Annika has been the Assistant Unit Leader for Fisheries at the WY coop unit since 2011. She is an applied aquatic ecologist with research interests in population and community ecology, fisheries, and conservation biology. Annika has an undergraduate degree in Ecology and Evolutionary Biology from Princeton University and a MS and PhD in Ecology and Evolutionary Biology from Yale University. She has conducted research on a variety of topics including low flow disturbance, nutrient loading by anadromous alewife, the effects of climate change and water diversion on salmon, and phenology of phytoplankton communities. She and her students are currently working across the state of Wyoming addressing topics related to oil and natural gas development, multiple stressors, flow alteration, fish movement, and native fish conservation. Much of her research focuses on improving our understanding of how anthropogenic disturbance affects aquatic communities. She works closely with agency cooperators across the state to address questions that can help inform the management of fishes and aquatic ecosystems.
Professional Preparation and Appointments
Education
Ph.D., Ecology and Evolutionary Biology, Yale University, New Haven, CT
Thesis: Community and ecosystem level impacts of disturbance in streams
M.S., Yale University, New Haven, CT
B.A., Princeton University, Princeton, NJ
Professional appointments
| 2018 – present2011 – 2018 | Associate Professor, Department of Zoology and Physiology, University of WyomingAssistant Professor, Department of Zoology and Physiology, University of Wyoming |
| 2011 – present | Assistant Unit Leader – Fisheries, USGS Wyoming Cooperative Fish and Wildlife Unit |
| 2011 | NSF Bioinformatics Postdoctoral Fellow, School of Aquatic and Fishery Sciences, University of Washington, Seattle |
| 2009-2010 | NRC Postdoctoral Research Associate, NOAA Northwest Fisheries Science Center, Seattle, Washington |
Publications
Baldock, J.R., R. Al-Chokhachy, M.R. Campbell, and A.W. Walters. 2023. Timing of reproduction underlies fitness trade-offs for a salmonid fish. Oikos e10184 https://doi.org/10.1111/oik.10184 View PDF
Messager, M.L., J.D. Olden, J. Tonkin, R. Stubbington, J.S. Rogosch, M.H. Busch, C.J. Little, A.W. Walters, C.L. Atkinson, M. Shanafield, S. Yu, K. Boersma, D. Lytle, R.H. Walker, R.M. Burrows, T. Datry. 2023. A metasystem approach to designing environmental flows. Bioscience. biad067 https://doi.org/10.1093/biosci/biad067 View PDF
Ruthven, J.S., and J. Leonard, and A.W. Walters. 2023. Assessment of invasive Brook Stickleback Culaea inconstans occupancy, habitat drivers, and overlap with native fishes in the North Platte River drainage, Wyoming. Hydrobiologia doi.org/10.1007/s10750-023-05262-y View PDF
Combrink, L.L., W.C. Rosenthal, L.J. Boyle, J.A. Rick, A.C. Krist, A.W. Walters, and C.E. Wagner. 2023. Parallel shifts in trout feeding morphology suggest rapid adaptation to alpine lake environments. Evolution 77(7): 1522-1538. https://doi.org/10.1093/evolut/qpad059 View PDF
Newkirk, B.M., E.R. Larson, A.D. Walker, and A.W. Walters. 2023. Winners and losers over a half century of change in crayfish communities of Wyoming, U.S.A. Freshwater Science 42(2): 146-160. https://doi.org/10.1086/725318 View PDF
Ruthven, J.S., and A.W. Walters. 2023. Invasive Brook Stickleback Culaea inconstans has limited effects on the trophic ecology of native fishes in Wyoming, USA. Food Webs 35 e00275. https://doi.org/10.1016/j.fooweb.2023.e00275 View PDF
Baldock, J.R., R. Al-Chokhachy, T.E. Walsworth, and A. Walters. 2023 Redd superimposition mediates the accuracy, precision, and significance of redd counts for cutthroat trout. Canadian Journal of Fisheries and Aquatic Sciences. https://doi.org/10.1139/cjfas-2022-0267 View PDF
