I am a fisheries ecologist, blending basic and applied ecology at the intersection of fisheries science, fish biology, and aquatic ecology. While exploited fishes may be a focus of some of my research, I adopt a holistic perspective that includes all kinds of fishes and interdependent organisms, and considers the roles of humans as components of ecosystems. My overall goal is to contribute to the conservation and management of aquatic ecosystems through teaching, research and outreach.

CV | Email: brett.johnson@colostate.edu | Office: 233 Wagar

PhD Zoology, University of Wisconsin, 1993

MS Zoology, The Ohio State University, 1986
BS Zoology, University of Wisconsin, 1983

Research Interests
I am interested in food webs, lake and reservoir ecology, effects of nonnative species, fisheries management, water quality, contaminant ecology, and effects of climate.
I apply a wide variety of approaches including field sampling, modeling, field and lab experiments, classical fisheries biology techniques, stable isotopes, eDNA, and otolith microchemistry. My research benefits from collaboration with agencies including Colorado Parks and Wildlife, Wyoming Game and Fish, U.S. Bureau of Reclamation, U.S. Fish and Wildlife Service, Northern Colorado Water Conservancy District, and others.

FW 300 Biology & Diversity of Fishes. Anatomy, physiology, evolution, systematics, ecology, zoogeography, and conservation biology of fishes. 

FW 301 Ichthyology Laboratory. Fish anatomy, identification and ecology.
FW 401 Fishery Science. Senior capstone course stressing quantitative aspects of fishery biology, conservation and management.

Professional Experience
Professor, Dept. of Fish, Wildlife and Conservation Biology, Colorado State University, 2004-
Visiting Professor, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany, 2007.
Associate Professor, Dept. of Fishery and Wildlife Biology, Colorado State University, 1998-2004.
Assistant Professor, Dept. of Fishery and Wildlife Biology, Colorado State University, 1992-1998.
Fisheries Manager, Wisconsin Dept. of Natural Resources, Madison, Wisconsin, 1987-1992.
Research Assistant, Cooperative Fishery Research Unit, UW-Stevens Point, 1986-1987.
Research Specialist, Wisconsin Dept. of Natural Resources, Spooner, Wisconsin, 1986-1987.

Recent Awards
Outstanding Mentor Award. Colorado-Wyoming Chapter, American Fisheries Society (AFS), 2014
Best Article Nominee. Lake and Reservoir Management (Johnson and Martinez 2012), 2012
Award of Excellence. Study Sphere (Electronic Fish ID Flashcards), 2006
Best Professional Paper. Colorado-Wyoming Chapter, AFS, 2006
Provost’s N. Preston Davis Award for Instructional Innovation. Colorado State University, 2005
Certified Fisheries Professional. American Fisheries Society, 2002
Most Significant Paper. North American Journal of Fisheries Management (Johnson and Martinez 2000), 2001
Favorite Professor. College Student Council, Dept. of Fishery & Wildlife Biology, 2001

Recent Publications (Google Scholar Profile)

Christianson, K. R., and B. M. Johnson. 2020. Combined effects of early snowmelt and climate warming on mountain lake temperatures and fish energetics. Arctic, Antarctic and Alpine Research 52:130-145. doi.org/10.1080/15230430.2020.1741199

Christianson, K. R., B. M. Johnson, and M. B. Hooten. 2020. Compound effects of water clarity, inflow, wind and climate warming on mountain lake thermal regimes. Aquatic Sciences. doi.org/10.1007/s00027-019-0676-6

Christianson, K. R., B. M. Johnson, M. B. Hooten and J. J. Roberts. 2019. Estimating lake–climate responses from sparse data: an application to high elevation lakes. Limnology and Oceanography  doi.org/10.1002/lno.11121 

Hansen, A. G., J. S. Thompson, L. N. Hargis, D. Brauch, and B. M. Johnson. 2019. Predatory threat of introduced Yellow Perch in a salmonid dominated reservoir food web. North American Journal of Fisheries Management doi.org/10.1002/nafm.10257

Johnson, B. M., W. M. Pate, and D. B. Silver. 2018. Invasion success and status of the opossum shrimp, Mysis diluviana, in Wyoming, USA. Aquatic Invasions 13:409-420.  doi.org/10.3391/ai.2018.13.3.08   

Johnson, B. M., W. M. Pate, and A. G. Hansen. 2017. Energy density and dry matter content in fish: new observations and an evaluation of some empirical models. Transactions of the American Fisheries Society 146:1262-1278. doi.org/10.1080/00028487.2017.1360392

Johnson, C. F., B. M. Johnson, T. E. Neebling and J. C. Burckhardt. 2017. Walleye introduction eliminates predation refuge for adfluvial Cutthroat and Rainbow Trout. Transactions of the American Fisheries Society 146:252-267. doi.org/10.1080/00028487.2016.1254114

