Jacob A Fleck
Jacob A Fleck - California Water Science Center
Science and Products
Filter Total Items: 28
Shallow Sediment Geochemistry in a Mercury-Contaminated Multi-Habitat Floodplain: Cache Creek Settling Basin, Yolo County, California (version 2.0, August 2021) Shallow Sediment Geochemistry in a Mercury-Contaminated Multi-Habitat Floodplain: Cache Creek Settling Basin, Yolo County, California (version 2.0, August 2021)
The Cache Creek Settling Basin (CCSB) is a 13.3 km2 leveed basin located at the terminal drainage of the Cache Creek watershed, immediately NE of the town of Woodland (Yolo County), California and approximately 18 km NW of Sacramento, California. The basin was constructed by the U.S. Army Corps of Engineers (completed in 1937 and modified in 1993) for the purpose of trapping suspended...
Data from the development and testing of a multiparameter standard solution for fluorescent dissolved organic matter (fDOM) and algal fluorescence (fChl) Data from the development and testing of a multiparameter standard solution for fluorescent dissolved organic matter (fDOM) and algal fluorescence (fChl)
Optical sensors measuring fluorescent dissolved organic matter (fDOM) are increasingly being used in water quality studies because they provide proxy measurements for dissolved organic matter concentrations (DOC). Similarly, chlorophyll-a (chl-a) fluorescence sensors have gained popularity as a means to measure phytoplankton concentration, biomass, and even primary productivity using...
Surface-Water Geochemistry of Mercury, Methylmercury, Nutrients, and other Constituents in Clear Lake, Lake County, California, July 2019 Surface-Water Geochemistry of Mercury, Methylmercury, Nutrients, and other Constituents in Clear Lake, Lake County, California, July 2019
Clear Lake is a 180 km2 freshwater lake located in the California Coast Range, approximately 120 km northwest of Sacramento. The lake supports a wide variety of fish and bird species and is a very popular sport-fishing destination. However, fish consumption advisories associated with mercury (Hg) contamination exist for several popular recreational species. The lake is comprised of three...
Geochemistry of shallow sediment including mercury, methylmercury and other constituents in the Cache Creek Settling Basin, Yolo County, California, 2010-16 Geochemistry of shallow sediment including mercury, methylmercury and other constituents in the Cache Creek Settling Basin, Yolo County, California, 2010-16
The Cache Creek Settling Basin (CCSB) is a 13.3 km2 leveed basin located at the terminal drainage of the Cache Creek watershed, immediately NE of the town of Woodland (Yolo County), California and approximately 18 km NW of Sacramento, California. The basin was constructed by the U.S. Army Corps of Engineers (completed in 1937 and modified in 1993) for the purpose of trapping suspended...
Filter Total Items: 41
Concurrent photolytic degradation of aqueous methylmercury and dissolved organic matter Concurrent 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...
Authors
Jacob A. Fleck, Gary W. Gill, Brian A. Bergamaschi, Tamara E.C. Kraus, Bryan D. Downing, Charles N. Alpers
Mercury cycling in agricultural and managed wetlands, Yolo Bypass, California: Spatial and seasonal variations in water quality Mercury cycling in agricultural and managed wetlands, Yolo Bypass, California: Spatial and seasonal variations in water quality
The seasonal and spatial variability of water quality, including mercury species, was evaluated in agricultural and managed, non-agricultural wetlands in the Yolo Bypass Wildlife Area, an area managed for multiple beneficial uses including bird habitat and rice farming. The study was conducted during an 11-month period (June 2007 to April 2008) that included a summer growing season and...
Authors
Charles N. Alpers, Jacob A. Fleck, Mark C. Marvin-DiPasquale, Craig A. Stricker, Mark Stephenson, Howard E. Taylor
Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study
With seasonal wetting and drying, and high biological productivity, agricultural wetlands (rice paddies) may enhance the conversion of inorganic mercury (Hg(II)) to methylmercury (MeHg), the more toxic, organic form that biomagnifies through food webs. Yet, the net balance of MeHg sources and sinks in seasonal wetland environments is poorly understood because it requires an annual...