Datry, T., A. Truchy, J.D. Olden, M.H. Busch, R. Stubbington, W.K. Dodds, S. Zipper, S. Yu, M.L. Messager, J. Tonkin, K. Kaiser, J. Hammond, E.K. Moody, R.M. Burrows, R. Sarremejane, A. DelVecchia, M.L. Fork, C.J. Little, R.H. Walker, A.W. Walters, D. Allen. 2023. Causes, responses, and implications of anthropogenic versus natural flow intermittence in river networks. BioScience 73(1): 9-22. https://doi.org/10.1093/biosci/biac098 View PDF
Fennell, J.M., W.C. Rosenthal, C.E. Wagner, J.C. Burckhardt, and A.W. Walters. 2023. Temporal segregation in spawning between native Yellowstone cutthroat trout and introduced rainbow trout. Ecology of Freshwater Fish 32(1): 94-106. http://doi.org/10.1111/eff.12672 View PDF
Wenger, S.J., E.S. Stowe, K.B. Gido, M.C. Freeman, Y. Kanno, N.R. Franssen, J.D. Olden, N.L. Poff, A.W. Walters, P.M. Bumpers, M.C. Mims, M.B. Hooten, and L. Lu. 2022. Simple statistical models can be useful for testing hypotheses with population time series data. Ecology and Evolution 12(9): e9339 http://dx.doi.org/10.1002/ece3.9339 View PDF
Rosenthal, W.R., J.M. Fennell, E.G. Mandeville, J.C. Burckhardt, A.W. Walters, and C.E. Wagner. 2022. Effects of reproductive fitness in a hybridizing trout population. Molecular Ecology 31(16): 4224-4241. http://doi.org/10.1111/mec.16578 View PDF
Barrile, G. M., Chalfoun, A. D, Estes-Zumpf, W., and Walters, A. W. 2022. Wildfire influences individual growth and breeding dispersal, but not survival and recruitment in a montane amphibian. Ecosphere, 13(8), e4212. https://doi.org/10.1002/ecs2.4212 View PDF
Freeman, M.C., K.R. Bestgen, D. Carlisle, E.A. Frimpong, N.R. Franssen, K.B. Gido, E. Irwin, Y. Kanno, C. Luce, A.K. McKay, M.C. Mims, J.D. Olden, N. L. Poff, D.L. Propst, L. Rack. A.H. Roy, E.S. Stowe, A.W. Walters, and S.J., Wenger. 2022. Towards improved understanding of streamflow effects on freshwater fisheries. Fisheries 47(7): 290-298. https://doi.org/10.1002/fsh.10731 View PDF
Barrile, G. M., Walters, A. W., and Chalfoun, A. D. 2022. Stage-specific environmental correlates of reproductive success in Boreal Toads (Anaxyrus boreas boreas). Journal of Herpetology, 56(1), 34–44. https://doi.org/10.1670/21-023 View PDF
Booher, E. and A.W. Walters. 2022. Identifying translocation sites for a climate relict population of Finescale Dace (Chrosomus neogaeus). Transactions of the American Fisheries Society 151(2): 245-259 10.1002/tafs.10348 View PDF
M.A. Kirk, B.M. Maitland, B.T. Hickerson, A.W. Walters, and F.J. Rahel. 2022. Climatic drivers and ecological impacts of a rapid range expansion by non-native smallmouth bass in a Wyoming river. Biological Invasions 24: 1311-1326. https://doi.org/10.1007/s10530-021-02724-z View PDF
Alford, S.A. and A.W. Walters. 2022. Rapid post-disturbance colonisation contributes to native fish resilience. Ecology of Freshwater Fish doi.org/10.1111/eff.12634 View PDF
Barrile, G.M., A. D. Chalfoun, and A.W. Walters. 2021. Livestock grazing, climatic variation, and breeding phenology jointly shape disease dynamics and survival in a wild amphibian. Biological Conservation 261: 109247. doi.org/10.1016/j.biocon.2021.109247 View PDF
LeCheminant A.G., G.M. Barrile, S.E. Albeke, A.W. Walters. 2021. Movement dynamics and survival of stocked Colorado River cutthroat trout Oncohynchus clarkii pleuriticus. Transactions of the American Fisheries Society doi.org/10.1002/tafs.10322 View PDF
Barrile, G.M., A.W. Walters, M. Webster, and A.D. Chalfoun. 2021. Informed breeding dispersal following stochastic changes to patch quality in a pond-breeding amphibian. Journal of Animal Ecology doi.org/10.1111/1365-2656.13503 View PDF
B.J. Nordberg, E.G. Mandeville, A.W. Walters, J.C. Burckhardt, and C.E. Wagner. 2021. Historical data illustrate the complex effects of stocking in Cutthroat Trout populations. North American Journal of Fisheries Management doi.org/10.1002/nafm.10593 View PDF
