Picturesque view of Mt.Diablo early in the morning from Suisun Marsh.
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)
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)
Bivalve metrics in the North San Francisco Bay and Sacramento-San Joaquin Delta
Priority Ecosystem Science Program: benthic community and bivalve metrics data in Grizzly Bay and San Pablo Bay (2019-20)
A spatially and temporally intensive sampling study of benthic community and bivalve metrics in the Sacramento-San Joaquin Delta, 2007-18
Benthic Community and Bivalve Metrics Data in the Sacramento - San Joaquin Delta from 2015 to 2018
Picturesque view of Mt.Diablo early in the morning from Suisun Marsh.
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.
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.
San Fracisco Bay, CA; Amy Little on Research Vessel Polaris, sampling for water quality constitutents.
San Fracisco Bay, CA; Amy Little on Research Vessel Polaris, sampling for water quality constitutents.
A small slough in Suisun Slough in the Suisun Bay, California.
A small slough in Suisun Slough in the Suisun Bay, California.
The Golden Gate Bridge seen through Racoon Strait in the San Francisco Bay, California.
The Golden Gate Bridge seen through Racoon Strait in the San Francisco Bay, California.
Sunrise peering through early morning tule fog in Suisun Bay, California.
Sunrise peering through early morning tule fog in Suisun Bay, California.
Sunrise reflecting on a November morning on the Sacramento River, California.
Sunrise reflecting on a November morning on the Sacramento River, California.
Physics to fish—Understanding the factors that create and sustain native fish habitat in the San Francisco Estuary
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
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
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
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
Effect of the emergency drought barrier on the distribution, biomass, and grazing rate of the bivalves Corbicula fluminea and Potamocorbula amurensis, False River, California
If you give a clam an estuary: The story of potamocorbula
Benthic community dynamics in Coyote Creek and Artesian Slough, southern San Francisco Bay, California, May 2016 to March 2018
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
Conceptual model for invasive bivalve control on wetland productivity
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
Benthic processes affecting contaminant transport in Upper Klamath Lake, Oregon
Science and Products
- Data
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 grazinData 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 FranBivalve 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 toPriority 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: StA 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 toBenthic 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 - Multimedia
Mt. Diablo from Suisun Marsh
Picturesque view of Mt.Diablo early in the morning from Suisun Marsh.
Picturesque view of Mt.Diablo early in the morning from Suisun Marsh.
Water quality sampling on San Francisco BayUSGS 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.
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.
Research Vessel PolarisSan Fracisco Bay, CA; Amy Little on Research Vessel Polaris, sampling for water quality constitutents.
San Fracisco Bay, CA; Amy Little on Research Vessel Polaris, sampling for water quality constitutents.
Suisun Slough, CaliforniaA small slough in Suisun Slough in the Suisun Bay, California.
A small slough in Suisun Slough in the Suisun Bay, California.
Golden Gate Bridge, CaliforniaThe Golden Gate Bridge seen through Racoon Strait in the San Francisco Bay, California.
The Golden Gate Bridge seen through Racoon Strait in the San Francisco Bay, California.
Sunrise on the Suisun BaySunrise peering through early morning tule fog in Suisun Bay, California.
Sunrise peering through early morning tule fog in Suisun Bay, California.
Sunrise on the Sacramento RiverSunrise reflecting on a November morning on the Sacramento River, California.
Sunrise reflecting on a November morning on the Sacramento River, California.
- Publications
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 ReclamatiAuthorsLarry 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. YoungNear-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 FrancisAuthorsDaniel 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. LuomaBivalve 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, respectivelyAuthorsEmily L. Zierdt Smith, Kelly H. Shrader, Janet K. Thompson, Francis Parchaso, Karen Gehrts, Elizabeth WellsBivalve 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 beenAuthorsEmily L. Zierdt Smith, Kelly H. Shrader, Janet K. Thompson, Francis Parchaso, Karen Gehrts, Elizabeth WellsNear-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 dataAuthorsDaniel J. Cain, Marie-Noële Croteau, Janet K. Thompson, Francis Parchaso, A. Robin Stewart, Kelly H. Shrader, Emily L. Zierdt Smith, Samuel N. LuomaEffect 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. GivenAuthorsFrancis Parchaso, Emily L. Zierdt Smith, Janet K. ThompsonIf 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 ofAuthorsKelly H. Shrader, Emily L. Zierdt Smith, Francis Parchaso, Janet K. ThompsonBenthic 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 phyAuthorsKelly H. Shrader, Sarah A. Pearson, Francis Parchaso, Janet K. ThompsonNear-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.AuthorsDaniel J. Cain, Janet K. Thompson, Francis Parchaso, Sarah Pearson, A. Robin Stewart, Matthew A. Turner, David Barasch, Ane Slabic, Samuel N. LuomaConceptual 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, aAuthorsRosemary Hartman, Larry R. Brown, Janet K. Thompson, Francis ParchasoNear-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.AuthorsDaniel J. Cain, Janet K. Thompson, Francis Parchaso, Sarah A. Pearson, A. Robin Stewart, Mathew Turner, David Barasch, Samuel N. LuomaBenthic 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 invertAuthorsJames 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