Skip to main content
U.S. flag

An official website of the United States government

Francis Parchaso

Francis Parchaso is a Biologist for the USGS Water Resources Mission Area.

Science and Products

Benthic Communities as Mediators of Water Quality in Lower San Francisco Bay, California (2012-2019)

San Francisco Bay and Estuary is largely urbanized and developed, and the southern bay is the most urbanized with many sources of nutrients, many concerns that the system might become eutrophic, and many questions about how South Bay has maintained its relatively good health. The hypotheses for why South Bay is not eutrophic, where other bays have not been so fortunate, include high bivalve grazin
By
Water Resources Mission Area

Data for monitoring trace metal and benthic community near the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay, California (ver 2.0, November 2022)

Trace-metal concentrations in sediment and in the clam Limecola petalum (World Register of Marine Species, 2020; formerly reported as Macoma balthica and M. petalum), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat located 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Fran
By
Water Resources Mission Area

Bivalve metrics in the North San Francisco Bay and Sacramento-San Joaquin Delta

Phytoplankton is an important and limiting food source in the Sacramento-San Joaquin Delta and San Francisco Bay; the decline of phytoplankton biomass is one possible factor in the pelagic organism decline and specifically in the decline of the protected delta smelt. The bivalves Corbicula fluminea and Potamocorbula amurensis (hereafter Corbicula and Potamocorbula, respectively) have been shown to
By
Water Resources Mission Area

Priority Ecosystem Science Program: benthic community and bivalve metrics data in Grizzly Bay and San Pablo Bay (2019-20)

Sediments and sediment transport influence the physical habitat and the ecology of the San Francisco Bay estuary. Bed sediments provide habitat for benthic organisms and the transport of sediment transports nutrients and contaminants throughout the San Francisco Bay. As part of the SF Bay-Delta Priority Ecosystems Science Program project: Biophysical Controls on Erosion and Near-Bed Turbulence: St
By
Water Resources Mission Area

A spatially and temporally intensive sampling study of benthic community and bivalve metrics in the Sacramento-San Joaquin Delta, 2007-18

Phytoplankton is an important and limiting food source in the Sacramento-San Joaquin Delta and San Francisco Bay; the decline of phytoplankton biomass is one possible factor in the pelagic organism decline and specifically in the decline of the protected delta smelt. The bivalves Corbicula fluminea and Potamocorbula amurensis (hereafter Corbicula and Potamocorbula, respectively) have been shown to
By
Water Resources Mission Area

Benthic Community and Bivalve Metrics Data in the Sacramento - San Joaquin Delta from 2015 to 2018

Declining phytoplankton biomass and the resulting stress on the food web has been suggested as one contributor to the decline of Delta Smelt and other fish species in the San Francisco Bay (SFB) and the Sacramento San Joaquin River Delta. Filter feeding by two species of bivalves, Corbicula fluminea and Potamocorbula amurensis, has been shown to control phytoplankton growth rate in the SFB and Del
By
Water Resources Mission Area
Moutain Diablo in the early morning
Mt. Diablo from Suisun Marsh
Mt. Diablo from Suisun Marsh
Moutain Diablo in the early morning

Mt. Diablo from Suisun Marsh

Mt. Diablo from Suisun Marsh

Picturesque view of Mt.Diablo early in the morning from Suisun Marsh.

Moutain Diablo in the early morning

Mt. Diablo from Suisun Marsh

Mt. Diablo from Suisun Marsh

Picturesque view of Mt.Diablo early in the morning from Suisun Marsh.

Water quality sampling using a Niskin sampler from the Research Vessel Polaris at sunset on San Francisco Bay.
Water quality sampling on San Francisco Bay
Water quality sampling on San Francisco Bay
Water quality sampling using a Niskin sampler from the Research Vessel Polaris at sunset on San Francisco Bay.

Water quality sampling on San Francisco Bay

Water quality sampling on San Francisco Bay

USGS conducts water quality sampling to describe changes in water quality along the deep channel of the San Francisco Bay-Delta system. Sampling includes continuious sampling and discrete sampling. Here a water discrete water sample is collected using a Niskin sampler at sunset in north San Francisco Bay.

