Theodore Kennedy, Ph.D.
I use food webs to describe ecosystem response to river regulation and biological invasions. I have been with USGS since 2004, providing science in support of the Glen Canyon Dam Adaptive Management Program.
Professional Experience:
11/04 - present. Research Ecologist, Grand Canyon Monitoring and Research Center, Southwest Biological Science Center, US Geological Survey, Flagstaff, AZ
1/04 - 11/04. Postdoctoral researcher, Arizona State University
1/03 - 1/04. Postdoctoral researcher, Grand Canyon Monitoring and Research Center, Southwest Biological Science Center, US Geological Survey, Flagstaff, AZ.
Education:
9/96 - 12/02. Ph.D. in Ecology, Dept. of Ecology, Evolution, and Behavior, University of Minnesota. Dissertation title: The causes and consequences of plant invasions
1/90 - 12/94. B.S. in Ecology, California Polytechnic State University at San Luis Obispo, cum laude.
Science and Products
Effects of three high-flow experiments on the Colorado River ecosystem downstream from Glen Canyon Dam, Arizona
Three experimental high-flow releases from Glen Canyon Dam, Arizona— Effects on the downstream Colorado River ecosystem
Proceedings of the Colorado River Basin Science and Resource Management Symposium, November 18-20, 2008, Scottsdale, Arizona
Basal Resources in Backwaters of the Colorado River Below Glen Canyon Dam-Effects of Discharge Regimes and Comparison with Mainstem Depositional Environments
Short-Term Effects of the 2008 High-Flow Experiment on Macroinvertebrates in Colorado River Below Glen Canyon Dam, Arizona
2008 High-Flow Experiment at Glen Canyon Dam Benefits Colorado River Resources in Grand Canyon National Park
Invasion and production of New Zealand mud snails in the Colorado River, Glen Canyon
The role of discharge variation in scaling of drainage area and food chain length in rivers
Comparisons of Water Quality and Biological Variables from Colorado River Shoreline Habitats in Grand Canyon, Arizona, under Steady and Fluctuating Discharges from Glen Canyon Dam
A Dreissena Risk Assessment for the Colorado River Ecosystem
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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Effects of three high-flow experiments on the Colorado River ecosystem downstream from Glen Canyon Dam, Arizona
Three high-flow experiments (HFEs) were conducted by the U.S. Department of the Interior at Glen Canyon Dam, Arizona, in March 1996, November 2004, and March 2008. These experiments, also known as artificial or controlled floods, were large-volume, scheduled releases of water from Glen Canyon Dam that were designed to mimic some aspects of pre-dam Colorado River seasonal flooding. The goal of thesAuthorsTheodore S. MelisThree experimental high-flow releases from Glen Canyon Dam, Arizona— Effects on the downstream Colorado River ecosystem
Three high-flow experiments (HFEs) were conducted by the U.S. Department of the Interior at Glen Canyon Dam, Arizona, in March 1996, November 2004, and March 2008. Also known as artificial or controlled floods, these scheduled releases of water above the dam's powerplant capacity were designed to mimic pre-dam seasonal flooding on the Colorado River. The goal of the HFEs was to determine whether hAuthorsTheodore S. Melis, Paul E. Grams, Theodore A. Kennedy, Barbara E. Ralston, Christopher T. Robinson, John C. Schmidt, Lara M. Schmit, Richard A. Valdez, Scott A. WrightProceedings of the Colorado River Basin Science and Resource Management Symposium, November 18-20, 2008, Scottsdale, Arizona
Since the 1980s, four major science and restoration programs have been developed for the Colorado River Basin to address primarily the conservation of native fish and other wildlife pursuant to the Endangered Species Act (ESA): (1) Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin (commonly called the Upper Colorado River Endangered Fish Recovery ProgramAuthorsTheodore S. Melis, John F. Hamill, Glenn E. Bennett, Lewis G. Coggins,, Paul E. Grams, Theodore A. Kennedy, Dennis M. Kubly, Barbara E. RalstonBasal Resources in Backwaters of the Colorado River Below Glen Canyon Dam-Effects of Discharge Regimes and Comparison with Mainstem Depositional Environments
Eight species of fish were native to the Colorado River before the closure of Glen Canyon Dam, but only four of these native species are currently present. A variety of factors are responsible for the loss of native fish species and the limited distribution and abundance of those that remain. These factors include cold and constant water temperatures, predation and competition with nonnative fishAuthorsKatherine E. Behn, Theodore A. Kennedy, Robert O. HallShort-Term Effects of the 2008 High-Flow Experiment on Macroinvertebrates in Colorado River Below Glen Canyon Dam, Arizona
