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
Lake Powell Research
Uncovering the Base of the Food Web: Primary Production Dynamics in the Colorado River
Rainbow trout growth data and growth covariate data from Glen Canyon, Colorado River, Arizona, 2012-2021
Limnology data from Lake Powell, desert southwest USA
Proximal and distal factors associated with the decline in secondary invertebrate prey production in the Colorado River, Glen Canyon, Arizona.
Gross primary production estimates and associated light, sediment, and water quality data from the Colorado River below Glen Canyon Dam
Modeled and measured greenhouse gas emissions from Lake Powell and bathymetric analysis of tributary littoral habitat at different water levels
Carbon, nitrogen, and phosphorus content of adult emergent Diptera before and after a fire-storm sequence in the Colorado River near Shinumo Creek, Grand Canyon, AZ
Calcium, magnesium and total dissolved solids data as well as modeled salinity and mass balance estimates for Lake Powell, 1952-2017
Over half a century record of limnology data from Lake Powell, desert southwest United States: From reservoir filling to present day (1964–2021)
Drought related changes in water quality surpass effects of experimental flows on trout growth downstream of Lake Powell reservoir
Peer review by and for non-native English speakers: Interacting across international limnology societies
Taking steps to address inequities in open-access publishing through an early career publication honor
Little bugs, big data, and Colorado River adaptive management: Preliminary findings from the ongoing bug flow experiment at Glen Canyon Dam
Experimental reductions in sub-daily flow fluctuations increased gross primary productivity for 425 river kilometers downstream
Early career researchers have questions about peer review—we asked the ASLO editors for answers
Spatiotemporal methane emission from global reservoirs
Half of global methane emissions come from highly variable aquatic ecosystem sources
Drivers of methane flux differ between lakes and reservoirs, complicating global upscaling efforts
Greenhouse gas emissions from an arid-zone reservoir and their environmental policy significance: Results from existing global models and an exploratory dataset
Changes in prey, turbidity, and competition reduce somatic growth and cause the collapse of a fish population
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.
Science and Products
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Lake Powell Research
Lake Powell is a large arid reservoir that represents about 70% of the water storage capacity for the Upper Colorado River Basin. It is the second largest reservoir in the United States by capacity (second only to Lake Mead). Lake Powell is an oligotrophic reservoir, which means that nutrient concentrations and algal production are generally low. This often results in very clear-water conditions...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... - Data
Rainbow trout growth data and growth covariate data from Glen Canyon, Colorado River, Arizona, 2012-2021
These data are the primary data used to model rainbow trout growth in Glen Canyon. Fish growth data were collected from nighttime boat electrofishing field campaigns conducted five to six times per year in April, July, September, and January, from April 2012 through November 2021 for a total of 9798 observations of mark-recapture-based growth. Sampling was conducted in a five km reach in the lowerLimnology data from Lake Powell, desert southwest USA
These data were compiled as part of a long-term (1964 - 2021) water quality monitoring program at Lake Powell. Objectives of our study were to release a consistent record of long-term water quality data. The 58-year limnology dataset captures some water quality parameters (temperature, salinity, major ions, total suspended solids) from reservoir filling to present day. It also contains a 38-year rProximal and distal factors associated with the decline in secondary invertebrate prey production in the Colorado River, Glen Canyon, Arizona.
