowstone Science 14(2): 4-12. PDF
- Blank M, Cahoon J, Burford D,
McMahon T and Stein O. 2006. Studies of fish passage through culverts
in Montana. IN: Proceedings of the 2005 International Conference on
Ecology and Transportation, Eds. Irwin CL, Garrett P, McDermott KP.
Center for Transportation and the Environment, North Carolina State
University, Raleigh, NC: pp. 647-661. URL: http://escholarship.org/uc/item/7q19086f
M.E., A.V. Zale, T.
McMahon, and B.J. Schmitz. 2005. Seasonal
movements, habitat use, aggregation,
exploitation, and entrainment of sauger in the lower Yellowstone River:
empirical assessment of factors affecting population recovery. North
American Journal of Fisheries Management 25:1550-1568. PDF
D.A., and T.E.
McMahon. 2005. A
lightweight modification of the McNeil core substrate sampler.
Journal of Freshwater Ecology 20:795-797. PDF
A.R., T.E. McMahon,
2005. Natural chemical markers identify source and date of introduction
exotic species: lake trout (Salvelinus namaycush) in Yellowstone
Lake. Canadian Journal of Fisheries and Aquatic Sciences 62:79-87. PDF
G.F., and T.E.
of fish reproduction and some implications of forestry
Pages 143 to 168 IN T.G. Northcote and G.F. Hartman (eds.).
and Forestry- Worldwide Watershed Interactions and Management.
C.F. Jr., T.E.
Thompson. 2003. Local habitat, watershed, and biotic
associated with bull trout occurrence in Montana streams.
of the American Fisheries Society 132:1053-1064. PDF
A.R., T.E. McMahon,
2003. Evaluation of batch marking small rainbow trout with coded
wire tags. North American Journal of Fisheries Management
D.C., T.E. McMahon,
Vincent. 2002. Relation of spawning and rearing life
of rainbow trout and susceptibility to Myxobolus cerebralis
in the Madison River, Montana. Journal of Aquatic Animal Health
M.L., T.E. McMahon,
2002. Decline of the migratory form in bull charr, Salvelinus
and implications for conservation. Environmental Biology of Fishes
J.H., T.E. McMahon,
2001. Effect of temperature on growth and survival of bull trout,
with application of an improved method for determining thermal
in fishes. Transactions of the American Fisheries Society
T.E., and W.M.
Status of sauger in Montana. Intermountain Journal of Sciences
M.J., T.E. McMahon,
2000. Diel habitat partitioning by bull charr and cutthroat trout
during fall and winter in Rocky Mountain streams. Environmental
of Fishes 59:79-89. PDF
- McMahon, T.E. 1999. Status of
sauger in Montana. Final Report to Montana Fish, Wildlife and Parks,
Helena. 94 pp. PDF
M.J., T.E. McMahon,
1998. Role of stream ice on fall and winter movements and habitat use
bull trout and cutthroat trout in Montana headwater streams.
of the American Fisheries Society 127:223-235. PDF
Managers as Shamans. Presidents Corner, The Outlet, Montana
Chapter American Fisheries Society newsletter. PDF
T.E., A.V. Zale,
Aquatic Habitat Measurements. Pages 83-120 IN B. Murphy and D. Willis,
(eds.). Fisheries Techniques, 2nd edition. American Fisheries
T.E., and D.H.
Walleye and northern pike: boost or bane to Northwest fisheries.
Fisheries 21(8):6-13. PDF
S.R., T.E. McMahon,
Effects of electrofishing pulse shape and electrofishing-induced spinal
injury on long-term growth and survival of wild rainbow trout.
American Journal of Fisheries Management 16:560-569. (Received best
award for 1996, NAJFM) PDF
J.P., T.E. McMahon,
Spatial variation in spawning habitat of cutthroat trout in a
stream basin. Transactions of the American Fisheries Society
C.L., and T.E.
of a TMDL (total maximum daily load) to reduce nonpoint source sediment
pollution in Deep Creek, Montana. Montana Dept. of Environmental
Quality Rept. 103 pp.
T.E., S.R. Dalbey,
and P.Byorth.1996. Field evaluation of visible implant tag
by brook trout, cutthroat trout, rainbow trout, and Arctic
North American Journal of Fisheries Management 16:921-925.
T.E., and S.H.
of largemouth bass Micropterus salmoides at different light
implications for time and depth of feeding. Journal of Fish
46: 759-767. PDF
T. 1992. Potential
of walleye to the fishery of Canyon Ferry Reservoir and surrounding
Montana Fish, Wildlife and Parks Rept.