Authors
Lisamarie Windham-Myers, Jacob A. Fleck, Joshua T. Ackerman, Mark C. Marvin-DiPasquale, Craig A. Stricker, Wesley A. Heim, Philip Bachand, Collin A. Eagles-Smith, Gary Gill, Mark Stephenson, Charles N. Alpers
Methylmercury production in and export from agricultural wetlands in California, USA: the need to account for physical transport processes into and out of the root zone Methylmercury production in and export from agricultural wetlands in California, USA: the need to account for physical transport processes into and out of the root zone
Concentration and mass balance analyses were used to quantify methylmercury (MeHg) loads from conventional (white) rice, wild rice, and fallowed fields in northern California's Yolo Bypass. These analyses were standardized against chloride to distinguish transport pathways and net ecosystem production (NEP). During summer, chloride loads were both exported with surface water and moved...
Authors
Philip Bachand, Sandra M. Bachand, Jacob A. Fleck, Charles N. Alpers, Mark Stephenson, Lisamarie Windham-Myers
Mercury cycling in agricultural and managed wetlands of California: seasonal influences of vegetation on mercury methylation, storage, and transport Mercury cycling in agricultural and managed wetlands of California: seasonal influences of vegetation on mercury methylation, storage, and transport
Plants are a dominant biologic and physical component of many wetland capable of influencing the internal pools and fluxes of methylmercury (MeHg). To investigate their role with respect to the latter, we examined the changing seasonal roles of vegetation biomass and Hg, C and N composition from May 2007-February 2008 in 3 types of agricultural wetlands (domesticated or white rice, wild...
Authors
Lisamarie Windham-Myers, Mark C. Marvin-DiPasquale, Evangelos Kakouros, Jennifer L. Agee, Le H. Kieu, Craig A. Stricker, Jacob A. Fleck, Joshua T. Ackerman
Mercury dynamics in a San Francisco estuary tidal wetland: assessing dynamics using in situ measurements Mercury 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...
Authors
Brian 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 Fujii
Methyl mercury dynamics in a tidal wetland quantified using in situ optical measurements Methyl mercury dynamics in a tidal wetland quantified using in situ optical measurements
We assessed monomethylmercury (MeHg) dynamics in a tidal wetland over three seasons using a novel method that employs a combination of in situ optical measurements as concentration proxies. MeHg concentrations measured over a single spring tide were extended to a concentration time series using in situ optical measurements. Tidal fluxes were calculated using modeled concentrations and bi
Authors
B.A. Bergamaschi, J.A. Fleck, B.D. Downing, E. Boss, B. Pellerin, N. K. Ganju, D. H. Schoellhamer, A.A. Byington, W.A. Heim, M. Stephenson, R. Fujii
The effects of sediment and mercury mobilization in the South Yuba River and Humbug Creek confluence area, Nevada County, California: Concentrations, speciation, and environmental fate – Part 1: Field characterization The effects of sediment and mercury mobilization in the South Yuba River and Humbug Creek confluence area, Nevada County, California: Concentrations, speciation, and environmental fate – Part 1: Field characterization
Millions of pounds of mercury (Hg) were deposited in the river and stream channels of the Sierra Nevada from placer and hard-rock mining operations in the late 1800s and early 1900s. The resulting contaminated sediments are relatively harmless when buried and isolated from the overlying aquatic environment. The entrained Hg in the sediment constitutes a potential risk to human and...
Authors
Jacob A. Fleck, Charles N. Alpers, Mark Marvin-DiPasquale, Roger L. Hothem, Scott Wright, Kevin Ellett, Elizabeth Beaulieu, Jennifer L. Agee, Evangelos Kakouros, Le H. Kieu, Dennis D. Eberl, Alex E. Blum, Jason T. May
The effects of sediment and mercury mobilization in the South Yuba River and Humbug Creek confluence area, Nevada County, California: Concentrations, speciation and environmental fate - Part 2: Laboratory Experiments The effects of sediment and mercury mobilization in the South Yuba River and Humbug Creek confluence area, Nevada County, California: Concentrations, speciation and environmental fate - Part 2: Laboratory Experiments
No abstract available.
Authors
Mark Marvin-DiPasquale, Jennifer L. Agee, Eangelos Kakouros, Le H. Kieu, Jacob A. Fleck, Charles N. Alpers
Removal of inorganic mercury and methylmercury from surface waters following coagulation of dissolved organic matter with metal-based salts Removal of inorganic mercury and methylmercury from surface waters following coagulation of dissolved organic matter with metal-based salts
The presence of inorganic mercury (IHg) and methylmercury (MeHg) in surface waters is a health concern worldwide. This study assessed the removal potential use of metal-based coagulants as a means to remove both dissolved IHg and MeHg from natural waters and provides information regarding the importance of Hg associations with the dissolved organic matter (DOM) fraction and metal...