By
Water Resources
Water quality sampling using a Niskin sampler from the Research Vessel Polaris at sunset on San Francisco Bay.

Water quality sampling on San Francisco Bay

Water quality sampling on San Francisco Bay

USGS conducts water quality sampling to describe changes in water quality along the deep channel of the San Francisco Bay-Delta system. Sampling includes continuious sampling and discrete sampling. Here a water discrete water sample is collected using a Niskin sampler at sunset in north San Francisco Bay.

By
Water Resources
Image: Research Vessel Polaris
Research Vessel Polaris
Research Vessel Polaris
Image: Research Vessel Polaris

Research Vessel Polaris

Research Vessel Polaris

San Fracisco Bay, CA; Amy Little on Research Vessel Polaris, sampling for water quality constitutents.

By
Water Resources, Communications and Publishing
Image: Research Vessel Polaris

Research Vessel Polaris

Research Vessel Polaris

San Fracisco Bay, CA; Amy Little on Research Vessel Polaris, sampling for water quality constitutents.

By
Water Resources, Communications and Publishing
Image: Suisun Slough, California
Suisun Slough, California
Suisun Slough, California
Image: Suisun Slough, California

Suisun Slough, California

Suisun Slough, California

A small slough in Suisun Slough in the Suisun Bay, California.

By
Ecosystems, Communications and Publishing
Image: Suisun Slough, California

Suisun Slough, California

Suisun Slough, California

A small slough in Suisun Slough in the Suisun Bay, California.

By
Ecosystems, Communications and Publishing
Image: Golden Gate Bridge, California
Golden Gate Bridge, California
Golden Gate Bridge, California
Image: Golden Gate Bridge, California

Golden Gate Bridge, California

Golden Gate Bridge, California

The Golden Gate Bridge seen through Racoon Strait in the San Francisco Bay, California.

By
Ecosystems, Communications and Publishing
Image: Golden Gate Bridge, California

Golden Gate Bridge, California

Golden Gate Bridge, California

The Golden Gate Bridge seen through Racoon Strait in the San Francisco Bay, California.

By
Ecosystems, Communications and Publishing
Image: Sunrise on the Suisun Bay
Sunrise on the Suisun Bay
Sunrise on the Suisun Bay
Image: Sunrise on the Suisun Bay

Sunrise on the Suisun Bay

Sunrise on the Suisun Bay

Sunrise peering through early morning tule fog in Suisun Bay, California.

By
Ecosystems, Communications and Publishing
Image: Sunrise on the Suisun Bay

Sunrise on the Suisun Bay

Sunrise on the Suisun Bay

Sunrise peering through early morning tule fog in Suisun Bay, California.

By
Ecosystems, Communications and Publishing
Image: Sunrise on the Sacramento River
Sunrise on the Sacramento River
Sunrise on the Sacramento River
Image: Sunrise on the Sacramento River

Sunrise on the Sacramento River

Sunrise on the Sacramento River

Sunrise reflecting on a November morning on the Sacramento River, California.

By
Ecosystems, Communications and Publishing
Image: Sunrise on the Sacramento River

Sunrise on the Sacramento River

Sunrise on the Sacramento River

Sunrise reflecting on a November morning on the Sacramento River, California.

By
Ecosystems, Communications and Publishing
Filter Total Items: 47

Physics to fish—Understanding the factors that create and sustain native fish habitat in the San Francisco Estuary

Executive SummaryThe Bureau of Reclamation (Reclamation) operates the Central Valley Project (CVP), one of the nation’s largest water projects. Reclamation has an ongoing need to improve the scientific basis for adaptive management of the CVP and, by extension, joint operations with California’s State Water Project. The U.S. Geological Survey (USGS) works cooperatively with the Bureau of Reclamati
Authors
Larry R. Brown, David E. Ayers, Brian A. Bergamaschi, Jon R. Burau, Evan T. Dailey, Bryan D. Downing, Maureen A. Downing-Kunz, Frederick V. Feyrer, Brock M. Huntsman, Tamara E. C. Kraus, Tara Morgan, Jessica R. Lacy, Francis Parchaso, Catherine A. Ruhl, Elizabeth B. Stumpner, Paul Stumpner, Janet Thompson, Matthew J. Young
By
Water Resources Mission Area, California Water Science Center, Pacific Coastal and Marine Science Center