T.E., and L.B.
habitat use, and movements of coho salmon smolts (Oncorhynchus
during seaward migration. Canadian Journal of Fisheries and
Sciences 49: 1478-1485. PDF
T.E., and D.S.
Effects of fire on fish and wildlife. Pages 233-250 IN J. Walstad
(ed.). Natural and Prescribed Fire in Pacific Northwest
Oregon State University Press, Corvallis.
T.E., and G.F.
of cover complexity and current velocity on winter habitat use by
coho salmon (Oncorhynchus kisutch). Canadian Journal of
and Aquatic Sciences 46: 1551-1557. PDF
L.B., T.E. McMahon,
1989. Stream temperatures and interannual variability in the emigration
timing of coho salmon smolts and fry and chum salmon fry from Carnation
Creek, British Columbia. Canadian Journal of Fisheries and
Sciences 46: 1396-1405.
W.J., R.W. Mannan,
J.H. Menke, and J.C. Tash. 1989. A laboratory approach for
emigration. Ecology 70: 1543-1546.
T.E., and J.C.
analysis of the role of emigration in population regulation of desert
macularius). Ecology 69: 1871-1883. PDF
T.E., and G.F.
in the degree of silvering of wild coho salmon smolts migrating seaward
from Carnation Creek, British Columbia. Journal of Fish Biology
1987. Saying that logging is either 'good' or 'bad' for
doesn't tell you how to manage the system. Forestry Chronicle 63:
T.E., and R.R.
of the fishes of the Rio Sonoyta Basin, Arizona and Sonora,
Proceedings Desert Fishes Council 13-15: 237-245.
T.E., and J.C.
of formalin (buffered and unbuffered) and hydrochloric acid on fish
Copeia 1979: 155-156.
T.E., and J.C.
the chemical senses by threadfin shad to detect food, predators,
and conspecifics. Journal of Fish Biology 14: 289-296.
T.E. and B.Kynard.
antitranspirant by mosquitofish. Southwestern Naturalist
for creek chub, channel catfish, walleye, warmouth, spotted bass, coho
salmon, and chum salmon. USFWS Biol. Rept. Series.
Montana Fish, Wildlife, and Parks, 2003-2007.
member of Excellence
in Fisheries Education Award committee, 2006-2007.
nomination, Journal of
Section, American Fisheries Society, 2003-2005.
the Year award,
of the American Fisheries Society, 2002.
American Fisheries Society, 1996-1999 (consecutive terms for
vice president, president, past-pres.).
Paper award, North
Past Graduate Students (date
& present employment)
- David Dockery, (MS),
Maintaining Migratory Pathways of Imperiled Large River and Small
Stream Prairie Fishes in the Face of Climate Change and Energy
- Mariah Mayfield, Assessment of
Fisheries Restoration Potential of
the Upper Clark Fork Superfund Site: Spawning and Rearing Habitat Use
and Movements of Trout
in Relation to Environmental Factors in the Mainstem and Selected
Tributaries. (MS) (Recipient of EPA STAR Fellowship, 2010-2012)
- Joe Naughton
(MS); Ted Sedell (MS)
Coadvisor with Bob Gresswell, USGS Northern Rocky Mountain
Advisor to Graduate Students in Masters of Science in Science Education
Program at MSU:
Dale Spady, high school science
teacher, Thousand Oaks, California (in progress)
Miles McGeehan, high school
teacher, Vail, Colorado (in progress)
James Stuart, high school
science teacher, Bozeman, Montana (completed degree, 2010)
Todd Samson, middle school
teacher, East Helena, Montana (completed degree, 2009)
Patty Weaver, science
Pennsylvania (completed degree, 2009)
Lisa Skilang, science teacher,
Mission, Iowa (completed degree, 2008)
Lisa Hawkins, science teacher,
Taejon High School, Seoul, South Korea (completed degree, 2007)
Cary Rosillo, science teacher, West Palm Beach (FL) middle
school (completed degree, 2007)
- Clint Smith, (MS, 2011) Fishery Biologist, Montana Fish,
Wildlife, and Parks, Great Falls.
Thesis: Assessment of
Altered Rearing Environments on Survival and Performance of
Hatchery-Reared Trout: Implications for Cutthroat Trout Reintroduction
Ertel (MS, 2011), Fishery Biologist, Yellowstone National Park.
