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
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Comparison of XAD with other dissolved lignin isolation techniques and a compilation of analytical improvements for the analysis of lignin in aquatic settings Comparison 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...
Authors
Robert G. M. Spencer, George R. Aiken, Rachael Y. Dyda, Kenna D. Butler, Brian A. Bergamaschi, Peter J. Hernes
Fluorescence-based proxies for lignin in freshwater dissolved organic matter Fluorescence-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...
Authors
Peter J. Hernes, Brian A. Bergamaschi, Robert S. Eckard, Robert G.M. Spencer
High-frequency in situ optical measurements during a storm event: Assessing relationships between dissolved organic matter, sediment concentrations, and hydrologic processes High-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...
Authors
John Franco Saraceno, Brian A. Pellerin, Bryan D. Downing, Emmanuel Boss, Philip A. M. Bachand, Brian A. Bergamaschi
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 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
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...
Authors
Brian A. Pellerin, Bryan D. Downing, Carol Kendall, Randy A. Dahlgren, Tamara E.C. Kraus, John Franco Saraceno, Robert G. M. Spencer, Brian A. Bergamaschi
Quantifying fluxes and characterizing compositional changes of dissolved organic matter in aquatic systems in situ using combined acoustic and optical measurements Quantifying 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...
Authors
B.D. Downing, E. Boss, B.A. Bergamaschi, J.A. Fleck, M. A. Lionberger, N. K. Ganju, D. H. Schoellhamer, R. Fujii
Water quality Water 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...
Authors
Samuel N. Luoma, Susan Anderson, Brian A. Bergamaschi, Lisa Holm, Cathy Ruhl, David H. Schoellhamer, Robin Stewart
The role of hydrologic regimes on dissolved organic carbon composition in an agricultural watershed The role of hydrologic regimes on dissolved organic carbon composition in an agricultural watershed
Willow Slough, a seasonally irrigated agricultural watershed in the Sacramento River valley, California, was sampled weekly in 2006 in order to investigate seasonal concentrations and compositions of dissolved organic carbon (DOC). Average DOC concentrations nearly doubled from winter baseflow (2.75 mg L-1) to summer irrigation (5.14 mg L-1), while a concomitant increase in carbon...
Authors
P.J. Hernes, R.G.M. Spencer, R.Y. Dyda, B.A. Pellerin, P.A.M. Bachand, B.A. Bergamaschi
Assessing contribution of DOC from sediments to a drinking-water reservoir using optical profiling Assessing contribution of DOC from sediments to a drinking-water reservoir using optical profiling
Understanding the sources of dissolved organic carbon (DOC) in drinking-water reservoirs is an important management issue because DOC may form disinfection by-products, interfere with disinfection, or increase treatment costs. DOC may be derived from a host of sources-algal production of DOC in the reservoir, marginal production of DOC from mucks and vascular plants at the margins, and...
Authors
Bryan D. Downing, Brian A. Bergamaschi, David G. Evans, Emmanuel Boss
Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms
Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the ionophore monensin...
Authors
N. Watanabe, T.H. Harter, B.A. Bergamaschi
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 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
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...
Authors
T.E.C. Kraus, B.A. Bergamaschi, P.J. Hernes, R.G.M. Spencer, R. Stepanauskas, C. Kendall, R.F. Losee, R. Fujii
Land management impacts on dairy-derived dissolved organic carbon in ground water Land 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...
Authors
J.C. Chomycia, P.J. Hernes, T. Harter, B.A. Bergamaschi
Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms
Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the ionophore monensin...
Authors
N. Watanabe, T.H. Harter, B.A. Bergamaschi
Non-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-O
Hedges, 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)90035-3
Hedges, 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-A
Hopkinson, 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-U
Hedges, 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.
Science and Products
Filter Total Items: 22
Filter Total Items: 26
No Result Found
Filter Total Items: 114
Comparison of XAD with other dissolved lignin isolation techniques and a compilation of analytical improvements for the analysis of lignin in aquatic settings Comparison 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...
Authors
Robert G. M. Spencer, George R. Aiken, Rachael Y. Dyda, Kenna D. Butler, Brian A. Bergamaschi, Peter J. Hernes
Fluorescence-based proxies for lignin in freshwater dissolved organic matter Fluorescence-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...
Authors
Peter J. Hernes, Brian A. Bergamaschi, Robert S. Eckard, Robert G.M. Spencer
High-frequency in situ optical measurements during a storm event: Assessing relationships between dissolved organic matter, sediment concentrations, and hydrologic processes High-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...
Authors
John Franco Saraceno, Brian A. Pellerin, Bryan D. Downing, Emmanuel Boss, Philip A. M. Bachand, Brian A. Bergamaschi
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 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
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...
Authors
Brian A. Pellerin, Bryan D. Downing, Carol Kendall, Randy A. Dahlgren, Tamara E.C. Kraus, John Franco Saraceno, Robert G. M. Spencer, Brian A. Bergamaschi
Quantifying fluxes and characterizing compositional changes of dissolved organic matter in aquatic systems in situ using combined acoustic and optical measurements Quantifying 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...
Authors
B.D. Downing, E. Boss, B.A. Bergamaschi, J.A. Fleck, M. A. Lionberger, N. K. Ganju, D. H. Schoellhamer, R. Fujii
Water quality Water 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...
Authors
Samuel N. Luoma, Susan Anderson, Brian A. Bergamaschi, Lisa Holm, Cathy Ruhl, David H. Schoellhamer, Robin Stewart
The role of hydrologic regimes on dissolved organic carbon composition in an agricultural watershed The role of hydrologic regimes on dissolved organic carbon composition in an agricultural watershed
Willow Slough, a seasonally irrigated agricultural watershed in the Sacramento River valley, California, was sampled weekly in 2006 in order to investigate seasonal concentrations and compositions of dissolved organic carbon (DOC). Average DOC concentrations nearly doubled from winter baseflow (2.75 mg L-1) to summer irrigation (5.14 mg L-1), while a concomitant increase in carbon...
Authors
P.J. Hernes, R.G.M. Spencer, R.Y. Dyda, B.A. Pellerin, P.A.M. Bachand, B.A. Bergamaschi
Assessing contribution of DOC from sediments to a drinking-water reservoir using optical profiling Assessing contribution of DOC from sediments to a drinking-water reservoir using optical profiling
Understanding the sources of dissolved organic carbon (DOC) in drinking-water reservoirs is an important management issue because DOC may form disinfection by-products, interfere with disinfection, or increase treatment costs. DOC may be derived from a host of sources-algal production of DOC in the reservoir, marginal production of DOC from mucks and vascular plants at the margins, and...
Authors
Bryan D. Downing, Brian A. Bergamaschi, David G. Evans, Emmanuel Boss
Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms
Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the ionophore monensin...
Authors
N. Watanabe, T.H. Harter, B.A. Bergamaschi
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 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
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...
Authors
T.E.C. Kraus, B.A. Bergamaschi, P.J. Hernes, R.G.M. Spencer, R. Stepanauskas, C. Kendall, R.F. Losee, R. Fujii
Land management impacts on dairy-derived dissolved organic carbon in ground water Land 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...
Authors
J.C. Chomycia, P.J. Hernes, T. Harter, B.A. Bergamaschi
Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms
Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the ionophore monensin...
Authors
N. Watanabe, T.H. Harter, B.A. Bergamaschi
Non-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-O
Hedges, 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)90035-3
Hedges, 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-A
Hopkinson, 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-U
Hedges, 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.