Near-field receiving-water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California—2020

Trace-metal concentrations in sediment and in the clam Limecola petalum (World Register of Marine Species, 2020; formerly reported as Macoma balthica and M. petalum), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer (km) south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francis
Authors
Daniel J. Cain, Marie Noële Croteau, Janet K. Thompson, Francis Parchaso, A. Robin Stewart, Emily L. Zierdt Smith, Kelly H. Shrader, Le H. Kieu, Samuel N. Luoma
By
Water Resources Mission Area, Geology, Minerals, Energy, and Geophysics Science Center

Bivalve effects on the food web supporting delta smelt—A long-term study of bivalve recruitment, biomass, and grazing rate patterns with varying freshwater outflow

Phytoplankton are an important and limiting food source in the Sacramento-San Joaquin Delta and San Francisco Bay in California. Decreasing phytoplankton biomass is one possible factor for the pelagic organism decline and the decline of the protected Hypomesus transpacificus (delta smelt). Bivalves Corbicula fluminea and Potamocorbula amurensis (hereafter C. fluminea and P. amurensis, respectively
Authors
Emily L. Zierdt Smith, Kelly H. Shrader, Janet K. Thompson, Francis Parchaso, Karen Gehrts, Elizabeth Wells
By
Water Resources Mission Area

Bivalve effects on the food web supporting delta smelt—A spatially intensive study of bivalve recruitment, biomass, and grazing rate patterns with varying freshwater outflow in 2019

Phytoplankton are an important and limiting food source in the Sacramento-San Joaquin Delta and San Francisco Bay. The decline of phytoplankton biomass is one potential factor in the decline of the protected Hypomesus transpacificus (delta smelt) and other pelagic organisms. The bivalves Corbicula fluminea and Potamocorbula amurensis (hereafter C. fluminea and P. amurensis, respectively) have been
Authors
Emily L. Zierdt Smith, Kelly H. Shrader, Janet K. Thompson, Francis Parchaso, Karen Gehrts, Elizabeth Wells
By
Water Resources Mission Area

Near-field receiving-water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California—2019

Trace-metal concentrations in sediment and in the clam Limecola petalum (formerly reported as Macoma balthica and M. petalum), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, Calif. This report includes the data
Authors
Daniel J. Cain, Marie Noële Croteau, Janet K. Thompson, Francis Parchaso, A. Robin Stewart, Kelly H. Shrader, Emily L. Zierdt Smith, Samuel N. Luoma
By
Water Resources Mission Area

Effect of the emergency drought barrier on the distribution, biomass, and grazing rate of the bivalves Corbicula fluminea and Potamocorbula amurensis, False River, California

Executive SummaryBenthic samples were collected from the Sacramento–San Joaquin Delta of northern California to examine the effect of the changing hydrologic flow on the bivalves Potamocorbula and Corbicula before, during, and after the False River Barrier (hereafter, barrier) was in operation (May–November 2015). Potamocorbula moved upstream in the Sacramento River as the salinity intruded. Given
Authors
Francis Parchaso, Emily L. Zierdt Smith, Janet K. Thompson
By
Water Resources Mission Area

If you give a clam an estuary: The story of potamocorbula

When you look at San Francisco Bay, what animals do you see? You may see lots of fish swimming around and birds flying above. What you DON’T see is Potamocorbula, a little clam that has had a big impact. Many years ago, ships accidentally brought Potamocorbula into the Bay. Pretty soon, Potamocorbula spread out all over in large numbers! Clams pump water over their gills and eat small particles of
Authors
Kelly H. Shrader, Emily L. Zierdt Smith, Francis Parchaso, Janet K. Thompson
By
Water Resources Mission Area

Benthic community dynamics in Coyote Creek and Artesian Slough, southern San Francisco Bay, California, May 2016 to March 2018