Authors
Y.K. Henneberry, T.E.C. Kraus, J.A. Fleck, David P. Krabbenhoft, P.M. Bachand, W.R. Horwath
Methylmercury cycling, bioaccumulation, and export from agricultural and non-agricultural wetlands in the Yolo Bypass Methylmercury cycling, bioaccumulation, and export from agricultural and non-agricultural wetlands in the Yolo Bypass
This 18-month field study addresses the seasonal and spatial patterns and processes controlling methylmercury (MeHg) production, bioaccumulation, and export from natural and agricultural wetlands of the Yolo Bypass Wildlife Area (YBWA). The data were collected in conjuntion with a Proposition 40 grant from the State Water Resources Control Board in support of the development of Best...
Authors
Lisamarie Windham-Myers, Mark Marvin-DiPasquale, Jacob Fleck, Charles N. Alpers, Joshua T. Ackerman, Collin A. Eagles-Smith, Craig Stricker, Mark Stephenson, David Feliz, Gary Gill, Philip Bachand, Ann Brice, Robin Kulakow
Mercury, methylmercury, and other constituents in sediment and water from seasonal and permanent wetlands in the Cache Creek settling basin and Yolo Bypass, Yolo County, California, 2005-06 Mercury, methylmercury, and other constituents in sediment and water from seasonal and permanent wetlands in the Cache Creek settling basin and Yolo Bypass, Yolo County, California, 2005-06
This report presents surface water and surface (top 0-2 cm) sediment geochemical data collected during 2005-2006, as part of a larger study of mercury (Hg) dynamics in seasonal and permanently flooded wetland habitats within the lower Sacramento River basin, Yolo County, California. The study was conducted in two phases. Phase I represented reconnaissance sampling and included three...
Authors
Mark Marvin-DiPasquale, Charles N. Alpers, Jacob A. Fleck
Science and Products
Filter Total Items: 28
Shallow Sediment Geochemistry in a Mercury-Contaminated Multi-Habitat Floodplain: Cache Creek Settling Basin, Yolo County, California (version 2.0, August 2021) Shallow Sediment Geochemistry in a Mercury-Contaminated Multi-Habitat Floodplain: Cache Creek Settling Basin, Yolo County, California (version 2.0, August 2021)
The Cache Creek Settling Basin (CCSB) is a 13.3 km2 leveed basin located at the terminal drainage of the Cache Creek watershed, immediately NE of the town of Woodland (Yolo County), California and approximately 18 km NW of Sacramento, California. The basin was constructed by the U.S. Army Corps of Engineers (completed in 1937 and modified in 1993) for the purpose of trapping suspended...
Data from the development and testing of a multiparameter standard solution for fluorescent dissolved organic matter (fDOM) and algal fluorescence (fChl) Data from the development and testing of a multiparameter standard solution for fluorescent dissolved organic matter (fDOM) and algal fluorescence (fChl)
Optical sensors measuring fluorescent dissolved organic matter (fDOM) are increasingly being used in water quality studies because they provide proxy measurements for dissolved organic matter concentrations (DOC). Similarly, chlorophyll-a (chl-a) fluorescence sensors have gained popularity as a means to measure phytoplankton concentration, biomass, and even primary productivity using...
Surface-Water Geochemistry of Mercury, Methylmercury, Nutrients, and other Constituents in Clear Lake, Lake County, California, July 2019 Surface-Water Geochemistry of Mercury, Methylmercury, Nutrients, and other Constituents in Clear Lake, Lake County, California, July 2019
Clear Lake is a 180 km2 freshwater lake located in the California Coast Range, approximately 120 km northwest of Sacramento. The lake supports a wide variety of fish and bird species and is a very popular sport-fishing destination. However, fish consumption advisories associated with mercury (Hg) contamination exist for several popular recreational species. The lake is comprised of three...
