Deemer, B.R., J.A. Harrison, 2019, Summer redox dynamics in a eutrophic reservoir and sensitivity to a summer’s end drawdown event: Ecosystems, v: 22, p. 1618-1632, https://doi.org/10.1007/s10021-019-00362-0.
Bridget R Deemer, Ph.D.
Biography
Broadly, I am interested in how human activities are affecting the way that energy and nutrients cycle through ecosystems. My research aims to better characterize how reservoirs can affect the transport and transformation of carbon (C), nitrogen (N), and other biologically relevant elements. My research also explores the potential role of management in affecting ecosystem function. Identifying reservoir management win-wins as well as trade-offs is critical as the quantity and quality of water becomes increasingly variable under a changing climate. Currently, I am working on a project to understand how conditions in Lake Powell (and the associated management of Glen Canyon Dam) are affecting ecosystem metabolism in the Colorado River.
Science and Products
Date published: January 18, 2017
Status: Active Uncovering the Base of the Food Web: Primary Production Dynamics in the Colorado River
Algae, phytoplankton, and rooted macrophytes represent the base of many aquatic food webs and are known as primary producers. Through photosynthesis, these organisms convert sunlight energy into chemical energy (i.e., carbon) that in turn fuels the growth of animals such as macroinvertebrates and fish. This project uses high frequency measurements of dissolved oxygen, which is a by-product of...
Year Published: 2021
Half of global methane emissions come from highly variable aquatic ecosystem sources
Atmospheric methane is a potent greenhouse gas that plays a major role in controlling the Earth’s climate. The causes of the renewed increase of methane concentration since 2007 are uncertain given the multiple sources and complex biogeochemistry. Here, we present a metadata analysis of methane fluxes from all major natural, impacted and human-...
Rosentreter, Judith A.; Borges, Alberto V.; Deemer, Bridget; Holgerson, Meredith A.; Liu, Shaoda; Song, Chunlin; Melack, John M.; Raymond, Peter A.; Duarte, Carlos M.; Allen, George H.; Olefeldt, David; Poulter, Benjamin; Batin, Tom I.; Eyre, Bradley D.Attribution: Southwest Biological Science Center, Ecosystems
Year Published: 2021
Drivers of methane flux differ between lakes and reservoirs, complicating global upscaling efforts
Methane is an important greenhouse gas with growing atmospheric concentrations. Freshwater lakes and reservoirs contribute substantially to atmospheric methane concentrations, but the magnitude of this contribution is poorly constrained. Uncertainty stems partially from whether the sites currently sampled represent the global population as well as...
Deemer, Bridget; Holgerson, Meredith A.Attribution: Southwest Biological Science Center, Ecosystems
Year Published: 2021
Greenhouse gas emissions from an arid-zone reservoir and their environmental policy significance: Results from existing global models and an exploratory dataset
Reservoirs in arid regions often provide critical water storage but little is known about their greenhouse gas (GHG) footprint. While there is growing appreciation of the role reservoirs play as GHG sources, there is a lack of understanding of GHG emission dynamics from reservoirs in arid regions and implications for environmental policy. Here we...
Waldo, Sarah; Deemer, Bridget; Bair, Lucas S.; Beaulieu, Jake J.Attribution: Southwest Biological Science Center, Ecosystems
Year Published: 2020
Changes in prey, turbidity, and competition reduce somatic growth and cause the collapse of a fish population
Somatic growth exerts strong control on patterns in the abundance of animal populations via effects on maturation, fecundity, and survival rates of juveniles and adults. In this paper, we quantify abiotic and biotic drivers of rainbow trout growth in the Colorado River, AZ, and the resulting impact on spatial and temporal variation in abundance....
Korman, Josh; Yard, Mike; Dzul, Maria C.; Yackulic, Charles; Dodrill, Michael; Deemer, Bridget; Kennedy, TheodoreAttribution: Southwest Biological Science Center, Ecosystems
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Year Published: 2020
Calcite precipitation in Lake Powell reduces alkalinity and total salt loading to the Lower Colorado River Basin
Reservoirs can retain and transform carbon, nitrogen, phosphorus, and silica, but less is known about their effects on other biogeochemically relevant solutes. The salinization of freshwater ecosystems is a growing concern in many regions, and the role of reservoirs in salinity transport is an important research frontier. Here, we examine how a...
Deemer, Bridget; Stets, Edward G.; Yackulic, Charles B.
Year Published: 2019
Methane emissions from artificial waterbodies dominate the carbon footprint of irrigation: A study of transitions in the food-energy-water-climate nexus (Spain, 1900-2014)
Irrigation in the Mediterranean region has been used for millennia and has greatly expanded with industrialization. Irrigation is critical for climate change adaptation, but it is also an important source of greenhouse gas emissions. This study analyzes the carbon (C) footprint of irrigation in Spain, covering the complete historical process of...
Aguilera, Eduardo; Vila-Traver, Jaime; Deemer, Bridget; Infante-Amate, Juan; Guzmán, Gloria I.; González de Molina, ManuelAttribution: Southwest Biological Science Center, Ecosystems
Pre-USGS Publications
Reed, D.C., B.R. Deemer, S. van Grinsven, and J.A. Harrison. 2017. Are elusive anaerobic pathways key methane sinks in eutrophic lakes and reservoirs? Biogeochemistry doi: 10.1007/s10533-017-0356-3
Hayes, N.M, B.R. Deemer, J.R. Corman, N.R. Razavi, and K.E. Strock. 2017. Key differences between lakes and reservoirs modify climate signals: A case for a new conceptual model. Limnology and Oceanography Letters doi: 10.1002/lol2.10036
Harrison, J.A., B.R. Deemer, M.K. Birchfield, and M.T. O’Malley. 2017. Reservoir water level drawdowns accelerate and amplify methane emission. Environmental Science & Technology doi: 10.1021/acs.est.6b03185
Deemer, B.R., J.A. Harrison, S. Li, J. Beaulieu, T. DelSontro, N. Barros, M.A. dos Santos, J.F.Bezerra-Neto, S.M. Powers, and J.A. Vonk. 2016. Greenhouse gas emissions from reservoir water surfaces: A new global synthesis. BioScience doi: 10.1093/biosci/biw117
Deemer, B.R., S.M. Henderson, and J.A. Harrison. 2015. Chemical mixing in the bottom boundary layer of a eutrophic reservoir: the effects of internal seiching on nitrogen dynamics. Limnology and Oceanography 60: 1642-1655.
Deemer, B.R., K.E. Goodwin, T.A. Lee, M.K. Birchfield, K. Dallavis, J. Emerson, D. Freeman, E. Henry, L. Wynn, and J.A. Harrison. 2012. Elevated nitrogen and phosphorus concentrations in urbanizing southwest Washington streams. Northwest Science 86: 237-247.
Henderson, S.M., and B.R. Deemer. 2012. Vertical propagation of lakewide internal waves. Geophysical Research Letters 39: doi:10.1029/2011GL050534.
Deemer, B.R., J.A. Harrison, and E.W. Whitling. 2011. Microbial dinitrogen and nitrous oxide production in a small eutrophic reservoir: an in situ approach to quantifying hypolimnetic process rates. Limnology and Oceanography 56: 1189-1199.