Research

Annika Walters Lab

We are an applied aquatic ecology lab that conducts research in streams and rivers across Wyoming. Freshwater fishes are a threatened group in North America so many of our research projects are motivated by conservation concerns and have potential implications for management and restoration efforts. We use a variety of techniques and approaches including observational studies, field and laboratory experiments, and modeling. Our research addresses basic questions in population and community ecology and applied questions in conservation biology and fisheries management. A few major research themes in the lab are multiple stressors, fish movement patterns, and native fish conservation.

Multiple stressors

energy developmentAquatic ecosystems are currently subjected to multiple stressors, including habitat degradation, flow alteration, grazing, pollution, invasive species, and climate change. We are interested in understanding how these stressors, individually and interactively, influence aquatic ecosystems. One stressor we have been especially interested in is flow alteration as stream ecosystems experience frequent natural disturbance from droughts and floods and are undergoing considerable anthropogenic disturbance as a result of dam construction and water withdrawal. We are also starting to conduct research on energy development, a stressor particularly relevant to Wyoming. Energy development can affect fish due to shifts in habitat quality, sedimentation rates, water availability, and water quality.

Related Projects:

Impacts of natural gas development on the fisheries communities of the Wyoming Range

Ecological responses to multiple stressors in headwater streams of the Wyoming Range

Burbot in the Wind River Drainage

Related Publications:

Walters, A.W. 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

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

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. 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

Fish movement patternsburbot

Fish movement patterns provide insight into population connectivity, habitat requirements, and fish life-history. In addition, fish can be important vectors affecting the flux of energy and materials across ecosystem boundaries. We use a variety of approaches to examine fish movement including PIT-tagging and radio-telemetry to look at movement over the course of a season, stable isotope techniques to look at movement over the course of a lifetime, and genetic analyses to examine long-term movement patterns.

Related Projects:

Determining salmonid natal stream of origin and movement in the Upper NorthPlatte River Drainage, Wyoming using Sr isotopes in otoliths

Movement dynamics and survival of hatchery-reared Colorado River cutthroat trout post-stocking

Burbot in the Wind River Drainage

Related Publications:

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

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

Native fish conservationhornyhead chub

Freshwater taxa are declining at a rapid rate due to invasive species, development, dams, habitat degradation, and climate change. The challenge is to be proactive – recognizing threats and putting monitoring and management actions in place before a species has declined to unsustainable levels. We work closely with local managers to develop research projects for species of concern. Many of the projects are focused on evaluating threats and potential management options for a fish species of concern. In addition to species-based analyses we also conduct landscape-level analyses to identify priority management areas that can protect entire aquatic communities.

Related Projects:

Conservation and recovery of hornyhead chub

Movement dynamics and survival of hatchery-reared Colorado River cutthroat trout post-stocking

Related Publications:

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

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