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
Use and environmental occurrence of pharmaceuticals in freestall dairy farms with manured forage fields
Microbial degradation of plant leachate alters lignin phenols and trihalomethane precursors
Identifying sources of dissolved organic carbon in agriculturally dominated rivers using radiocarbon age dating: Sacramento-San Joaquin River Basin, California
Determining sources of dissolved organic carbon and disinfection byproduct precursors to the McKenzie River, Oregon
Comparison of XAD with other dissolved lignin isolation techniques and a compilation of analytical improvements for the analysis of lignin in aquatic settings
Assessing the sources and magnitude of diurnal nitrate variability in the San Joaquin River (California) with an in situ optical nitrate sensor and dual nitrate isotopes
Quantifying fluxes and characterizing compositional changes of dissolved organic matter in aquatic systems in situ using combined acoustic and optical measurements
High-frequency in situ optical measurements during a storm event: Assessing relationships between dissolved organic matter, sediment concentrations, and hydrologic processes
Fluorescence-based proxies for lignin in freshwater dissolved organic matter
Water quality
Land management impacts on dairy-derived dissolved organic carbon in ground water
Assessing the contribution of wetlands and subsided islands to dissolved organic matter and disinfection byproduct precursors in the Sacramento-San Joaquin River Delta: A geochemical approach
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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Use and environmental occurrence of pharmaceuticals in freestall dairy farms with manured forage fields
Environmental releases of antibiotics from concentrated animal feeding operations (CAFOs) are of increasing regulatory concern. This study investigates the use and occurrence of antibiotics in dairy CAFOs and their potential transport into first-encountered groundwater. On two dairies we conducted four seasonal sampling campaigns, each across 13 animal production and waste management systems and aAuthorsNaoko Watanabe, Brian A. Bergamaschi, Keith A. Loftin, Michael T. Meyer, Thomas HarterMicrobial degradation of plant leachate alters lignin phenols and trihalomethane precursors
Although the importance of vascular plant-derived dissolved organic carbon (DOC) in freshwater systems has been studied, the role of leached DOC as precursors of disinfection byproducts (DBPs) during drinking water treatment is not well known. Here we measured the propensity of leachates from four crops and four aquatic macrophytes to form trihalomethanes (THMs)—a regulated class of DBPs—before anAuthorsBrian A. Pellerin, Peter J. Hernes, John Franco Saraceno, Robert G.M. Spencer, Brian A. BergamaschiIdentifying sources of dissolved organic carbon in agriculturally dominated rivers using radiocarbon age dating: Sacramento-San Joaquin River Basin, California
We used radiocarbon measurements of dissolved organic carbon (DOC) to resolve sources of riverine carbon within agriculturally dominated landscapes in California. During 2003 and 2004, average Δ14C for DOC was −254‰ in agricultural drains in the Sacramento–San Joaquin Delta, −218‰ in the San Joaquin River, −175‰ in the California State Water Project and −152‰ in the Sacramento River. The age of buAuthorsJames O. Sickman, Carol L. DiGiorgio, M. Lee Davisson, Delores M. Lucero, Brian A. BergamaschiDetermining sources of dissolved organic carbon and disinfection byproduct precursors to the McKenzie River, Oregon
This study was conducted to determine the main sources of dissolved organic carbon (DOC) and disinfection byproduct (DBP) precursors to the McKenzie River, Oregon (USA). Water samples collected from the mainstem, tributaries, and reservoir outflows were analyzed for DOC concentration and DBP formation potentials (trihalomethanes [THMFPs] and haloacetic acids [HAAFPs]). In addition, optical propertAuthorsTamara E.C. Kraus, Chauncey W. Anderson, Karl Morgenstern, Bryan D. Downing, Brian A. Pellerin, Brian A. BergamaschiComparison of XAD with other dissolved lignin isolation techniques and a compilation of analytical improvements for the analysis of lignin in aquatic settings
This manuscript highlights numerous incremental improvements in dissolved lignin measurements over the nearly three decades since CuO oxidation of lignin phenols was first adapted for environmental samples. Intercomparison of the recovery efficiency of three common lignin phenol concentration and isolation techniques, namely XAD, C18with both CH3OH (C18M) and CH3CN (C18A) used independently for prAuthorsRobert G. M. Spencer, George R. Aiken, Rachael Y. Dyda, Kenna D. Butler, Brian A. Bergamaschi, Peter J. HernesAssessing the sources and magnitude of diurnal nitrate variability in the San Joaquin River (California) with an in situ optical nitrate sensor and dual nitrate isotopes