The primary objective of this study is to quantify current (2016–18) benthic-community structure and function in the southern San Francisco Bay, and to compare those communities to the communities in the neighboring sloughs. The study area is inclusive of the area south of the Dumbarton Bridge including Coyote Creek and Artesian Slough.   The southern San Francisco Bay is a system dependent on phy
Authors
Kelly H. Shrader, Sarah A. Pearson, Francis Parchaso, Janet K. Thompson

Near-field receiving-water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California—2017

Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, Calif. This report includes the data collected by U.S.
Authors
Daniel J. Cain, Janet K. Thompson, Francis Parchaso, Sarah Pearson, A. Robin Stewart, Matthew A. Turner, David Barasch, Ane Slabic, Samuel N. Luoma
By
Water Resources Mission Area

Conceptual model for invasive bivalve control on wetland productivity

Tidal wetlands were the historically dominant features of many coastal regions around the world, including the San Francisco Estuary (Callaway et al. 2011; Whipple et al. 2012). These mosaics of varied interconnected habitats (Mitsch and Gosselink 1993) provide a host of ecosystem services, including biodiversity maintenance, fish and wildlife habitat, water quality improvement, flood abatement, a
Authors
Rosemary Hartman, Larry R. Brown, Janet K. Thompson, Francis Parchaso
By
Water Resources Mission Area

Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California; 2016

Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, Calif. This report includes the data collected by U.S.
Authors
Daniel J. Cain, Janet K. Thompson, Francis Parchaso, Sarah A. Pearson, A. Robin Stewart, Mathew Turner, David Barasch, Samuel N. Luoma
By
Water Resources Mission Area

Benthic processes affecting contaminant transport in Upper Klamath Lake, Oregon

Executive SummaryMultiple sampling trips during calendar years 2013 through 2015 were coordinated to provide measurements of interdependent benthic processes that potentially affect contaminant transport in Upper Klamath Lake (UKL), Oregon. The measurements were motivated by recognition that such internal processes (for example, solute benthic flux, bioturbation and solute efflux by benthic invert
Authors
James S. Kuwabara, Brent R. Topping, James L. Carter, Rick A Carlson, Francis Parchaso, Steven V. Fend, Natalie Stauffer-Olsen, Andrew J. Manning, Jennie M. Land
By
Water Resources Mission Area

Science and Products

Benthic Communities as Mediators of Water Quality in Lower San Francisco Bay, California (2012-2019)

San Francisco Bay and Estuary is largely urbanized and developed, and the southern bay is the most urbanized with many sources of nutrients, many concerns that the system might become eutrophic, and many questions about how South Bay has maintained its relatively good health. The hypotheses for why South Bay is not eutrophic, where other bays have not been so fortunate, include high bivalve grazin
By
Water Resources Mission Area

Data for monitoring trace metal and benthic community near the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay, California (ver 2.0, November 2022)

Trace-metal concentrations in sediment and in the clam Limecola petalum (World Register of Marine Species, 2020; formerly reported as Macoma balthica and M. petalum), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat located 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Fran
By
Water Resources Mission Area

Bivalve metrics in the North San Francisco Bay and Sacramento-San Joaquin Delta

Phytoplankton is an important and limiting food source in the Sacramento-San Joaquin Delta and San Francisco Bay; the decline of phytoplankton biomass is one possible factor in the pelagic organism decline and specifically in the decline of the protected delta smelt. The bivalves Corbicula fluminea and Potamocorbula amurensis (hereafter Corbicula and Potamocorbula, respectively) have been shown to
By
Water Resources Mission Area

Priority Ecosystem Science Program: benthic community and bivalve metrics data in Grizzly Bay and San Pablo Bay (2019-20)

Sediments and sediment transport influence the physical habitat and the ecology of the San Francisco Bay estuary. Bed sediments provide habitat for benthic organisms and the transport of sediment transports nutrients and contaminants throughout the San Francisco Bay. As part of the SF Bay-Delta Priority Ecosystems Science Program project: Biophysical Controls on Erosion and Near-Bed Turbulence: St
By
Water Resources Mission Area

A spatially and temporally intensive sampling study of benthic community and bivalve metrics in the Sacramento-San Joaquin Delta, 2007-18