Thesis: Distribution, Movements, and Life History
Characteristics of Yellowstone Cutthroat Trout in the Upper Yellowstone
River Drainage. Available at: http://etd.lib.montana.edu/etd/view/
2008), Research Aquatic Ecologist, US Geological Survey, Northern
Rocky Moutain Science Center, Glacier
National Park. Dissertation: Behavioral, Ecological, and Fitness
Consequences of Hybridization between Native Westslope Cutthroat Trout
and Nonnative Rainbow Trout. (Available
Solcz (MS 2007) Fishery Biologist, Hydroacoustics Technology
Inc. (HTI), Seattle, WA. Thesis:
Assessment of Culvert Passage of
Yellowstone Cutthroat Trout in a Yellowstone River Spawning Tributary
Using a Passive Integrated Transponder System (Available at: http://etd.lib.montana.edu/etd/view/ )
Rosenthal (MS 2007) fishery
biologist, Montana Fish, Wildlife and Parks, Kalispell, MT.
Evaluation of Distribution and Fish Passage in Relation to Road
Culverts in Two Eastern Montana Prairie Streams.(Available: http://etd.lib.montana.edu/etd/view/
- Nik Zymonas
(MS 2006), research fishery biologist, Oregon Department of Fish and
Wildlife, Corvallis, OR Thesis: Age Structure,
and Factors Affecting the
of Life History Forms of Bull Trout in the Clark Fork River Drainage,
Montana and Idaho. (Available: http://etd.lib.montana.edu/etd/view/
) (Winner 2004 Student Writing
Fisheries Society for his article in Fisheries
"Alternative Lifestyles: Bull Trout
Strategies in the Northern Rockies")
Watschke, (MS 2006),
fishery biologist, Beaverhead-Deer Lodge National Forest, Ennis,
Thesis: Assessment of Tributary Potential for Wild Rainbow Trout
Recruitment in Hebgen Reservoir, Montana. Available at: http://etd.lib.montana.edu/etd/view/
Sestrich (MS 2005),
fishery biologist, Gallatin National Forest, Livingston, MT.
Thesis: Changes in Native and Nonnative Fish Assemblages and Habitat
Following Wildfire in the Bitterroot River Basin, Montana. Available
- Beth Bear
(MS 2005), fishery biologist,
Wyoming Game and Fish Department, Laramie, WY. Thesis: Effects of Temperature on Survival and
Growth of Westslope Cutthroat Trout and Rainbow Trout: Implications for
Conservation and Restoration. Available
Burford (MS 2005), fishery
biologist/stream restoration specialist, Oasis Environmental,
Livingston, MT. Thesis:
An Assessment of Culverts as Fish
Passage Barriers in a Montana Drainage Using a Multi-tiered Approach.
Munro (PhD 2004), postdoctoral
microchemistry at University of Adelaide, School of Ocean Sciences,
Australia. Present position: Alaska Department of Fish and Game,
Commercial Fisheries Division, Anchorage. Dissertation:
Identification of Life History
Variation in Salmonids Using Otolith Microchemistry and Scale Patterns:
Implications for Illegal Introductions and for Whirling Disease in
Missouri River Rainbow Trout.
Aasheim (MS 2004),
Blackfoot Watershed Restoration Coordinator, Trout Unlimited, Missoula,
Downing (MS 2000),
fishery biologist, Beaverhead-Deerlodge
Forest, Wisdom, MT
Nelson (MS 1999), Native Species Coordinator, Montana
Fish, Wildlife and Parks, Helena, MT
Bowersox (MS 1998), Syracuse NY
school science teacher
Handy (MS 1997), GIS specialist, Trout Unlimited
Endicott (MS 1996), Yellowstone cutthroat trout recovery
coordinator, Montana Fish, Wildlife and Parks, Livingston MT
Rich (MS 1996), Purdue University
PhD, current position: US Fish and Wildlife Service, National Fish
Habitat Plan Coordinator, Anchorage, Alaska.
Jakober (MS 1995), fishery
Dalbey (MS 1994), Regional Fisheries Manager/Supervisor, Montana
FWP, Glasgow, MT
- Jim Magee
(MS 1993), Arctic grayling recovery coordinator,
Montana FWP, Dillon, MT
Ireland (MS 1993), Director of fish and
wildlife program, Kootenai Tribe of
Montana Chapter American
Fisheries Society (AFS)--(includes job links)
AFS homepage--(includes job links)
Montana Fish, Wildlife, and Parks
Whirling Disease Foundation
Lab, Montana State University
Montana Water Resources Center
Back to the MSU
Fish and Wildlife Program , the MSU Ecology Department,