Booher, E. and A.W. Walters. 2021. Biotic and abiotic determinants of finescale dace distribution at the southern edge of their range. Diversity and Distributions 27: 696-709. doi.org/10.1111/ddi.13227 View PDF
Barrile, G.M., A.D. Chalfoun, A.W. Walters. 2021. Infection status as the basis for habitat choices in a wild amphibian. American Naturalist 197: 128-137. doi.org/10.1086/711927 View PDF
Walker, R.H., C.E. Girard, S.L. Alford, and A.W. Walters. 2020. Anthropogenic land-use change intensifies the effect of low flow on stream fishes. Journal of Applied Ecology 57: 149-159. doi.org/10.1111/1365-2664.13517 View PDF
Ciepiela, L.R., and A.W. Walters. 2019. Life-history variation of two inland salmonids revealed through otolith microchemistry analysis. Canadian Journal of Fisheries and Aquatic Sciences 76(11):1971-1981 doi.org/10.1139/cjfas-2018-0087 View PDF
Hickerson, B.T., B.M. Maitland, and A.W. Walters. 2019. Effects of multiple nonnative predatory fish on an imperiled cyprinid, Hornyhead Chub (Nocomis biguttatus). Transactions of the American Fisheries Society 148: 1132-1145, doi.org/10.1002/tafs.10203 View PDF
Walker, R.H. and A.W. Walters. 2019. A mechanistic understanding of ecological responses to anthropogenic surface disturbance in headwater streams. Ecosphere 10(10):e02907. doi.org/10.1002/ecs2.2907. View PDF
Mandeville, E.G., A.W. Walters, B.J. Nordberg, K.Higgins, J.C. Burkhardt, and C.E. Wagner. 2019. Genomic outcomes of trout hybridization vary with stocking history. Molecular Ecology 28: 3738-3755 doi.org/10.1111/mec.15175 View PDF
Mandeville, C.P., F. Rahel, L.S. Patterson, and A.W. Walters. 2019. Applying threshold analysis to identify stream fish thermal guilds for water temperature regulation. Transactions of the American Fisheries Society 148(4): 739-754. doi.org/10.1002/tafs.10169 View PDF
Ciepiela, L.R., and A.W. Walters. 2019. Quantifying ⁸⁷Sr/⁸⁶Sr temporal stability and spatial heterogeneity for use in tracking fish movement. Canadian Journal of Fisheries and Aquatic Sciences. doi.org/10.1139/cjfas-2018-0124 View PDF
Walters, A.W., C.E. Girard, R.H. Walker*, A. Farag, and D. Alvarez. 2019. Multiple approaches to surface water quality assessment provide insight for small streams experiencing oil and natural gas development. Integrated Environmental Assessment and Management 9999:1-13. doi.org/10.1002/ieam.4118 View PDF
Hickerson, B.T. and A.W. Walters. 2019. Evaluation of potential translocation sites for an imperiled cyprinid, Hornyhead Chub (Nocomis biguttatus). North American Journal of Fisheries Management 39:205-218. doi.org/10.1002/nafm.10261 View PDF
Walters, A.W., C. Peterson, F. Rahel. 2018. The interaction of exposure and sensitivity determines fish species vulnerability to warming stream temperatures. Biology Letters 14:20180342. org/10.1098/rsbl.2018.0342. View PDF
Girard, C.E. and A.W. Walters. 2018. Evaluating relationships between fishes and habitat in streams affected by oil and natural gas development. Fisheries Management and Ecology 25: 366-379. doi.org/10.1111/fme.12303 View PDF
Hooley-Underwood, Z., E. Mandeville, P. Gerritty, J. Deromedi, K. Johnson, and A.W. Walters. 2018. Combining genetic, isotopic, and field data to better describe movement and entrainment of burbot (Lota lota). Transactions of the American Fisheries Society 147: 606-620. doi/10.1002/tafs.10062. View PDF
Stewart, D.R., Z.E. Underwood*, F.J. Rahel, and A.W. Walters. 2018. The effectiveness of surrogate taxa to conserve freshwater biodiversity. Conservation Biology 32: 183-194. doi/10.1111/cobi.12967. View PDF
Walters, A.W., Mandeville, W.C. Saunders, P. Gerrity, J. Skorupski, Z. Underwood*, E. Gardunio. 2017. Comparison of burbot population dynamics across adjacent native and invaded ranges. Aquatic Invasions 12: 251-262 doi.org/10.3391/ai.2017.12.2.12. View PDF
Gsell, A.S., Scharfenberger, U., D. Özkundakci, A.W. Walters, L. Hansson, P. Nõges, P.C. Reid, D.E. Schindler, E. van Donk, V. Dakos, R. Adrian. 2016. Early-warning signals foreshadow regime shifts in natural aquatic ecosystems. PNAS doi: 10.1073/pnas.1608242113. View PDF