Phytoplankton is an important and limiting food source in the Sacramento-San Joaquin Delta and San Francisco Bay; the decline of phytoplankton biomass is one possible factor in the pelagic organism decline and specifically in the decline of the protected delta smelt. The bivalves Corbicula fluminea and Potamocorbula amurensis (hereafter Corbicula and Potamocorbula, respectively) have been shown to
By
Water Resources Mission Area

Benthic Community and Bivalve Metrics Data in the Sacramento - San Joaquin Delta from 2015 to 2018

Declining phytoplankton biomass and the resulting stress on the food web has been suggested as one contributor to the decline of Delta Smelt and other fish species in the San Francisco Bay (SFB) and the Sacramento San Joaquin River Delta. Filter feeding by two species of bivalves, Corbicula fluminea and Potamocorbula amurensis, has been shown to control phytoplankton growth rate in the SFB and Del
By
Water Resources Mission Area
Moutain Diablo in the early morning
Mt. Diablo from Suisun Marsh
Mt. Diablo from Suisun Marsh
Moutain Diablo in the early morning

Mt. Diablo from Suisun Marsh

Mt. Diablo from Suisun Marsh

Picturesque view of Mt.Diablo early in the morning from Suisun Marsh.

Moutain Diablo in the early morning

Mt. Diablo from Suisun Marsh

Mt. Diablo from Suisun Marsh

Picturesque view of Mt.Diablo early in the morning from Suisun Marsh.

Water quality sampling using a Niskin sampler from the Research Vessel Polaris at sunset on San Francisco Bay.
Water quality sampling on San Francisco Bay
Water quality sampling on San Francisco Bay
Water quality sampling using a Niskin sampler from the Research Vessel Polaris at sunset on San Francisco Bay.

Water quality sampling on San Francisco Bay

Water quality sampling on San Francisco Bay

USGS conducts water quality sampling to describe changes in water quality along the deep channel of the San Francisco Bay-Delta system. Sampling includes continuious sampling and discrete sampling. Here a water discrete water sample is collected using a Niskin sampler at sunset in north San Francisco Bay.

By
Water Resources
Water quality sampling using a Niskin sampler from the Research Vessel Polaris at sunset on San Francisco Bay.

Water quality sampling on San Francisco Bay

Water quality sampling on San Francisco Bay

USGS conducts water quality sampling to describe changes in water quality along the deep channel of the San Francisco Bay-Delta system. Sampling includes continuious sampling and discrete sampling. Here a water discrete water sample is collected using a Niskin sampler at sunset in north San Francisco Bay.

By
Water Resources
Image: Research Vessel Polaris
Research Vessel Polaris
Research Vessel Polaris
Image: Research Vessel Polaris

Research Vessel Polaris

Research Vessel Polaris

San Fracisco Bay, CA; Amy Little on Research Vessel Polaris, sampling for water quality constitutents.

By
Water Resources, Communications and Publishing
Image: Research Vessel Polaris

Research Vessel Polaris

Research Vessel Polaris

San Fracisco Bay, CA; Amy Little on Research Vessel Polaris, sampling for water quality constitutents.

By
Water Resources, Communications and Publishing
Image: Suisun Slough, California
Suisun Slough, California
Suisun Slough, California
Image: Suisun Slough, California

Suisun Slough, California

Suisun Slough, California

A small slough in Suisun Slough in the Suisun Bay, California.

By
Ecosystems, Communications and Publishing
Image: Suisun Slough, California

Suisun Slough, California

Suisun Slough, California

A small slough in Suisun Slough in the Suisun Bay, California.

By
Ecosystems, Communications and Publishing
Image: Golden Gate Bridge, California
Golden Gate Bridge, California
Golden Gate Bridge, California
Image: Golden Gate Bridge, California

Golden Gate Bridge, California

Golden Gate Bridge, California

The Golden Gate Bridge seen through Racoon Strait in the San Francisco Bay, California.

By
Ecosystems, Communications and Publishing
Image: Golden Gate Bridge, California

Golden Gate Bridge, California

Golden Gate Bridge, California

The Golden Gate Bridge seen through Racoon Strait in the San Francisco Bay, California.

