Brian Bergamaschi
Dr. Brian Bergamaschi is a research biogeochemist with the USGS California Water Science Center and adjunct Faculty at California State University Sacramento.
Brian received a Ph.D. in Chemical Oceanography from the University of Washington, in Seattle, WA, where he specialized in analyzing the sources and fates of natural organic material in the environment. His main interests are in understanding processes of carbon and nutrient cycling in aquatic environments and related biogeochemical processes. His particular interest is developing methods to quantify interactions between physical and biogeochemical processes. His research ranges in scale from light-mediated molecular transformations, to tidally driven wetland exchange, to effects of changing continental-scale nutrient fluxes on coastal carbon processes. His current projects largely focus on aquatic biogeochemical processes, aquatic habitat quality and carbon cycling in aquatic systems.
Science and Products
The river as a chemostat: fresh perspectives on dissolved organic matter flowing down the river continuum
Mississippi River nitrate loads from high frequency sensor measurements and regression-based load estimation
Baseline and projected future carbon storage and greenhouse-gas fluxes in ecosystems of the eastern United States
Concurrent photolytic degradation of aqueous methylmercury and dissolved organic matter
Optical sensors for water quality
DOM composition in an agricultural watershed: assessing patterns and variability in the context of spatial scales
Groundwater contributions of flow, nitrate, and dissolved organic carbon to the lower San Joaquin River, California, 2006-08
The role of irrigation runoff and winter rainfall on dissolved organic carbon loads in an agricultural watershed
Optical techniques for the determination of nitrate in environmental waters: Guidelines for instrument selection, operation, deployment, maintenance, quality assurance, and data reporting
Sources and characteristics of organic matter in the Clackamas River, Oregon, related to the formation of disinfection by-products in treated drinking water
Mercury dynamics in a San Francisco estuary tidal wetland: assessing dynamics using in situ measurements
Baseline and projected future carbon storage and greenhouse-gas fluxes in ecosystems of the Western United States
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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The river as a chemostat: fresh perspectives on dissolved organic matter flowing down the river continuum
A better understanding is needed of how hydrological and biogeochemical processes control dissolved organic carbon (DOC) concentrations and dissolved organic matter (DOM) composition from headwaters downstream to large rivers. We examined a large DOM dataset from the National Water Information System of the US Geological Survey, which represents approximately 100 000 measurements of DOC concentratAuthorsIrena F. Creed, Diane M. McKnight, Brian Pellerin, Mark B. Green, Brian A. Bergamaschi, George R. Aiken, Douglas A. Burns, Stuart E G Findlay, James B. Shanley, Robert G. Striegl, Brent T. Aulenbach, David W. Clow, Hjalmar Laudon, Brian L. McGlynn, Kevin J. McGuire, Richard A. Smith, Sarah M. StackpooleMississippi River nitrate loads from high frequency sensor measurements and regression-based load estimation
Accurately quantifying nitrate (NO3–) loading from the Mississippi River is important for predicting summer hypoxia in the Gulf of Mexico and targeting nutrient reduction within the basin. Loads have historically been modeled with regression-based techniques, but recent advances with high frequency NO3– sensors allowed us to evaluate model performance relative to measured loads in the lower MissisAuthorsBrian A. Pellerin, Brian A. Bergamaschi, Robert J. Gilliom, Charles G. Crawford, John Franco Saraceno, C. Paul Frederick, Bryan D. Downing, Jennifer C. MurphyBaseline and projected future carbon storage and greenhouse-gas fluxes in ecosystems of the eastern United States
This assessment was conducted to fulfill the requirements of section 712 of the Energy Independence and Security Act of 2007 and to conduct a comprehensive national assessment of storage and flux (flow) of carbon and the fluxes of other greenhouse gases in ecosystems of the Eastern United States. These carbon and greenhouse gas variables were examined for major terrestrial ecosystems (forests, graConcurrent photolytic degradation of aqueous methylmercury and dissolved organic matter
Monomethyl mercury (MeHg) is a potent neurotoxin that threatens ecosystem viability and human health. In aquatic systems, the photolytic degradation of MeHg (photodemethylation) is an important component of the MeHg cycle. Dissolved organic matter (DOM) is also affected by exposure to solar radiation (light exposure) leading to changes in DOM composition that can affect its role in overall mercuryAuthorsJacob A. Fleck, Gary W. Gill, Brian A. Bergamaschi, Tamara E.C. Kraus, Bryan D. Downing, Charles N. AlpersOptical sensors for water quality
Shifts in land use, population, and climate have altered hydrologic systems in the United States in ways that affect water quality and ecosystem function. Water diversions, detention in reservoirs, increased channelization, and changes in rainfall and snowmelt are major causes, but there are also more subtle causes such as changes in soil temperature, atmospheric deposition, and shifting vegetatioAuthorsBrian A. Pellerin, Brian A. BergamaschiDOM composition in an agricultural watershed: assessing patterns and variability in the context of spatial scales