1. We investigated diurnal nitrate (NO3−) concentration variability in the San Joaquin River using an in situ optical NO3− sensor and discrete sampling during a 5‐day summer period characterized by high algal productivity. Dual NO3− isotopes (δ15NNO3 and δ18ONO3) and dissolved oxygen isotopes (δ18ODO) were measured over 2 days to assess NO3− sources and biogeochemical controls over diurnal time‐scAuthorsBrian A. Pellerin, Bryan D. Downing, Carol Kendall, Randy A. Dahlgren, Tamara E.C. Kraus, John Franco Saraceno, Robert G. M. Spencer, Brian A. BergamaschiQuantifying fluxes and characterizing compositional changes of dissolved organic matter in aquatic systems in situ using combined acoustic and optical measurements
Studying the dynamics and geochemical behavior of dissolved and particulate organic material is difficult because concentration and composition may rapidly change in response to aperiodic as well as periodic physical and biological forcing. Here we describe a method useful for quantifying fluxes and analyzing dissolved organic matter (DOM) dynamics. The method uses coupled optical and acoustic meaAuthorsB.D. Downing, E. Boss, B.A. Bergamaschi, J.A. Fleck, M. A. Lionberger, N. K. Ganju, D. H. Schoellhamer, R. FujiiHigh-frequency in situ optical measurements during a storm event: Assessing relationships between dissolved organic matter, sediment concentrations, and hydrologic processes
Dissolved organic matter (DOM) dynamics during storm events has received considerable attention in forested watersheds, but the extent to which storms impart rapid changes in DOM concentration and composition in highly disturbed agricultural watersheds remains poorly understood. In this study, we used identical in situ optical sensors for DOM fluorescence (FDOM) with and without filtration to contAuthorsJohn Franco Saraceno, Brian A. Pellerin, Bryan D. Downing, Emmanuel Boss, Philip A. M. Bachand, Brian A. BergamaschiFluorescence-based proxies for lignin in freshwater dissolved organic matter
Lignin phenols have proven to be powerful biomarkers in environmental studies; however, the complexity of lignin analysis limits the number of samples and thus spatial and temporal resolution in any given study. In contrast, spectrophotometric characterization of dissolved organic matter (DOM) is rapid, noninvasive, relatively inexpensive, requires small sample volumes, and can even be measured inAuthorsPeter J. Hernes, Brian A. Bergamaschi, Robert S. Eckard, Robert G.M. SpencerWater quality
Sustainable water policy in California will require maintaining or improving water quality. The Delta is an important source of drinking water for Californians, but sustaining a quality sufficient for human and agricultural consumption presents a number of problems and challenges to water managers. Similarly, poor environmental water quality is recognized as one of the influential stressors contriAuthorsSamuel N. Luoma, Susan Anderson, Brian A. Bergamaschi, Lisa Holm, Cathy Ruhl, David H. Schoellhamer, Robin StewartLand management impacts on dairy-derived dissolved organic carbon in ground water
Dairy operations have the potential to elevate dissolved organic carbon (DOC) levels in ground water, where it may interact with organic and inorganic contaminants, fuel denitrification, and may present problems for drinking water treatment. Total and percent bioavailable DOC and total and carbon-specific trihalomethane (THM) formation potential (TTHMFP and STHMFP, respectively) were determined foAuthorsJ.C. Chomycia, P.J. Hernes, T. Harter, B.A. BergamaschiAssessing the contribution of wetlands and subsided islands to dissolved organic matter and disinfection byproduct precursors in the Sacramento-San Joaquin River Delta: A geochemical approach
This study assesses how rivers, wetlands, island drains and open water habitats within the Sacramento-San Joaquin River Delta affect dissolved organic matter (DOM) content and composition, and disinfection byproduct (DBP) formation. Eleven sites representative of these habitats were sampled on six dates to encompass seasonal variability. Using a suite of qualitative analyses, including specific DBAuthorsT.E.C. Kraus, B.A. Bergamaschi, P.J. Hernes, R.G.M. Spencer, R. Stepanauskas, C. Kendall, R.F. Losee, R. FujiiNon-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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