By
Ecosystems, Communications and Publishing
Image: Sunrise on the Suisun Bay
Sunrise on the Suisun Bay
Sunrise on the Suisun Bay
Image: Sunrise on the Suisun Bay

Sunrise on the Suisun Bay

Sunrise on the Suisun Bay

Sunrise peering through early morning tule fog in Suisun Bay, California.

By
Ecosystems, Communications and Publishing
Image: Sunrise on the Suisun Bay

Sunrise on the Suisun Bay

Sunrise on the Suisun Bay

Sunrise peering through early morning tule fog in Suisun Bay, California.

By
Ecosystems, Communications and Publishing
Image: Sunrise on the Sacramento River
Sunrise on the Sacramento River
Sunrise on the Sacramento River
Image: Sunrise on the Sacramento River

Sunrise on the Sacramento River

Sunrise on the Sacramento River

Sunrise reflecting on a November morning on the Sacramento River, California.

By
Ecosystems, Communications and Publishing
Image: Sunrise on the Sacramento River

Sunrise on the Sacramento River

Sunrise on the Sacramento River

Sunrise reflecting on a November morning on the Sacramento River, California.

By
Ecosystems, Communications and Publishing
Filter Total Items: 47

Physics to fish—Understanding the factors that create and sustain native fish habitat in the San Francisco Estuary

Executive SummaryThe Bureau of Reclamation (Reclamation) operates the Central Valley Project (CVP), one of the nation’s largest water projects. Reclamation has an ongoing need to improve the scientific basis for adaptive management of the CVP and, by extension, joint operations with California’s State Water Project. The U.S. Geological Survey (USGS) works cooperatively with the Bureau of Reclamati
Authors
Larry R. Brown, David E. Ayers, Brian A. Bergamaschi, Jon R. Burau, Evan T. Dailey, Bryan D. Downing, Maureen A. Downing-Kunz, Frederick V. Feyrer, Brock M. Huntsman, Tamara E. C. Kraus, Tara Morgan, Jessica R. Lacy, Francis Parchaso, Catherine A. Ruhl, Elizabeth B. Stumpner, Paul Stumpner, Janet Thompson, Matthew J. Young
By
Water Resources Mission Area, California Water Science Center, Pacific Coastal and Marine Science Center

Near-field receiving-water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California—2020

Trace-metal concentrations in sediment and in the clam Limecola petalum (World Register of Marine Species, 2020; formerly reported as Macoma balthica and M. petalum), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer (km) south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francis
Authors
Daniel J. Cain, Marie Noële Croteau, Janet K. Thompson, Francis Parchaso, A. Robin Stewart, Emily L. Zierdt Smith, Kelly H. Shrader, Le H. Kieu, Samuel N. Luoma
By
Water Resources Mission Area, Geology, Minerals, Energy, and Geophysics Science Center

Bivalve effects on the food web supporting delta smelt—A long-term study of bivalve recruitment, biomass, and grazing rate patterns with varying freshwater outflow

Phytoplankton are an important and limiting food source in the Sacramento-San Joaquin Delta and San Francisco Bay in California. Decreasing phytoplankton biomass is one possible factor for the pelagic organism decline and the decline of the protected Hypomesus transpacificus (delta smelt). Bivalves Corbicula fluminea and Potamocorbula amurensis (hereafter C. fluminea and P. amurensis, respectively
Authors
Emily L. Zierdt Smith, Kelly H. Shrader, Janet K. Thompson, Francis Parchaso, Karen Gehrts, Elizabeth Wells
By
Water Resources Mission Area

Bivalve effects on the food web supporting delta smelt—A spatially intensive study of bivalve recruitment, biomass, and grazing rate patterns with varying freshwater outflow in 2019

Phytoplankton are an important and limiting food source in the Sacramento-San Joaquin Delta and San Francisco Bay. The decline of phytoplankton biomass is one potential factor in the decline of the protected Hypomesus transpacificus (delta smelt) and other pelagic organisms. The bivalves Corbicula fluminea and Potamocorbula amurensis (hereafter C. fluminea and P. amurensis, respectively) have been
Authors
Emily L. Zierdt Smith, Kelly H. Shrader, Janet K. Thompson, Francis Parchaso, Karen Gehrts, Elizabeth Wells
By
Water Resources Mission Area

