General research interests: Research in the Fish Ecology Lab focuses on the conservation of aquatic systems in the western and central U.S. Current and past projects can be classified into three general areas: 1) effects of global change on diversity-ecosystem function relationships in streams, 2) evaluation of patterns and processes regulating species diversity and habitat associations of fishes in streams and reservoirs, and 3) dynamics of non-coevolved fish assemblages.
Post Doctoral Associates and Graduate Students
My research focuses on the impacts of riverscape fragmentation on the distribution of imperiled Great Plains fishes. Specifically, I’m working with (1) the declining status of pelagic-spawning cyprinids as related to the fragmentation of large Great Plains rivers; (2) effects of barriers to dispersion on community composition within prairie stream fish communities; and (3) developing predictive models for the movement of fishes within dendritic ecological networks. Josh's webpage
My dissertation research focuses on evaluating how fish movement and riverscape dynamics affect prairie stream community structure and ecosystem properties. Current objectives are to evaluate (1) density-dependent interactions of prairie stream fish (2) priority effects and dominance hierarchies (if they occur, and how important are they) and 3) the influence of the environment on the fish community as well as the influence the fish have on their environment. My general interests include anthropogenic disturbances, metacommunity ecology, and conservation biology. Erika's webpage
Species in the metacommunity differ in their dispersal aptitude, and these differences may be related to certain traits possessed by the species, such as life-history strategy. Native and nonnative fishes in the upper Gila River Basin of southwestern New Mexico show highly-divergent life-history strategies, thus potentially exhibiting different degrees of dispersal ability. These differences in dispersal ability could translate into variation in metacommunity structure across a longitudinal gradient of the upper Gila, and may be affecting species persistence across multiple spatial and temporal scales. Under a combined framework of metacommunity and life-history theory, the primary goals of my PhD research will be to quantify differences in dispersal ability among fishes exhibiting different life-history strategies in the upper Gila River, and to determine the influence of these dispersal differences on metacommunity structure and function.
The objectives of my dissertation research are to quantify niche dynamics of Great Plains stream fishes and gain a mechanistic understanding of species–habitat relationships. First, I will examine niche shifts of populations that occur in different drainage basins and use phylogenetic relationships among species to examine how niche dimensions evolve. Understanding niche dynamics at both ecological and evolutionary time scales is important in predicting how species distributions’ will respond to climate change and habitat alteration. Secondly, I will carry out a series of experiments to quantify how several prominent environmental gradients influence the physiological performance of individuals (e.g., growth and body condition) and mediate interspecific interactions. Understanding which abiotic variables are causally linked to survivorship and population dynamics is necessary for producing niche and distribution models that can be extrapolated in time and space.
My research will attempt to quantify the movement of native species in the San Juan River basin of Colorado, New Mexico, and Utah. Fishes studied include, but are not limited to, bluehead sucker, flannelmouth sucker, and roundtail chub. Currently, my approach will utilize two primary tools: 1) GIS to identify species distribution among habitats in the San Juan basin based on historical and contemporary fish data and 2) PIT tag studies to track movement rates of native fishes within and between habitats.
My postdoctoral research is associated with the SCALER project. The overarching question is: How can small-scale ecological experiments be applied to understand operation of entire ecological systems? Specifically this project will ask how can we use cm- and reach-scale process measurements and consumer manipulation experiments to predict ecosystem characteristics of stream networks, and how do patterns of scaling compare across an array of North American biomes? The SCALER experiment: a continental scale experiment encompassing five biomes, each of which will have six sites with measurements nested at two scales (microhabitat, reach), linked to watershed models will answer these questions.
The flathead catfish (Pylodictis olivaris) is now common in the Gila River and this voracious predator is known to consume native fishes. Understanding flathead catfish movement patterns in this desert stream can inform the conservation of native species such as the federally endangered Spikedace (Meda fulgida) and Loach minnow (Tiaroga cobitis). My objective is to characterize seasonal movement of flathead catfish throughout the upper Gila River basin. I will evaluate movement at different temporal scales (hourly, daily and seasonal) and relate movement to body size. This will be done by implanting radio transmitters into fish and tracking individuals throughout the year.
David Hoeinghaus, Post doc 2007 – 2009. Life-history traits predict conservation status of fishes in Great Plains. Current position: Assistant Professor, University of North Texas
Tyler Pilger, MS 2009 (Trophic relations in the upper Gila River, New Mexico). Current Positio: PhD Student, University of New Mexico
Michelle Evans-White, Post doc 2006-2007. Forecasting ecological change in aquatic systems in the Great Plains. Current position: Assistant Professor, University of Arkansas
Katie Bertrand, PhD 2007. Interactive effects of disturbance regime and species composition on ecosystem function of prairie streams. Current position: Assistant Professor, South Dakota State University
Darren Thornbrugh, MS 2008. Fish assemblage structure in adventitious streams. Current position: PhD student, Michigan State University.
Nate Franssen, MS 2007. Trophic relations of the Colorado pikeminnow (Ptychocheilus lucius) in the San Juan River, New Mexico and Utah. Current position: Postdoctoral Research Associate, University of New Mexico.
Tim Strakosh, PhD 2006. The effects of water willow establishment on littoral community composition: with focus on age-0 centrarchids in Kansas reservoirs. Current position: US Fish and Wildlife Service, Green Bay Fish and Wildlife Conservation Office.
Layne Knight, MS 2004. Effects of largemouth bass predation on native stream minnows: implications for conservation of the endangered Topeka shiner. Current position: Biologist, Kansas Department of Health and Environment.
Jeff Falke, MS 2004. Upstream effects of large reservoirs on native stream fishes. Current position: Assistant Leader - Fisheries, U.S. Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit
The experimental stream facility on Konza Prairie Biological Station provide a venue to manipulate stream biodiversity, nutrients, substrates, and many other aspects of streams. These manipulations can be used to test mechanistic hypotheses of main drivers of stream community structure and ecosystem function.
Quillback (Carpiodes cyprinus) Kansas River, KS