Geochemistry of shallow sediment including mercury, methylmercury and other constituents in the Cache Creek Settling Basin, Yolo County, California, 2010-16 Geochemistry of shallow sediment including mercury, methylmercury and other constituents in the Cache Creek Settling Basin, Yolo County, California, 2010-16
The Cache Creek Settling Basin (CCSB) is a 13.3 km2 leveed basin located at the terminal drainage of the Cache Creek watershed, immediately NE of the town of Woodland (Yolo County), California and approximately 18 km NW of Sacramento, California. The basin was constructed by the U.S. Army Corps of Engineers (completed in 1937 and modified in 1993) for the purpose of trapping suspended...
Filter Total Items: 41
Concurrent photolytic degradation of aqueous methylmercury and dissolved organic matter Concurrent 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...
Authors
Jacob A. Fleck, Gary W. Gill, Brian A. Bergamaschi, Tamara E.C. Kraus, Bryan D. Downing, Charles N. Alpers
Mercury cycling in agricultural and managed wetlands, Yolo Bypass, California: Spatial and seasonal variations in water quality Mercury cycling in agricultural and managed wetlands, Yolo Bypass, California: Spatial and seasonal variations in water quality
The seasonal and spatial variability of water quality, including mercury species, was evaluated in agricultural and managed, non-agricultural wetlands in the Yolo Bypass Wildlife Area, an area managed for multiple beneficial uses including bird habitat and rice farming. The study was conducted during an 11-month period (June 2007 to April 2008) that included a summer growing season and...
Authors
Charles N. Alpers, Jacob A. Fleck, Mark C. Marvin-DiPasquale, Craig A. Stricker, Mark Stephenson, Howard E. Taylor
Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study
With seasonal wetting and drying, and high biological productivity, agricultural wetlands (rice paddies) may enhance the conversion of inorganic mercury (Hg(II)) to methylmercury (MeHg), the more toxic, organic form that biomagnifies through food webs. Yet, the net balance of MeHg sources and sinks in seasonal wetland environments is poorly understood because it requires an annual...
Authors
Lisamarie Windham-Myers, Jacob A. Fleck, Joshua T. Ackerman, Mark C. Marvin-DiPasquale, Craig A. Stricker, Wesley A. Heim, Philip Bachand, Collin A. Eagles-Smith, Gary Gill, Mark Stephenson, Charles N. Alpers
Methylmercury production in and export from agricultural wetlands in California, USA: the need to account for physical transport processes into and out of the root zone Methylmercury production in and export from agricultural wetlands in California, USA: the need to account for physical transport processes into and out of the root zone
Concentration and mass balance analyses were used to quantify methylmercury (MeHg) loads from conventional (white) rice, wild rice, and fallowed fields in northern California's Yolo Bypass. These analyses were standardized against chloride to distinguish transport pathways and net ecosystem production (NEP). During summer, chloride loads were both exported with surface water and moved...
Authors
Philip Bachand, Sandra M. Bachand, Jacob A. Fleck, Charles N. Alpers, Mark Stephenson, Lisamarie Windham-Myers
Mercury cycling in agricultural and managed wetlands of California: seasonal influences of vegetation on mercury methylation, storage, and transport Mercury cycling in agricultural and managed wetlands of California: seasonal influences of vegetation on mercury methylation, storage, and transport
Plants are a dominant biologic and physical component of many wetland capable of influencing the internal pools and fluxes of methylmercury (MeHg). To investigate their role with respect to the latter, we examined the changing seasonal roles of vegetation biomass and Hg, C and N composition from May 2007-February 2008 in 3 types of agricultural wetlands (domesticated or white rice, wild...
Authors
Lisamarie Windham-Myers, Mark C. Marvin-DiPasquale, Evangelos Kakouros, Jennifer L. Agee, Le H. Kieu, Craig A. Stricker, Jacob A. Fleck, Joshua T. Ackerman
Mercury dynamics in a San Francisco estuary tidal wetland: assessing dynamics using in situ measurements Mercury 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...