Wolff, B. A., B. M. Johnson and J. M. Lepak. 2017. Changes in sport fish mercury from food-web shifts suggest potential decoupling from atmospheric deposition in two Colorado reservoirs. Archives of Environmental Contamination and Toxicology doi: 10.1007/s00244-016-0353-x

Arlinghaus, R., J. Alos, B. Beardmore, K. Daedlow, M. Dorow, M. Fujitani, D. Huhn, W. Haider, L. M. Hunt, B. M. Johnson, F. Johnston, T. Kleforth, S. Matsumura, C. Monk, T. Pagel, J. R. Post, T. Rapp, C. Riepe, H. Ward, and C. Wolter. 2017. Understanding and managing freshwater recreational fisheries as complex adaptive social-ecological systems. Reviews in Fisheries Science and Aquaculture 25:1-41. dx.doi.org/10.1080/23308249.2016.1209160

Carim, K. J., K. R. Christianson, K. M. McKelvey, W. M. Pate, D. B. Silver, B. M. Johnson, B. T. Galloway, M. K. Young, and M. K Schwartz. 2016. Environmental DNA marker development with sparse biological information: A case study on Opossum Shrimp (Mysis diluviana). PLoS ONE 11(8): e0161664. doi:10.1371/journal.pone.0161664

Silver, D. B., B. M. Johnson, W. M. Pate, K. R. Christianson, J. Tipton, J. Sherwood, B. Smith, and Y. Hao. 2016. Effect of net size on estimates of abundance, size, age, and sex ratio of Mysis diluviana. Journal of Great Lakes Research 42:731-737. doi.org/10.1016/j.jglr.2016.02.012.

Wolf, J. M., B. M. Johnson, D. B. Silver, W. M. Pate, and K. R. Christianson. 2016. Freezing and fractionation: effects of preservation on carbon and nitrogen stable isotope values of some limnetic organisms. Rapid Communications in Mass Spectrometry 30:562-568.

Arlinghaus, R, K. Lorenzen, B. M. Johnson, S. J. Cooke, and I. G. Cowx. 2016. Management of freshwater fisheries: addressing habitat, people and fish. Pages 557-579 in J.F. Craig, editor. Freshwater fisheries ecology. Blackwell Science, UK.

Cooke, S. J., R. Arlinghaus, B. M. Johnson, and I. G. Cowx. 2016. Recreational fisheries in inland waters. Pages 449-465 in J. F. Craig, editor. Freshwater fisheries ecology. Blackwell Science, UK.

Johnson, B. M., J. Lepak and B. A. Wolff. 2015. Effects of prey assemblage on mercury bioaccumulation in a piscivorous sport fish. Science of the Total Environment 506-507: 330-337. doi.org/10.1016/j.scitotenv.2014.10.101

Pate, W., B. M. Johnson, J. Lepak, and D. Brauch. 2014. Managing for coexistence of kokanee and trophy Lake Trout in a montane reservoir. North American Journal of Fisheries Management 34:908-922. dx.doi.org/10.1080/02755947.2014.923072

Wolff, B.A., B.M. Johnson, and C.M. Landress. 2013. Classification of hatchery and wild fish using natural geochemical signatures in otoliths, fin rays, and scales of an endangered Catostomid. Canadian Journal of Fisheries and Aquatic Sciences 70:1775-1784.

Wolff, B.A., B.M. Johnson, A.R. Breton, P.J. Martinez, and D.L. Winkelman. 2012. Origins and movements of invasive piscivores determined from the strontium isotope (87Sr/86Sr) ratio of otoliths. Canadian Journal of Fisheries and Aquatic Sciences 69:724-739.

Lepak, J.M., M.B. Hooten, and B.M. Johnson. 2012. The influence of external subsidies on diet, growth and Hg concentrations of freshwater sport fish: implications for management and fish consumption advisories. Ecotoxicology 21:1878-1888.

Lepak, J.M., K-D. Kinzli, E.R. Fetherman, W.M. Pate, A.G. Hansen, E.I. Gardunio, C.N. Cathcart, W.L. Stacy, Z.E. Underwood, M.M. Brandt, C.A. Myrick, and B.M. Johnson. 2012. Manipulation of sport fish growth to reduce mercury bioaccumulation on a whole-system scale. Canadian Journal of Fisheries and Aquatic Sciences 69:122-135.

Johnson, B.M. and P.J. Martinez. 2012. Hydroclimate mediates effects of a keystone species in a coldwater reservoir. Lake and Reservoir Management 28:70-83. dx.doi.org/10.1080/07438141.2012.658492

Arlinghaus, R., S.J. Cooke and B.M. Johnson. 2012. Technical guidelines for responsible fisheries: recreational fisheries. Food and Agriculture Organization of the United Nations, Rome, Italy. http://www.fao.org/docrep/016/i2708e/i2708e00.htm 

graphical banner with fish colorations