Walters, A.W. 2016. The importance of context dependency for understanding the effects of low flow events on fish. Freshwater Science 35:216-228 doi:10.1086/683831. View PDF
Stewart, D.R., A,W. Walters, and F. Rahel. 2016. Factors influencing native and nonnative Great Plains fishes in Wyoming. Diversity and Distributions 22:225-238 doi: 10.1111/ddi.12383. View PDF
Underwood, Z.*, E. Mandeville, and A.W. Walters. 2016. Population connectivity and genetic clustering of burbot populations in the Wind River Basin, Wyoming. Hydrobiologia 765:329-342 doi: 10.1007/s10750-015-2422-y. View PDF
Senecal, A. C., A. W. Walters, and W. A. Hubert. 2015. Historical data reveal fish assemblage shifts in an unregulated prairie river. Ecosphere 6(12):287. http://dx.doi.org/10.1890/ES14-00361.1. View PDF
Entrekin, S., K.O. Maloney, K. Kapo, A.W. Walters, M. Evans-White, K. Klemov. 2015. Stream vulnerability to widespread and emergent stressors: a focus on unconventional oil and gas. PLoS ONE 10(9): e0137416. doi:10.1371/journal.pone.0137416. View PDF
Godwin, B.L., S.E. Albeke, H.L. Bergman, A. Walters, and M. Ben-David. 2015. Density of river otters (Lontra canadensis) in relation to energy development in the Green River Basin, Wyoming. Science of the Total Environment 532:780-790. View PDF
Pantel, J., D. Pendleton, A. Walters, and L. Rogers. 2014. Linking environmental variability to population and community dynamics. p. 119-131. In P.F. Kemp [ed.], Eco-DAS IX Symposium Proceedings. ASLO. [doi: 10.4319/ecodas.2014.978-0-9845591-3-8.119]. View PDF
Walters, A.W., K.K. Bartz, and M.M. McClure. 2013. Interactive effects of water diversion and climate change for juvenile Chinook salmon in the Lemhi River. Conservation Biology 27:1179-1189. View PDF
Walters, A.W., M.A.G. Sagrario, and D.E. Schindler. 2013. Species and community level responses combine to drive phenology of lake phytoplankton. Ecology 94:2188-2194. View PDF
Walters, A.W., T. Copeland, and D.A. Venditti. 2013. The density dilemma: limitations on juvenile production in threatened salmon populations. Ecology of Freshwater Fish 22:508-519. View PDF
Walters, A.W., D. M. Holzer, J. R. Faulkner, C. D. Warren, P. D. Murphy, and M.M. McClure. 2012. Quantifying cumulative entrainment effects for Chinook salmon in a heavily irrigated watershed. Transactions of the American Fisheries Society 141:1180-1190. View PDF
Walters, A.W. 2011. Resistance of aquatic insects to a low flow disturbance: exploring a trait-based approach. Journal of the North American Benthological Society 30: 346-356. View PDF
Walters, A.W. and D.M. Post. 2011. How low can you go? Response of aquatic insect communities to low flow disturbance. Ecological Applications 21:163-174. View PDF
West, D., A.W. Walters, S. Gephart, D.M. Post. 2010. Nutrient loading by anadromous alewives: contemporary patterns and predictions for restoration efforts. Canadian Journal of Fisheries and Aquatic Sciences 67: 1211-1220. View PDF
Walters, A.W., R.T. Barnes, and D.M. Post. 2009. Anadromous alewife contribute marine-derived nutrients to coastal stream food webs. Canadian Journal of Fisheries and Aquatic Sciences 66:439-448. View PDF
Post D.M. and A.W. Walters. 2009. Nutrient excretion rates of anadromous alewives during their spawning migration. Transactions of the American Fisheries Society 138: 264-268. View PDF
Walters, A.W. and D.M. Post. 2008. An experimental disturbance alters fish size structure, but not food chain length in streams. Ecology 89: 3261-3267. View PDF
Projects
- Community assembly in alpine lakes of the Wind River Range
- Evaluating the role of spring-fed streams to Snake River cutthroat trout population dynamics
- Evaluation of potential translocation sites for finescale dace in Eastern Wyoming