Near-field receiving-water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California—2019

Trace-metal concentrations in sediment and in the clam Limecola petalum (formerly reported as Macoma balthica and M. petalum), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, Calif. This report includes the data
Authors
Daniel J. Cain, Marie Noële Croteau, Janet K. Thompson, Francis Parchaso, A. Robin Stewart, Kelly H. Shrader, Emily L. Zierdt Smith, Samuel N. Luoma
By
Water Resources Mission Area

Effect of the emergency drought barrier on the distribution, biomass, and grazing rate of the bivalves Corbicula fluminea and Potamocorbula amurensis, False River, California

Executive SummaryBenthic samples were collected from the Sacramento–San Joaquin Delta of northern California to examine the effect of the changing hydrologic flow on the bivalves Potamocorbula and Corbicula before, during, and after the False River Barrier (hereafter, barrier) was in operation (May–November 2015). Potamocorbula moved upstream in the Sacramento River as the salinity intruded. Given
Authors
Francis Parchaso, Emily L. Zierdt Smith, Janet K. Thompson
By
Water Resources Mission Area

If you give a clam an estuary: The story of potamocorbula

When you look at San Francisco Bay, what animals do you see? You may see lots of fish swimming around and birds flying above. What you DON’T see is Potamocorbula, a little clam that has had a big impact. Many years ago, ships accidentally brought Potamocorbula into the Bay. Pretty soon, Potamocorbula spread out all over in large numbers! Clams pump water over their gills and eat small particles of
Authors
Kelly H. Shrader, Emily L. Zierdt Smith, Francis Parchaso, Janet K. Thompson
By
Water Resources Mission Area

Benthic community dynamics in Coyote Creek and Artesian Slough, southern San Francisco Bay, California, May 2016 to March 2018

The primary objective of this study is to quantify current (2016–18) benthic-community structure and function in the southern San Francisco Bay, and to compare those communities to the communities in the neighboring sloughs. The study area is inclusive of the area south of the Dumbarton Bridge including Coyote Creek and Artesian Slough.   The southern San Francisco Bay is a system dependent on phy
Authors
Kelly H. Shrader, Sarah A. Pearson, Francis Parchaso, Janet K. Thompson

Near-field receiving-water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California—2017

Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, Calif. This report includes the data collected by U.S.
Authors
Daniel J. Cain, Janet K. Thompson, Francis Parchaso, Sarah Pearson, A. Robin Stewart, Matthew A. Turner, David Barasch, Ane Slabic, Samuel N. Luoma
By
Water Resources Mission Area

Conceptual model for invasive bivalve control on wetland productivity

Tidal wetlands were the historically dominant features of many coastal regions around the world, including the San Francisco Estuary (Callaway et al. 2011; Whipple et al. 2012). These mosaics of varied interconnected habitats (Mitsch and Gosselink 1993) provide a host of ecosystem services, including biodiversity maintenance, fish and wildlife habitat, water quality improvement, flood abatement, a
Authors
Rosemary Hartman, Larry R. Brown, Janet K. Thompson, Francis Parchaso
By
Water Resources Mission Area

Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California; 2016

Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, Calif. This report includes the data collected by U.S.
Authors
Daniel J. Cain, Janet K. Thompson, Francis Parchaso, Sarah A. Pearson, A. Robin Stewart, Mathew Turner, David Barasch, Samuel N. Luoma
By
Water Resources Mission Area

Benthic processes affecting contaminant transport in Upper Klamath Lake, Oregon

Executive SummaryMultiple sampling trips during calendar years 2013 through 2015 were coordinated to provide measurements of interdependent benthic processes that potentially affect contaminant transport in Upper Klamath Lake (UKL), Oregon. The measurements were motivated by recognition that such internal processes (for example, solute benthic flux, bioturbation and solute efflux by benthic invert
Authors
James S. Kuwabara, Brent R. Topping, James L. Carter, Rick A Carlson, Francis Parchaso, Steven V. Fend, Natalie Stauffer-Olsen, Andrew J. Manning, Jennie M. Land
By
Water Resources Mission Area
Was this page helpful?