Glen Canyon Dam has dramatically altered the physical environment (especially discharge regime, water temperatures, and sediment inputs) of the Colorado River. High-flow experiments (HFE) that mimic one aspect of the natural hydrograph (floods) were implemented in 1996, 2004, and 2008. The primary goal of these experiments was to increase the size and total area of sandbar habitats that provide boAuthorsEmma J. Rosi-Marshall, Theodore A. Kennedy, Dustin W. Kincaid, Wyatt F. Cross, Holly A.W. Kelly, Kathrine A. Behn, Tyler White, Robert O. Hall, Colden V. Baxter2008 High-Flow Experiment at Glen Canyon Dam Benefits Colorado River Resources in Grand Canyon National Park
On March 5, 2008, the Department of the Interior began a 60-hour high-flow experiment at Glen Canyon Dam, Arizona, to determine if water releases designed to mimic natural seasonal flooding could be used to improve downstream resources in Glen Canyon National Recreation Area and Grand Canyon National Park. U.S. Geological Survey (USGS) scientists and their cooperators undertook a wide range of phyAuthorsTheodore S. Melis, David J. Topping, Paul E. Grams, David M. Rubin, Scott A. Wright, Amy E. Draut, Joseph E. Hazel, Barbara E. Ralston, Theodore A. Kennedy, Emma Rosi-Marshall, Josh Korman, Kara D. Hilwig, Lara M. SchmitInvasion and production of New Zealand mud snails in the Colorado River, Glen Canyon
Species invasions are often associated with large-scale human alteration of ecosystems. One classic example is the increasing dominance of non-native taxa below and above dams on large rivers. These dams substantially alter the physical template of river ecosystems, and exotic taxa often proliferate with potentially large impacts on coexisting taxa and ecosystem processes. Here we document the invAuthorsWyatt F. Cross, E.J. Rosi-Marshall, Katherine E. Behn, Theodore A. Kennedy, Robert O Jr. Hall, A. Elizabeth Fuller, C. V. BaxterThe role of discharge variation in scaling of drainage area and food chain length in rivers
Food chain length (FCL) is a fundamental component of food web structure. Studies in a variety of ecosystems suggest that FCL is determined by energy supply, environmental stability, and/or ecosystem size, but the nature of the relationship between environmental stability and FCL, and the mechanism linking ecosystem size to FCL, remain unclear. Here we show that FCL increases with drainage area anAuthorsJohn L. Sabo, Jacques C. Finlay, Theodore A. Kennedy, David M. PostComparisons of Water Quality and Biological Variables from Colorado River Shoreline Habitats in Grand Canyon, Arizona, under Steady and Fluctuating Discharges from Glen Canyon Dam
Glen Canyon Dam operations are known to affect mainstem Colorado River temperature and shoreline habitats for native fish. Options for ameliorating the impacts that operations have on young native fish include changing release volumes and/or changing the daily range of releases. Long-term alterations of operations that may produce a measurable biological response can be costly, particularly if theAuthorsBarbara E. Ralston, Matthew V. Lauretta, Theodore A. KennedyA Dreissena Risk Assessment for the Colorado River Ecosystem
Executive Summary Nonnative zebra and quagga mussels (Dreissena polymorpha and Dreissena bugensis, respectively; see photo above) were accidentally introduced to the Great Lakes in the 1980s and subsequently spread to watersheds of the Eastern United States (Strayer and others, 1999). The introduction of Dreissena mussels has been economically costly and has had large and far-reaching ecologicaAuthorsTheodore A. KennedyNon-USGS Publications**
Kennedy, T.A., 1998, Patterns of an invasion by Argentine ants (Linepithema humile) in a riparian corridor and its effects on ant diversity: The American Midland Naturalist, v. 140, p. 343-350.Naeem, S., Knops, J.M., Tilman, D., Howe, K.M., Kennedy, T. and Gale, S., 2000, Plant diversity increases resistance to invasion in the absence of covarying extrinsic factors: Oikos, v. 91, p. 97-108, DOI: 10.1034/j.1600-0706.2000.910108.x.Raffaelli, D., Van der Putten, W.H., Persson, L., Wardle, D.A., Petchey, O.L., Koricheva, J., Van Der Heijden, M., Mikola, J. and Kennedy, T., 2002, Multi-trophic dynamics and ecosystem processes, In Loreau, M., Naeem, S., and Inchausti, P., eds., Biodiversity and ecosystem functioning: synthesis and perspectives: Oxford, Oxford University Press, p.147-154.Levine, J.M., Kennedy, T., and Naeem, S., 2002, Neighborhood scale effects of species diversity on biological invasions and their relationship to community patterns, In Loreau, M., Naeem, S., and Inchausti, P., eds., Biodiversity and ecosystem functioning: synthesis and perspectives: Oxford, Oxford University Press, p.114-124.Kennedy, T.A., Naeem, S., Howe, K.M., Knops, J.M., Tilman, D., and Reich, P., 2002, Biodiversity as a barrier to ecological invasion. Nature, v.417, p.636. doi:10.1038/nature00776.Kennedy, T.A., and Hobbie, S.E., 2004, Saltcedar (Tamarix ramosissima) invasion alters organic matter dynamics in a desert stream. Freshwater Biology, v. 49, p. 65-76. doi: 10.1046/j.1365-2426.2003.01166.x.Kennedy, T.A., Finlay, J.C., and Hobbie, S.E., 2005, Eradication of invasive Tamarix ramosissima along a desert stream increases native fish density: Ecological Applications, v. 15, p. 2072-2083.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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