Biogeochemistry Group Active
Hydrologic technicians deploying a flow sensor on a shoal in San Francisco Bay to investigate phytoplankton production and nutrient transformations.
A view from the office: USGS scientists heading out to deploy sensors for sediment nutrient storage and release in Rodeo Lagoon.
USGS laboratory technician filtering for chlorophyll-a.
Scientists aboard research vessel Aiken conduct water-quality mapping in support of wastewater-derived nutrients project.
The Biogeochemistry (BGC) Group uses an interdisciplinary approach to address surface water quality issues and food web dynamics throughout California, particularly in the Sacramento-San Joaquin Delta and San Francisco Bay.
Study areas include:
- Drivers of phytoplankton community composition and abundance and harmful algal bloom-related toxins
- Long-term continuous monitoring of numerous water quality constituents, phytoplankton, phytoplankton community structure, dissolved organic carbon and nitrogen as well as other constituents important to aquatic systems
- Changes in wastewater-derived nutrients and effects on phytoplankton community structure
- Effects of flow and water residence time on nutrient cycling and phytoplankton
- The impacts of invasive aquatic vegetation on water quality, water residence time, and native phytoplankton
- Assessing the role of wetlands in the Delta with respect to such topics as mercury, nutrients, drinking water quality and phytoplankton production
- Assessing the potential of tidal wetlands to mitigate land subsidence and sequester carbon
- Supporting improved water quality management through development of new sensors, analyses and techniques such as direct residence time measurements, custom sensor technologies, wide-area high-speed mapping surveys, remote sensing calibration and validation and other related activities
The BGC Group specializes in the application of in-situ optical sensors that monitor short- and long-term water quality trends. These sensors measure a host of biogeochemical parameters and capture continuous temporal trends – including those that may go undetected through traditional discrete sampling. The BGC Group also employs novel high-resolution boat-based mapping surveys, conducting intensive sampling for a diverse variety of biogeochemical parameters throughout the Bay-Delta.
These studies and data will help resource managers assess response to management actions and predict how the Bay-Delta will respond to future changes. The high frequency, real-time data can act as an early warning system for unanticipated, short-lived, or rapidly changing conditions, such as those due to spills, harmful algal blooms, and altered water-quality resulting from storms or levee breaches. The BGC group additionally specialize in the creation of novel data dissemination techniques in effort to ease open data acquisition, ultimately aiming to advance Bay-Delta science.
Additional Biogeochemistry Group staff include:
- Malanyon Adams
- Dulci Avouris
- Tom Bergamaschi
- Tim Baxter
- Heidi Bockisch
- Bryan Bonham
- Jake Brinkman
- Dylan Burau
- Jordy Conneely
- Ayelet Delascagigas
- Patrick Dellwo
- Nicholas Framsted
- Tommy (Hieu) Ly
- Andrea Jaegge
- Nathan Jumps
- Colin Keating
- Anne Le
- Ariana Maestas
- Kat Mai Cone
- Schuyler Nardelli
- Erica Nejad
- Dianna Oros
- Emily Richardson
- Tara Schraga
- Jesse Schroeder
- Jennifer Soto-Perez
- Corrine Sanford
- Crystal Sturgeon
- Maura Uebner
Below are other science projects associated with this project.
Below are multimedia items associated with this project.
Below are publications associated with this project.
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
Dissolved organic matter reduces algal accumulation of methylmercury
Seeing the light: the effects of particles, dissolved materials, and temperature on in situ measurements of DOM fluorescence in rivers and streams
Structural stability of coprecipitated natural organic matter and ferric iron under reducing conditions
In situ optical water-quality sensor networks - Workshop summary report
Tidally driven export of dissolved organic carbon, total mercury, and methylmercury from a mangrove-dominated estuary
Below are data or web applications associated with this project.
Below are news stories associated with this project.
Below are partners associated with this project.
- Overview
The Biogeochemistry (BGC) Group uses an interdisciplinary approach to address surface water quality issues and food web dynamics throughout California, particularly in the Sacramento-San Joaquin Delta and San Francisco Bay.
Study areas include:
- Drivers of phytoplankton community composition and abundance and harmful algal bloom-related toxins
- Long-term continuous monitoring of numerous water quality constituents, phytoplankton, phytoplankton community structure, dissolved organic carbon and nitrogen as well as other constituents important to aquatic systems
- Changes in wastewater-derived nutrients and effects on phytoplankton community structure
- Effects of flow and water residence time on nutrient cycling and phytoplankton
- The impacts of invasive aquatic vegetation on water quality, water residence time, and native phytoplankton
- Assessing the role of wetlands in the Delta with respect to such topics as mercury, nutrients, drinking water quality and phytoplankton production
- Assessing the potential of tidal wetlands to mitigate land subsidence and sequester carbon
- Supporting improved water quality management through development of new sensors, analyses and techniques such as direct residence time measurements, custom sensor technologies, wide-area high-speed mapping surveys, remote sensing calibration and validation and other related activities
The BGC Group specializes in the application of in-situ optical sensors that monitor short- and long-term water quality trends. These sensors measure a host of biogeochemical parameters and capture continuous temporal trends – including those that may go undetected through traditional discrete sampling. The BGC Group also employs novel high-resolution boat-based mapping surveys, conducting intensive sampling for a diverse variety of biogeochemical parameters throughout the Bay-Delta.