Using a bioenergetic model, demographic data for the Rainbow Trout (Oncorhynchus mykiss) population were compiled and used to estimate total prey consumption in the Colorado River, Glen Canyon , AZ. Additionally, other data including invertebrate diet, drift, and benthic measurements were used to make generalized estimates of daily production rates for the most common benthic invertebrate taxa. ThGross primary production estimates and associated light, sediment, and water quality data from the Colorado River below Glen Canyon Dam
These data were compiled to model the effects of flow regime and bed grain size distributions on rates of gross primary production (GPP) in the Colorado River below Glen Canyon Dam, AZ, USA. The objectives of our study were to quantify daily and weekly scale effects of an experimental flow regime on GPP in the Colorado River. The experimental flow was conducted at Glen Canyon Dam from May-August iModeled and measured greenhouse gas emissions from Lake Powell and bathymetric analysis of tributary littoral habitat at different water levels
This data release contains model inputs used to estimate surface water greenhouse gas fluxes from two large arid reservoirs, Lake Powell and Lake Mead. The release also contains empirical, spatially explicit water quality and greenhouse gas data from a single field survey conducted in Lake Powell in July of 2017. Finally, this release contains surface area estimates of shallow (< 15m) tributary reCarbon, nitrogen, and phosphorus content of adult emergent Diptera before and after a fire-storm sequence in the Colorado River near Shinumo Creek, Grand Canyon, AZ
This dataset includes total phosphorus (TP), total nitrogen (TN), and total carbon (TC) concentrations as well as &amp;delta;15N and &amp;delta;13C composition, and overall C:N:P stoichiometry for adult emergent Diptera from the Colorado River, Grand Canyon, AZ. The samples were collected before and after a fire and subsequent storm occurred in the Shinumo Watershed, a tributary to the ColCalcium, magnesium and total dissolved solids data as well as modeled salinity and mass balance estimates for Lake Powell, 1952-2017
These data were compiled to quantify the role of Lake Powell in modulating salinity and reducing overall salt flux from the Upper Colorado River Basin downstream. In addition, these data were used to infer summertime calcite precipitation in Lake Powell (the major proposed sink for salt within the system). The Lake Powell Calcium Magnesium data contains summertime surface water calcium and magnesi - Multimedia
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Filter Total Items: 14
Over half a century record of limnology data from Lake Powell, desert southwest United States: From reservoir filling to present day (1964–2021)
Lake Powell is a large water storage reservoir in the arid southwestern United States. Here, we present a 58-yr limnology dataset that captures water quality parameters from reservoir filling to present day (temperature, salinity, major ions, total suspended solids), as well as a 38-yr record of Secchi depth, and a ~ 30-yr record of nutrients, phytoplankton, and zooplankton assemblages. The dataseDrought related changes in water quality surpass effects of experimental flows on trout growth downstream of Lake Powell reservoir
Flows released from reservoirs are often modified to mitigate the negative ecosystem effects of dams. We estimated the effects of two experimental flows, fall-timed floods and elimination of sub-daily variation in flows on weekends, on growth rates of rainbow trout (Oncorhynchus mykiss) in the Colorado River downstream from Glen Canyon Dam. Experimental flow effects were compared to effects of watPeer review by and for non-native English speakers: Interacting across international limnology societies
Scholarly peer review is critical to the scientific process, yet there are limited resources available for students, postdocs, and other early career researchers (ECRs) to learn how to perform effective and time-efficient review. The ASLO Raelyn Cole Editorial Fellows have developed several peer review training resources, including a webinar (https://www.youtube.com/watch?v=utntl1VGy5g), editorialTaking steps to address inequities in open-access publishing through an early career publication honor
Access to resources—whether human, financial, or social—is a key indicator of research output and, in turn, academic career progression. However, resources are not equally distributed among scientists and disparities often stem from external factors. This reality is particularly impactful for early career researchers (ECRs) who have limited control over the resources available to them to advance tLittle bugs, big data, and Colorado River adaptive management: Preliminary findings from the ongoing bug flow experiment at Glen Canyon Dam
The undammed Colorado River in Grand Canyon was characterized by spring snow-melt floods that sometimes exceeded 100,000 cubic feet per second (cfs). These were followed by occasional flash floods during summer monsoons, then by low flows from fall through early spring (Figure 1; Topping and others, 2003). This seasonally variable flow regime carried huge loads of sediment and was an important driExperimental reductions in sub-daily flow fluctuations increased gross primary productivity for 425 river kilometers downstream
Aquatic primary production is the foundation of many river food webs. Dams change the physical template of rivers, often driving food webs toward greater reliance on aquatic primary production. Nonetheless, the effects of regulated flow regimes on primary production are poorly understood. Load following is a common dam flow management strategy that involves sub-daily changes in water releases propEarly career researchers have questions about peer review—we asked the ASLO editors for answers
Peer review is the formal means by which the scientific community assesses the originality, reproducibility, validity, and quality of a research study (Bakker and Traniello 2019). As such, peer review assures nonexperts that they can trust a study's findings (Jamieson et al. 2019). Despite the critical importance of peer review, graduate students, postdocs, and other early career researchers (ECRsSpatiotemporal methane emission from global reservoirs
Inland aquatic systems, such as reservoirs, contribute substantially to global methane (CH4) emissions; yet are among the most uncertain components of the total CH4 budget. Reservoirs have received recent attention as they may generate high CH4 fluxes. Improved quantification of these CH4 fluxes, particularly their spatiotemporal distribution, is key to realistically incorporating them in CH4 modeHalf 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-made aquatic ecosystems. Our revised bottom-up globalDrivers 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 incomplete knowledge of which environmental variabGreenhouse 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 present initial GHG emission measurements from LakeChanges 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. Inferences are based on approximately 10,000 observaNon-USGS Publications**
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.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/s10533-017-0356-3Hayes, 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/lol2.10036Harrison, 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.6b03185Deemer, 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/biw117Deemer, 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.**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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