Authors
Brian 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 Fujii
Methyl mercury dynamics in a tidal wetland quantified using in situ optical measurements Methyl mercury dynamics in a tidal wetland quantified using in situ optical measurements
We assessed monomethylmercury (MeHg) dynamics in a tidal wetland over three seasons using a novel method that employs a combination of in situ optical measurements as concentration proxies. MeHg concentrations measured over a single spring tide were extended to a concentration time series using in situ optical measurements. Tidal fluxes were calculated using modeled concentrations and bi
Authors
B.A. Bergamaschi, J.A. Fleck, B.D. Downing, E. Boss, B. Pellerin, N. K. Ganju, D. H. Schoellhamer, A.A. Byington, W.A. Heim, M. Stephenson, R. Fujii
The effects of sediment and mercury mobilization in the South Yuba River and Humbug Creek confluence area, Nevada County, California: Concentrations, speciation, and environmental fate – Part 1: Field characterization The effects of sediment and mercury mobilization in the South Yuba River and Humbug Creek confluence area, Nevada County, California: Concentrations, speciation, and environmental fate – Part 1: Field characterization
Millions of pounds of mercury (Hg) were deposited in the river and stream channels of the Sierra Nevada from placer and hard-rock mining operations in the late 1800s and early 1900s. The resulting contaminated sediments are relatively harmless when buried and isolated from the overlying aquatic environment. The entrained Hg in the sediment constitutes a potential risk to human and...
Authors
Jacob A. Fleck, Charles N. Alpers, Mark Marvin-DiPasquale, Roger L. Hothem, Scott Wright, Kevin Ellett, Elizabeth Beaulieu, Jennifer L. Agee, Evangelos Kakouros, Le H. Kieu, Dennis D. Eberl, Alex E. Blum, Jason T. May
The effects of sediment and mercury mobilization in the South Yuba River and Humbug Creek confluence area, Nevada County, California: Concentrations, speciation and environmental fate - Part 2: Laboratory Experiments The effects of sediment and mercury mobilization in the South Yuba River and Humbug Creek confluence area, Nevada County, California: Concentrations, speciation and environmental fate - Part 2: Laboratory Experiments
No abstract available.
Authors
Mark Marvin-DiPasquale, Jennifer L. Agee, Eangelos Kakouros, Le H. Kieu, Jacob A. Fleck, Charles N. Alpers
Removal of inorganic mercury and methylmercury from surface waters following coagulation of dissolved organic matter with metal-based salts Removal of inorganic mercury and methylmercury from surface waters following coagulation of dissolved organic matter with metal-based salts
The presence of inorganic mercury (IHg) and methylmercury (MeHg) in surface waters is a health concern worldwide. This study assessed the removal potential use of metal-based coagulants as a means to remove both dissolved IHg and MeHg from natural waters and provides information regarding the importance of Hg associations with the dissolved organic matter (DOM) fraction and metal...
Authors
Y.K. Henneberry, T.E.C. Kraus, J.A. Fleck, David P. Krabbenhoft, P.M. Bachand, W.R. Horwath
Methylmercury cycling, bioaccumulation, and export from agricultural and non-agricultural wetlands in the Yolo Bypass Methylmercury cycling, bioaccumulation, and export from agricultural and non-agricultural wetlands in the Yolo Bypass
This 18-month field study addresses the seasonal and spatial patterns and processes controlling methylmercury (MeHg) production, bioaccumulation, and export from natural and agricultural wetlands of the Yolo Bypass Wildlife Area (YBWA). The data were collected in conjuntion with a Proposition 40 grant from the State Water Resources Control Board in support of the development of Best...
Authors
Lisamarie Windham-Myers, Mark Marvin-DiPasquale, Jacob Fleck, Charles N. Alpers, Joshua T. Ackerman, Collin A. Eagles-Smith, Craig Stricker, Mark Stephenson, David Feliz, Gary Gill, Philip Bachand, Ann Brice, Robin Kulakow
Mercury, methylmercury, and other constituents in sediment and water from seasonal and permanent wetlands in the Cache Creek settling basin and Yolo Bypass, Yolo County, California, 2005-06 Mercury, methylmercury, and other constituents in sediment and water from seasonal and permanent wetlands in the Cache Creek settling basin and Yolo Bypass, Yolo County, California, 2005-06
This report presents surface water and surface (top 0-2 cm) sediment geochemical data collected during 2005-2006, as part of a larger study of mercury (Hg) dynamics in seasonal and permanently flooded wetland habitats within the lower Sacramento River basin, Yolo County, California. The study was conducted in two phases. Phase I represented reconnaissance sampling and included three...
Authors
Mark Marvin-DiPasquale, Charles N. Alpers, Jacob A. Fleck