These studies and data will help resource managers assess response to management actions and predict how the Bay-Delta will respond to future changes. The high frequency, real-time data can act as an early warning system for unanticipated, short-lived, or rapidly changing conditions, such as those due to spills, harmful algal blooms, and altered water-quality resulting from storms or levee breaches. The BGC group additionally specialize in the creation of novel data dissemination techniques in effort to ease open data acquisition, ultimately aiming to advance Bay-Delta science.
Additional Biogeochemistry Group staff include:
- Malanyon Adams
- Dulci Avouris
- Tom Bergamaschi
- Tim Baxter
- Heidi Bockisch
- Bryan Bonham
- Jake Brinkman
- Dylan Burau
- Jordy Conneely
- Ayelet Delascagigas
- Patrick Dellwo
- Nicholas Framsted
- Tommy (Hieu) Ly
- Andrea Jaegge
- Nathan Jumps
- Colin Keating
- Anne Le
- Ariana Maestas
- Kat Mai Cone
- Schuyler Nardelli
- Erica Nejad
- Dianna Oros
- Emily Richardson
- Tara Schraga
- Jesse Schroeder
- Jennifer Soto-Perez
- Corrine Sanford
- Crystal Sturgeon
- Maura Uebner
- Science
Below are other science projects associated with this project.
Filter Total Items: 18 - Multimedia
Below are multimedia items associated with this project.
- Publications
Below are publications associated with this project.
Filter Total Items: 69DOM 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. ReedDissolved organic matter reduces algal accumulation of methylmercury
Dissolved organic matter (DOM) significantly decreased accumulation of methylmercury (MeHg) by the diatom Cyclotella meneghiniana in laboratory experiments. Live diatom cells accumulated two to four times more MeHg than dead cells, indicating that accumulation may be partially an energy-requiring process. Methylmercury enrichment in diatoms relative to ambient water was measured by a volume concenAuthorsAllison C. Luengen, Nicholas S. Fisher, Brian A. BergamaschiSeeing the light: the effects of particles, dissolved materials, and temperature on in situ measurements of DOM fluorescence in rivers and streams
Field-deployable sensors designed to continuously measure the fluorescence of colored dissolved organic matter (FDOM) in situ are of growing interest. However, the ability to make FDOM measurements that are comparable across sites and over time requires a clear understanding of how instrument characteristics and environmental conditions affect the measurements. In particular, the effects of waterAuthorsBryan D. Downing, Brian A. Pellerin, Brian A. Bergamaschi, John Franco Saraceno, Tamara E.C. KrausStructural stability of coprecipitated natural organic matter and ferric iron under reducing conditions
The objective was to assess the interaction of Fe coprecipitated with dissolved organic matter (DOM) and its effect on Fe (hydr)oxide crystallinity and DOM retention under abiotic reducing conditions. A Fe-based coagulant was reacted with DOM from an agricultural drain and the resulting precipitate (floc) was exposed to S(-II) and Fe(II). Solution concentrations of Fe(II/III) and DOM were monitoreAuthorsYumiko K. Henneberry, Tamara E.C. Kraus, Peter S. Nico, William R. HorwathIn situ optical water-quality sensor networks - Workshop summary report
Advanced in situ optical water-quality sensors and new techniques for data analysis hold enormous promise for furthering scientific understanding of aquatic systems. These sensors measure important biogeochemical parameters for long deployments, enabling the capture of data at time scales over which they vary most meaningfully. The high-frequency, real-time water-quality data they generate provideAuthorsBrian A. Pellerin, Brian A. Bergamaschi, Jeffery S. HorsburghTidally driven export of dissolved organic carbon, total mercury, and methylmercury from a mangrove-dominated estuary
The flux of dissolved organic carbon (DOC) from mangrove swamps accounts for 10% of the global terrestrial flux of DOC to coastal oceans. Recent findings of high concentrations of mercury (Hg) and methylmercury (MeHg) in mangroves, in conjunction with the common co-occurrence of DOC and Hg species, have raised concerns that mercury fluxes may also be large. We used a novel approach to estimate expAuthorsBrian A. Bergamaschi, D. P. Krabbenhoft, George Aiken, Eduardo Patino, D.G. Rumbold, William H. Orem - Web Tools
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- News
Below are news stories associated with this project.
- Partners
Below are partners associated with this project.