Willow Slough, a seasonally irrigated agricultural watershed in the Sacramento River valley, California, was sampled synoptically in order to investigate the extent to which dissolved organic carbon (DOC) concentrations and compositions from throughout the catchment are represented at the mouth. DOC concentrations ranged from 1.8 to 13.9 mg L−1, with the lowest values in headwater 1st and 2nd ordeAuthorsPeter J. Hernes, Robert G. M. Spencer, Rachel Y. Dyda, Brian A. Pellerin, Philip A. M. Bachand, Brian A. BergamaschiGroundwater contributions of flow, nitrate, and dissolved organic carbon to the lower San Joaquin River, California, 2006-08
The influence of groundwater on surface-water quality in the San Joaquin River, California, was examined for a 59-mile reach from the confluence with Salt Slough to Vernalis. The primary objective of this study was to quantify the rate of groundwater discharged to the lower San Joaquin River and the contribution of nitrate and dissolved organic carbon concentrations to the river. Multiple lines ofAuthorsCelia Zamora, Randy A. Dahlgren, Charles R. Kratzer, Bryan D. Downing, Ann D. Russell, Peter D. Dileanis, Brian A. Bergamaschi, Steven P. PhillipsThe role of irrigation runoff and winter rainfall on dissolved organic carbon loads in an agricultural watershed
We investigated the role of land use/land cover and agriculture practices on stream dissolved organic carbon (DOC) dynamics in the Willow Slough watershed (WSW) from 2006 to 2008. The 415 km2watershed in the northern Central Valley, California is covered by 31% of native vegetation and the remaining 69% of agricultural fields (primarily alfalfa, tomatoes, and rice). Stream discharge and weekly DOCAuthorsNeung-Hwan Oh, Brian A. Pellerin, Philip A.M. Bachand, Peter J. Hernes, Sandra M. Bachand, Noriaki Ohara, M. Levent Kavvas, Brian A. Bergamaschi, William R. HorwathOptical techniques for the determination of nitrate in environmental waters: Guidelines for instrument selection, operation, deployment, maintenance, quality assurance, and data reporting
The recent commercial availability of in situ optical sensors, together with new techniques for data collection and analysis, provides the opportunity to monitor a wide range of water-quality constituents on time scales in which environmental conditions actually change. Of particular interest is the application of ultraviolet (UV) photometers for in situ determination of nitrate concentrations inAuthorsBrian A. Pellerin, Brian A. Bergamaschi, Bryan D. Downing, John Franco Saraceno, Jessica D. Garrett, Lisa D. OlsenSources and characteristics of organic matter in the Clackamas River, Oregon, related to the formation of disinfection by-products in treated drinking water
This study characterized the amount and quality of organic matter in the Clackamas River, Oregon, to gain an understanding of sources that contribute to the formation of chlorinated and brominated disinfection by-products (DBPs), focusing on regulated DBPs in treated drinking water from two direct-filtration treatment plants that together serve approximately 100,000 customers. The central hypothesAuthorsKurt D. Carpenter, Tamara E.C. Kraus, Jami H. Goldman, John Franco Saraceno, Bryan D. Downing, Brian A. Bergamaschi, Gordon McGhee, Tracy TriplettMercury dynamics in a San Francisco estuary tidal wetland: assessing dynamics using in situ measurements
We used high-resolution in situ measurements of turbidity and fluorescent dissolved organic matter (FDOM) to quantitatively estimate the tidally driven exchange of mercury (Hg) between the waters of the San Francisco estuary and Browns Island, a tidal wetland. Turbidity and FDOM—representative of particle-associated and filter-passing Hg, respectively—together predicted 94 % of the observed variabAuthorsBrian A. Bergamaschi, Jacob A. Fleck, Bryan D. Downing, Emmanuel Boss, Brian A. Pellerin, Neil K. Ganju, David H. Schoellhamer, Amy A. Byington, Wesley A. Heim, Mark Stephenson, Roger FujiiBaseline and projected future carbon storage and greenhouse-gas fluxes in ecosystems of the Western United States
This assessment was conducted to fulfill the requirements of section 712 of the Energy Independence and Security Act (EISA) of 2007 and to improve understanding of carbon and greenhouse gas (GHG) fluxes in ecosystems of the Western United States. The assessment examined carbon storage, carbon fluxes, and other GHG fluxes (methane and nitrous oxide) in all major terrestrial ecosystems (forests, graAuthorsZhi-Liang Zhu, Bradley C. ReedNon-USGS Publications**
Bergamaschi, B.A. and Hedges, J.I. (1995) A Multichambered Apparatus for HF Solvolysis Experiments - Reaction of Cellulose HF Solvolysis Products with Acetic-Acid and Acetic-Anhydride. Carbohydrate Research 267, 115-126. https://doi.org/10.1016/0008-6215(94)00279-OHedges, J.I., Bergamaschi, B.A. and Benner, R. (1994) Comparative Analyses of DOC and DON in Natural Water - Erratum (Vol 41, Pg 121, 1989). Marine Chemistry 46, 407-408. https://doi.org/10.1016/0304-4203(94)90035-3Hedges, J.I., Bergamaschi, B.A. and Benner, R. (1993) Comparative Analyses of DOC and DON in Natural Water. Marine Chemistry 41, 121-134. https://doi.org/10.1016/0304-4203(93)90110-AHopkinson, C., Cifuentes, L., Burdige, D., Fitzwater, S., Hansell, D., Henrichs, S., Kahler, P., Koike, I., Walsh, T. and Bergamaschi, B. (1993) Measurement of Dissolved Organic Carbon and Nitrogen in Natural Waters - DON Subgroup Report. Marine Chemistry 41, 23-36. https://doi.org/10.1016/0304-4203(93)90103-UHedges, J.I. and Bergamaschi, B.A. (1992) Seawater Carbon Measurement. Nature 359, 202-202. https://doi.org/DOI 10.1038/359202a0**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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